Sunday, December 28, 2008

GPT for FreeBSD!

A lot has changed since the PC was first introduced in the early 1980s. Unfortunately, a lot of legacy nonsense has remained behind that has to be hacked-around because of that history. In essence, a modern Intel based computer starts the boot process as an 8088 and, effectively, climbs up out of the primordial ooze stepwise, getting a little more advanced with each tweak.

One of those bits of legacy nonsense still with us is the old FDISK based partitioning scheme, which still has nonsense like cylinders, heads and sectors in it (which mean nothing at all to modern disks, which in essence are just single-dimensioned arrays of 512 byte blocks).

FreeBSD has existed within this framework by using the old BSD "slice" system to chop up a single FDISK partition. Linux, instead, has tended to use FDISK extended partitioning, but that has led, to some extent, to Linux systems living in a single filesystem. One of the benefits of the multi-partitioning that FreeBSD uses instead are that two of the typical partitions (/ and /usr) tend to be "read-mostly," while the other two (/var and /home) tend to have the majority of write activity. This is somewhat safer, since the volatility is kept away from important configuration data (in /etc) and system code (in /boot and /usr).

Macs have discarded a lot of the Intel legacy, since they don't have to boot 20 year old operating systems (instead, they boot Unix, which is a 30 year old operating system, but I digress). So the Intel macs have adopted GPT partitioning. GPT is great, since it can operate on disks with 2^64 blocks, which is ridiculously huge, and the number of partitions is unlimited (it's actually limited to the number of blocks allocated to the GPT itself, and by default it's 128 entries).

Well, with the advent of FreeBSD 7.1, support has been added to boot from a GPT partitioned disk. The way this works is that the legacy FDISK partition (which basically marks the entire disk as allocated to protect against FDISK based tools trying to do something to the disk) contains boot code that looks for a special GPT partition that contains the second stage boot loader. That partition and the FDISK boot sector is written with the 'gpt boot' command. That boot loader looks for the first UFS partition on the disk and loads the main FORTH-based loader, which in turn loads the kernel and so on.

Just to be on the safe side, I migrated my setup by buying a new disk (a 320GB disk for $55 - can't go wrong!), partitioning it and then copying all the stuff over. As a bonus, the new disk is faster than the old one, and we get to start the warranty over.

There is, however, a 'gpt migrate' command that purports to convert a disk from FDISK and BSD slice format to GPT, but that concept sounds a bit scary to me, at least for filesystems I really care about. :)

One interesting thing is that the gpt command opens the disk for writing, even if all you want to do is read information. But if there are mounted partitions, then this will fail. There is a -r option that will make the open read-only, which is useful for the 'show' command.

Now that the disk is GPT partitioned, converting to an EFI based machine would simply require replacing the special FreeBSD boot partition with an EFI system partition (it would need to be slightly larger, but space from the adjacent swap partition could be stolen), and EFI boot code for FreeBSD would need to be added to it (if it existed).

FreeBSD 7.1 hasn't yet has been released - it's at RC2 at the moment - but - on new year's day, in fact. I'm quite happy with it.

Friday, December 19, 2008

iPhone dartboard navigation

When I was waiting to turn left from San Tomas Expressway onto Saratoga Ave, I happened to glance down at my phone to see it tell me this:



Come on! That's not even the same zip code! Hell, it's not even the same city! It's the city two cities away! Oops.

Google hosed me

I took my car in for service last night, with the plan being to take CalTrain from work, as usual, but get off at the station close to the dealership and walk to go pick it up.

I settled on this plan because when I asked the iPhone's Google Maps app to give me directions from "Sunnyvale Caltrain" to Sunnyvale VW, it said that the route was about a mile.

Well, it appears that it decided that "Sunnyvale Caltrain" meant any CalTrain station in Sunnyvale... of which there are two. It's about 1 mile from the Lawrence station to Sunnyvale VW, but it's about 3 miles from the Sunnyvale CalTrain station. If it had said that it was a 3 mile walk and showed me a mostly southerly route, I probably would have known to try Lawrence instead.

So, thanks, Google. You clearly knew best when you thought I didn't mean the Sunnyvale CalTrain station when that's exactly what I typed in.

Wednesday, December 17, 2008

JBoss and custom LoginModules for data sources

This is rather a specialized topic, but precious little has been said about it, so I figure it's worth a mention.

A data source in JBoss is typically either a JMS or JDBC connection pool, more or less. It represents a resource within JBoss that you can turn to to obtain the thing you want, use it, then throw it away (typically the connections are wrapped with code that catches the "close()" call and rather than closing the connection returns it to the available pool).

If the resource represents a database or remote JMS server, you're going to need to authenticate - typically by providing a username and password. In most enterprise situations, you don't want those passwords to be in plaintext in the configuration files. Rather, you have either some sort of configurable password encryption system or a password fetching system. In every shop I've worked in so far where this has been an issue, there's been a pre-existing mechanism that is set in concrete and must be used more or less without modification to obtain passwords to connect to enterprise resources.

Well, if you're configuring a data source within JBoss, you give that data source an <application-and-security-domain>, which is a <application-policy> node within server/___/conf/login-config.xml, which contains a <authentication> section which provides the username and password. The question is, how can you provide the bridge between JBoss and your established mechanism for providing username and password? Naively, the answer is that you must write your own custom JAAS login module.

Fortunately, there is a much easier way.

JBoss provides a ConfiguredIdentityLoginModule, which is simply a wrapper for a plaintext username and password. The simplest way to wire in your own password fetching code is to extend this module. You simply need to replace this method in the class:

public void initialize(Subject subject, CallbackHandler handler, Map sharedState, Map options)

The "options" map is a map of the list of module-options from login-config.xml. You simply call super.initialize() with all of the same arguments, but with a different options map. The new options map will have in it the "username" and plaintext "password" options that are required by the ConfiguredIdentityLoginModule.

For example, if you have a CryptoWidget that can decrypt passwords, you'd write something like this:


public void initialize(Subject subject, CallbackHandler handler, Map sharedState, Map options) {
Map newOptions = new HashMap(options);
String pw = (String) newOptions.get("password");
pw = CryptoWidget.decrypt(pw);
newOptions.put("password", pw);
newOptions = Collections.unmodifiableMap(newOptions);
super.initialize(subject, handler, sharedState, options);
}


And that, more or less, is the entire class. You can do anything you need to modify the options map, so long as the options map you pass in to super.initialize() is what the superclass expects to get. It might be a good idea to remove any options that you require that the superclass does not require. For instance, if a "salt" option was required to pass some additional argument into the CryptoWidget, you'd fetch it, then remove it from newOptions.

Incidentally, it is necessary to make a copy of the options map because it is an unmodifiable map (note that we make newOptions unmodifiable before calling super.initialize() also).

Saturday, December 13, 2008

Next ATSC test: 1/10, 33 cm

Well, despite the complete lack of success at 420 MHz, I'll be trying again on January 10th with the new 900 MHz amp. I'll be putting out around 75 watts or so of ATSC on 910-916 MHz into a KP-20, for a total of about 380 watts of ERP. I liked the Cañada college QTH when I was there last, so that's where I'll be this time.

Of course, in the meantime, I'll need to get ahold of a 28 VDC power supply and a small generator to run it.

Sunday, December 7, 2008

Building a VHF TV dipole

After 2/17 of next year, there will be only two broadcasters below channel 14 here in the San Francisco market: KGO on channel 7 and KNTV on channel 11.

You could make do with a UHF corner Yagi... but what about those two channels?

Well, the ChannelMaster CM2016 is a good solution. It's a traditional UHF corner Yagi antenna combined with a VHF-hi dipole. But if you already have a UHF corner Yagi, there's no need to replace it. You can simply add your own VHF-hi dipole. Even better, you could make a relatively high quality folded dipole from copper plumbing pipe.

After February, the two channels that matter will be 7 and 12. 7 has a bottom of 174 MHz, 12's top is at 210 MHz. Halfway between those two is 192 MHz. A half wavelength at 192 MHz is 2.43 feet, or 29 1/4 inches, but we're going to put some fittings on each end, so subtract two inches, for 27 1/4". You'll need two pieces of 1/2" copper pipe that long, 2 90 degree 1/2" "street" elbows and two 90 degree 1/2" normal elbows. "Street" elbows are designed so that one side is the same diameter as the pipe itself, so that it can mate with one of the ordinary elbows to make a 180 degree turn.

Cut a half inch off one of the long pieces of copper and then cut that piece in half. Assemble the two ends out of one of each type of elbow. Put one of the combo elbows on each end of the long piece, and then stick a short piece in each remaining open elbow connection. The two short pieces should have a half inch gap between them. Once it is all dry-fit properly, use a plumber's torch and sweat the whole thing together. Use sheet metal screws to attach a standard TV balun on each side of the gap.

The only trick remaining is to mount the thing. You want the dipole to be at a right angles to the direction from your location to Mt. San Bruno and Sutro Tower. You need to use a piece of wood or plastic or something insulating to attach it to your mast. You also need to keep it at least a couple feet away from any other antenna on your mast, if you can.

Saturday, December 6, 2008

Joel McHale at the Flint Center

Joel McHale has a message for all his fans:



Actually, no, Joel was very nice. As he was finishing his act, he told the entire assembled multitude (a sell-out crowd at the Flint Center) that he'd sign stuff for everyone afterwards, which I believe came as a shock to the house staff, since there were no preparations whatsoever for the resulting huge mob that gathered in the lobby around the merch booth. I waited an hour and a half to walk 5 feet.

If you go to the mall to visit Santa, the line is very orderly, but you don't get to have lots of chicks mashing their tits into your elbow.

Naturally, the ATM machine was broke, so I asked Joel if he'd let me slide on the T-shirt price by $5 (they were $25, but I only had $20). He signed my ticket, and let me take the picture you see above. When we got out, I told Scarlet the story and she said she had $5, but only had $4. We gave his bodyguard the $4 and had him pass it up to Joel and we left before he counted it. I'm sure that he made a snarky comment about it.

I'm actually going to put a dollar in the mail and send it to him (at E!). Just so he knows I'm not really cheap.

If you're a fan of The Soup (and don't you dare call it Talk Soup), you really should try and catch him if he comes near your town. It's great.

Sunday, November 30, 2008

New Water Heater

Well, there are only two major appliances in the house that we hadn't replaced since moving in - the furnace / AC and the water heater. And now, there's just one. The water heater started leaking and set off the flood detector Friday morning. We called our favorite plumber (Gus at Castle Plumbing), and he said he could come out and take a look Saturday, but that if it needed to be replaced and we couldn't wait until Monday that that likely meant getting a new water heater at Home Depot, since nothing else would be open. But the good news is that the Home Depot water heaters are made by Rheem, which has a good track record.

In the meantime, we called a national plumbing chain (I won't mention their name) and they sent someone out who gave us a free estimate of $1300, but who knows whether they would have put a good water heater in for that price? In any event, that's way, way too much, so they were dismissed.

Saturday came around and I decided that it was just too likely that the water heater had to be replaced. It was 11 years old, and I strongly suspected that it wasn't the 12 year warranty kind. One thing you can take to the bank is that an N year warranty water heater will last for about N years + 1 day before giving out. So I decided to attempt to save some money by at least starting the demolition of the old unit myself. It was pretty easy, and I managed to get the old unit out all by myself. The gas and water connections came off with a wrench. The T&P relief valve had a sweated connection that I needed to desolder before I could unscrew the rest of it. Lastly, the chimney was held on with a couple of sheet metal screws.

We went to Home Depot and bought a 12 year warranty 40 gallon natural gas heater. It was about $550 or so, but the extra-cheap 6 year warranty units were about $400, so I think that's pretty clearly money well spent.

In retrospect, I probably could have installed the new unit myself. The new unit is a little taller than the old one was, because between then and now the building code has an added safety requirement - a special sealed combustion chamber that has a spring-loaded door held open by a thermal fuse. The idea is that if the burner area overheats, the door will spring shut cutting off the combustion air flow, choking off the fire. I had Gus install the new water heater mostly because of the fear that the size difference was going to make a difference between it being easy and being hard. The worry was that the water connections were going to need to be moved, which would have involved tearing out some sheetrock in the back of the water heater alcove. But there are flexible copper pipes and there was enough flex left for the new heater to fit. The only other work needed was to trim the chimney to fit and to re-plumb the T&P relief piping.

The last advice Gus had was to keep the home depot receipt, because Home Depot has a reputation for doing anything they can to low-ball you on any warranty claims. I stapled it to the door of the water heater closet. He also said we should drain it once a year, but that didn't mean emptying it all the way - just opening the drain valve and pouring off a gallon or two is enough.

Thursday, November 27, 2008

Thanksgiving Turkey Fry



We fried our turkey again. This time, the event was transmitted to the K6BEN ATV repeater for anyone who wanted to tune it in. Scarlet used our digital camera to capture the drop and retrieval operation.

Wednesday, November 26, 2008

Cringely stupidity

Sometimes Bob comes up with a real boner.

My hobby is building small airplanes and one of my favorites is a Davis DA-2A, winner of the Outstanding New Design contest in 1966, the same year my Oldsmobile (and my current Thunderbird convertible) was built. That little Davis can teach us a lot about cars.

I didn't build my DA-2A, but I am rebuilding it right now and know it intimately. My Davis is an all-aluminum two-seater with an 85-horsepower engine. The engine was built in 1946, the plane in 1982, and the whole thing cost under $4,000 at the time, though today I have more than that invested in the instrument panel alone. The plane weighs 625 lbs. empty, 1125 lbs. loaded, has a top speed of 140 miles per hour and can travel about 600 miles on its 24-gallon fuel tank.

Why can't I buy a car like that?


Um, because a fender-bender would kill everyone, stupid!

Cars used to be made like that airplane of yours. Then Ralph Nader wrote a little book called "Unsafe At Any Speed," and the fit hit the shan.

The threat model for airplanes and cars are entirely different, which requires entirely different priorities. Cars need to be crashworthy, because crashes are very, very frequent compared to airplanes.

Those who can't, teach. Those too stupid to even teach, commentate.

Sunday, November 23, 2008

Pictures from an Expedition

With apologies for the terrible pun to Modest Musorgsky.




Saturday, November 22, 2008

Results from the test transmission

Well, I don't think very many people were able to see the signal, much less get a picture. The closest was Joel, KD6W, the vice president of PAARA. He wasn't able to decode the signal, but he was able to see the pilot show up. On the way home, on his advice, I stopped at Cañada College and parked at a spot that had excellent coverage and tried again. From there, Joel (who was at his house in Menlo Park) captured this trace on his spectrum analyzer:



It's just not quite enough to display

So 10 watts of output power, or 50 watts of ERP don't hardly get you much, I guess.

Leaving for the mountain

See you all at 1:30 on 420 MHz and 146.76 MHz!

Friday, November 21, 2008

An overview of different digital modulation schemes

There are 3 main ways that digital TV is modulated and transmitted nowadays: 8VSB, QAM and OFDM. Here's a little bit of introduction into each:

I've talked about 8VSB quite a bit on this blog. It is 8 level Vestigial SideBand modulation. Reducing it to its most basic description, you take a carrier and amplitude modulate it with a square wave that has 8 different legal amplitude levels. The result is a tremendously wide double-sideband signal. You then pass that signal through a Nyquist filter that reduces the signal down to 6 MHz of bandwidth and that's what 8VSB is. In actual fact, most modern 8VSB modulators don't actually work that way. Instead, they directly synthesize the equivalent waveform instead, but the net result is the same. The symbol rate of 8VSB is about 10 megabaud. And this is fundamentally why 8VSB is vulnerable to problems with multipath. There are 10 million symbols per second, meaning that the sample interval is only 100 microseconds long. In general, the shorter the sample interval is, the tighter the tolerances are.

QAM stands for Quadrature Amplitude Modulation. With QAM, you take a carrier and amplitude modulate it and phase modulate it at the same time. It's thus a combination of AM and FM that happen simultaneously. As with 8VSB, there is a sampling rate when the receiver must determine where in two dimensions the signal exists. In general, there are 2^n different amplitude and phase shift values in a "square" QAM constellation that has n different points on each axis, which yields n bits per baud. The more complex the constellation, the lower the symbol rate can go for the same bit rate. But the more complex the constellation, the higher your requirements for S/N become so that you can distinguish the different points from each other. Most cable companies run QAM-256, which is quite a complex constellation - each point encodes 8 bits of data. They can get away with 38 MB/s in a 6 MHz channel because of the lack of multipath and the high S/N ratio typical of cable delivery. You can run QAM over the air, but you would typically do so with only a 16 point constellation, which would net you a much lower channel bit rate than QAM-256, all else being equal. That said, if you were to attempt QAM-16 at ATSC's 19 MB/s data rate, the baud rate would be lower than 8VSB because each baud encodes 4 bits of data instead of only 3.

You might ask about 8VSB and its "constellation." With 8VSB only the amplitude of the signal is used to encode information. By coercing the waveform into a narrow bandwidth, we must give up any semblance of control over the signal's phase. As a result, when plotted on a constellation display, 8VSB's constellation consists of 8 vertical lines. Thus, each baud contributes 3 bits of information, which is why the baud rate of 8VSB must be so high. In theory, you could reduce both the baud rate of 8VSB and the width of the Nyquist filter at the same time, but doing so would make for a mode that wouldn't be compliant with ATSC specifications. By contrast, the DVB specifications incorporate many different modulation schemes, going all the way from 5 to 8 MHz wide.

The third method for delivering bulk digital data over RF is OFDM. OFDM stands for Orthogonal Frequency-Division Multiplexing. OFDM is a divide-and-conquer scheme. The incoming datastream is divided amongst a number of relatively closely spaced RF channels, each of which is either sent with traditional Phase Shift Keying or perhaps a low constellation QAM mode (PSK, however, at its heart is simply a variant of QAM - without any information on the amplitude axis). Because each individual carrier only has a small portion of the data, the resulting baud rate for each carrier is quite low. It does, however, complicate the receiver quite a bit, because it has to be able to receive and decode a number of digital streams in parallel. This is actually less of a big deal than it might seem, however, since it is relatively routine for multiple receivers to operate within a single chip. For example, there exist single-chip multichannel GPS receivers. And, of course, multiple methods exist to synthesize an OFDM "fugue," so to speak. The big downside of OFDM, however, is in its transmitter linearity and overhead requirements (particularly because of its much higher peak-to-average ratio), and its increased S/N requirements for receivers.

Tuesday, November 18, 2008

33 cm amp arrived

The 900 MHz amp I got the sweetheart deal on has arrived.

It's actually two amps, in fact.

The big one only has about 37 dB of gain. My thinking at the time was that its output at maximum input would not be sufficient for my needs. But now, my thinking has changed. If I feed the thing the maximum power from the exciter of 12 dBm average, the output power would be 79 watts average. Well, as we now know, the peak-to-average ratio of ATSC is 5 dB (at least it is 98% of the time), so that's actually 250 watts peak, which is probably too much (we'll have to get the thing on a scope to see for sure).

I bought that amp, plus a companion amp designed to boost the signal from -2 dBm to up to 5 watts. But I think, in retrospect, that given what I've learned that I'll probably just run the big amp by itself.

The first stage amp does have the advantage of having a power control pin that can be used to reduce the gain, but the exciter also has software output power control.

One thing that the big amp lacks is a PTT line (that is, something that can key the bias voltage for the modules on and off). This is something I'll likely need to add myself. The kind folks at the factory said they'd be happy to help with that when I got to that point.

It also lacks a cover. I'll need to get some sheet metal bent somewhere to fix that.

First step, however, will be trying it out on the air. But that will have to wait for a 28 volt power supply.

I'd like to publicly thank Ken and Lance - you two know who you are. I'd mention the company name, but I am not sure whether they would appreciate the publicity or not. If they would like a plug, I'll edit this post and add one happily. They are very nice people to deal with.

909 or 910?

I spent some time before work this morning pondering what to do about M-LMS licensees in the 33 cm band. M-LMS is the Multilateration Location and Monitoring Service. In the 90s, the FCC held an auction to grant nationwide licenses for this service. In the meantime, the growth of GPS has made the whole thing largely moot. Still, we amateurs must not cause harmful interference to them, to the extent that they actually use their licenses. The sooner those licenses are revoked, the better, I think, as there clearly is no public benefit to them.

There is a block of L-MLS allocation that ends at 909.75 MHz. If the last 750 kHz of this grant are in use, then I will have to change from 909-915 to 910-916 MHz. Fortunately, this is still a reasonable choice. On the TVC-9S, it's channel 2 instead of channel 1.

The only issue is the NARCC band plan for 33 cm, such as it exists. That band plan has ATV at 909-915 and a digital allocation at 915-917.

This doesn't really square all that well with the reality on the ground, given that potentially the range between 904 and 909.75 Mhz is the M-LMS block A allocation.

The NARCC plan also has an ATV channel on 922-928 MHz, which means it overlays the repeater output band at 927-928 MHz. That doesn't make sense.

The Mt. Diablo ATV folks have a repeater output from 918-924 MHz. This makes sense.

What would make sense in addition would be for NARCC to move the digital sub band from 915-917 to 916-918 MHz, move the lower ATV channel from 909-915 to 910-916 MHz, and recognize the reality that M-LMS probably denies us access to 904-910 MHz.

What am I going to do?

Well, it rather depends on whether there are current digital users between 915 and 916 MHz here in the Bay Area and/or the M-LMS license holder is actively using 909.0-909.75 MHz.

I can only hope and pray that both aren't true. If they are, then I will have no choice but to operate on 910-916 (since I can't interfere with M-LMS) or share 918-924 with Mt. Diablo. Both of those options would likely suck.

Monday, November 17, 2008

Legality of amateur ATSC

Just to dot the eyes and cross the Ts....

97.305(c) lists on a per-band basis the parts of 97.307(f) that apply. 97.307(f)(8) applies to all amateur allocations above 51 MHz (except for the 219-220 MHz 1.25m sub-band). 97.307(f)(8) says,

(8) A RTTY or data emission having designators with A, B, C, D, E, F, G, H, J or R as the first symbol; 1, 2, 7 or 9 as the second symbol; and D or W as the third symbol is also authorized.


The emission designator for ATSC DTV is C7W. That is, it is a vestigial sideband modulation (C), two or more digital channels (7), and a combination of different information (W). That means that, according to 97.307(f)(8) ATSC is allowed. Of course the lowest band where even a single ATSC channel would actually fit is the 70 cm band, so it is unusable on 6m, 2m and 1.25m.

The full designator for ATSC is 5M38C7WWT - the 5M38 indicates that the bandwidth is 5.38 MHz (though the channel is 6 MHz wide, there are 300 kHz of guard band at each end of the channel). The last W indicates a combination of video and audio and the last T indicates that the multiplex is via time-division.

How far?

One of the questions I hope to answer through testing is how far the signal will go.

As a starting point, there's this chart from PC Electronics (go to the end of the 2nd page).

To use this chart, you pick the diagonal line closest to the ERP of the transmitter. In the case of my test next Saturday, I'll be using 50 watts ERP, so you'd pick the 20 watt line. Next, you need to determine the delta between the real ERP and the power of the diagonal line in question. In my case, 50 watts is 3.9 db up, so you can round that up to 4 dB. Next, take the gain of your receive antenna. Let's say, just for the sake of argument, that you have a typical 5 dBd mobile whip antenna. Add 4 dB to 5 dB and you get 9 dB. Now, follow the 20W line on the chart over to where it touches 9 dB. The answer is about 18 miles. That's about how far away from Redwood City is from Mt. San Bruno. So if I was transmitting analog ATV with 50 watts of power (remember, that's *peak* power at sync), then you'd get a P5 picture in Redwood City, assuming that your mobile whip antenna had a line of sight to the mountain.

Of course, as we've discussed, power in ATSC is measured as average power, not peak. The broadcasters are using about 7 dB less power to cover the same service area, but that's peak NTSC vs average ATSC. In fact, the true PEP of ATSC is 7 dB above its average - which is coincidently the average delta around here between the analog and digital broadcasters. So I could say, with a straight face, that my 50 watts of ERP is actually 250 watts peak ERP. If you were to run that same exercise on 250 watts instead of 50 watts, you'd find that the range is off the chart - meaning that in real terms the range is limited by topography first. Is that really going to be the case with amateur ATSC? I rather doubt it. But one of the things we need to do is establish the ATSC equivalent to that chart - that is, to determine exactly what our coverage is with a given power level. And if we get a reception report from Blossom Hill or Los Gatos, well, that'll be a pleasant surprise.

Yes, it's the wrong band, but you can compare coverage for 900 MHz by simply subtracting 6 dB from the transmit ERP and using the same chart, as the accompanying text says. It looks like the new target average power output from the 33 cm transmitter will be 75 watts. That's 1.2 dB down from 100 watts. Add that to 6 dB for comparing 70cm to 33cm and you wind up with almost exactly the same number as the KP-20's antenna gain. So the 100W line on that chart will show range for P5 LOS DX with the receive antenna gain being the number you look up on the left side axis. So if you also use a KP-20, you'll find that you should be able to receive from about 30 miles away. This does, however, presume quite a lot: That P5 DX is equivalent to ATSC DX despite any part 15 QRM on the band.

Test next Saturday

Next Saturday, I'll be making the treck up to Mt. San Bruno for my first test transmissions at 420-426 MHz with ~50W ERP, commencing at 1:30 PM (these tests will start on the half-hour so they don't run into the 10 minute ID slide beacon from K6BEN/R). It'll probably last a half hour or so, barring equipment problems. I won't be running on 33 cm because I don't yet have an amp.

Once again, to receive, you'll need either a computer tuner like an HD Homerun that can tune 420-426 MHz without help or you'll need a standard ATSC TV or tuner connected to a downconverter like the PC Electronics TVC-4S (tuned to channel #1). If you try tuning it in, please be sure to drop a comment regardless of whether you got anything or not. Part of the purpose of these tests is to see how far it can go.

I'll see if I can borrow a 2M HT to take with me. If I can find one, I'll hang out on WB6OQS/R (146.76(-), PL 151.44).

I won't need any help up on the mountain - I'd rather people help by trying to receive the signal. Even if you can't actually decode it, if you can look for it with a spectrum analyzer, that would help. If you attempt to look for it with an analog TV, you'll just see white noise that's difficult (if not impossible) to distinguish from the noise floor.

Aside from PC Electronics, you can find downconverters at North Country Radio, but theirs is tuned with a potentiometer, rather than a PLL, so I'm not sure if frequency stability would be an issue for an 8VSB tuner.

If you are using an HD Homerun, you can use hdhomerun_config to set /tuner0/channel to 8vsb:423000000. No downconverter necessary.

More ATSC vs DVB-T arguments

This article at Broadcast Engineering is from a while ago (October, 2000), but it is another interesting point in the argument of whether 8VSB or DVB-T (COFDM) is better for amateurs.

In short, the peak-to-average ratio for COFDM is at least 2 dB greater, and the receiver needs about 4 dB more signal to receive. In other words, you need to pump out 6 dB more signal for the same coverage - that's 4 times more power. The article also mentions that COFDM is more sensitive to QRM than 8VSB. In the past, 8VSB used to have a harder time with multipath, but modern receiver chipsets have come a long way in ghost cancellation, and have largely caught up with their COFDM counterparts.

The reason we have a different standard of broadcasting than the Europeans do is due to the very different nature of broadcasting in Europe. In general, in the different countries in Europe, they have a relatively small number of broadcasters that have nationwide coverage. It would be as if NBC, CBS, ABC, Fox and PBS all had one channel that was replicated across the entire country with no local programming of any kind. The broadcasters in a particular country serve the whole country with multiple transmitters, obviously. With the advent of DVB-T, design decisions were made (by picking COFDM) that allow for multiple transmitters to operate on the same channel without interfering with each other - a so-called single frequency network (it's not really a single frequency as much as a single channel, but that's just a minor detail). Here in the US, Each individual broadcaster has a single transmitter (yes, some of them have translators, but those are special cases), and those single transmitters cover a much, much wider area than the individual transmitters in Europe. For US broadcasters, the higher peak-to-average penalty and the reduced range of power of COFDM would have been a bitter pill to swallow - particularly given the fact that broadcasters here actually pay for the spectrum rather than getting handouts from the government. Given the different reality of how broadcasting works here, it's no surprise that the FCC chose 8VSB.

I mean, to my mind, it's still moot: If the North American market had thousands and thousands of COFDM receivers, then that's what I'd be planning to use. The decision to go with 8VSB in the broadcasting universe was, for us amateurs at least, serendipitous.

ATSC peak to average - straight from the horse's mouth

These guys are in the business, they ought to know. This article in Broadcast Engineering talks about ATSC peak-to-average ratios. I was wrong to merely assume that the 3 dB ratio between average and the top symbol was all that was involved. There is overshoot all the way to 7 dB - 5 times the average power. However, look at Figure 3 in that article - the peaks are present only for very brief instances - the signal spends less than 2% of its time above 5 dB, which is triple the average. That does explain why the 10 watt picture of my 7025PA doesn't look as pretty is the 6 watt picture. At 6 watts, the peaks are entirely within 30 watts, which is almost entirely within the amp's linear range. However, at 10 watts, we're going to exceed the 30 watt number 2% of the time, meaning that those peaks almost certainly will be clipped, which is why the skirts start to grow.

This puts the impending arrival of the 200W amp in a different perspective. 200/3 = 66 watts, which is likely what I'll be able to get out of the thing and still be reasonably clean. It may have more headroom above 200W. If it could make it to 250W without clipping, then that would be 83 watts, but I still think I'd be happy with 66. That's 330 watts ERP.

Sunday, November 16, 2008

Meanwhile, in analog land...

I'd like to publicly thank Brian, KT6LN, for loaning me his Bird wattmeter. It confirmed that I am getting about 17 watts of power out of my DEMI 2330PATV and, more importantly, there is no reflected power. So I am getting probably about 300W ERP into K6BEN/R. It's actually been working lately, though the video doesn't look amazing, and I'm not completely knocking down the FAA RADAR QRM like some of the stronger uplinks do.

I was also able to use his wattmeter to confirm the output of the 70 cm amplifier on ATSC, though the issue there is that not all of the power coming out of the amp is actually useful signal, if you're not careful.

My experience with ATSC makes me wonder whether part of that 17 watts is out-of-channel crap that isn't contributing anything useful to my receive signal at the repeater. But this is FM TV we're talking about. Even a class C amp should be fine.

I also am not getting a P5 picture back down from the repeater. I'd say it's P4.5 or so. I suppose some of the imperfection I'm seeing is on the downlink side. I am, however, happy to just get in.

Site survey suckage

So, the roads up to Mt. Chual and Loma Prieta are tres suck. Not only are they mostly dirt roads once you get close to the summit, but they run up the back of the mountain up to locked gates, so even if you stop short of the summit, you have no exposure to the valley.

Driving along Skyline from highway 17 to Page Mill Road is no better. But it looks like there is a road running up to the summit of Black Mountain. The Longley-Rice analysis for 50 watts ERP of 423 MHz from up there looks pretty decent. Maybe that will be a good place for the test transmission(s).


ATSC peak-to-average

So I may be realizing that the peak-to-average ratio of ATSC may actually be closer to 5 dB rather than 3 dB. It is true that the maximum actual amplitude sampling point is 3 dB above average, but the signal over-swings beyond that, and attempting to clip it just forces the out-of-channel sidebands up.

In these views, the reference level is actually 20 db higher than listed, because there is a 20 dB attenuator on the input to the SA.



That's the output of the amplifier at minimum driver power - which results in about 6-7 watts of channel average power output. The skits that are visible at about -25 dBm were present in the output from the exciter, but were slightly lower (maybe 5 dB) relative to the main signal.



That's the output at one notch up from the minimum - which is about 10-12 watts of average power or so, but it's a bit uglier.

Saturday, November 15, 2008

Ready for 420

The DEMI 7025PA kit arrived yesterday and I took it to work with me and assembled it after work. I'm really bad at surface mount stuff, but I managed to get the thing together without any undue issues.

I assembled the amp without any changes in bias (they include some extra resistors you can use to reduce the bias voltage if you want), and without the load resistor on the input (to maximize the sensitivity). The amp is unbelievably sensitive in this configuration. Turning the power up past 4 (on a scale of 1 to 15) saturates the amp (that is, starts increasing the out-of-channel skirts without appreciably boosting the amplitude of the main signal). But so far as I can tell, I'm still getting about 10 watts of channel average power, or 20W PEP (remember, the peak-to-average ratio for 8VSB is 3 dB).

Even at minimum power, the out-of-channel skirts are a bit higher than I would like to see, but it's nothing that a mask filter can't fix, if I were going to run on 70 cm a non-trivial percentage of the time.

Tuesday, November 11, 2008

Mischief managed

I got the replacement MMIC and ferrite bead yesterday for the exciter, and a coworker was kind enough to help me out with the surface mount surgery. After it was done, with the test equipment on the bench, we measured a total channel power of 12 dBm, or 15 mW.

Monday, November 10, 2008

Overall repeater design

So I am not sure I've gone through in detail all of the parts that have to come together...

To just go up on top of a hill and transmit DTV is one thing, but again, the goal here is a repeater.

Pieces still needed:

The final amplifier. I have a line on a 100W model, which would be a boost compared to the DEMI 70W (which I'll be fortunate to get 40W and still have it be linear). 100W into the KP-20 I have would be half a kilowatt ERP! From Mt. Chual, that would almost certainly blanket the south bay nicely.

But it will need a 28 VDC power supply, and I'll then need a 28-12 volt DC-DC converter (@ 1A) to power the rest of the gear.

I'll be needing to place another order with SR-Systems - this time for a 4:1 TS MUX, another MPEG encoder and a DVB-T receiver for 426-431 MHz.

A 2 meter NBFM receiver for a 2 meter talk-in / control channel

A tower camera

A 1.2 GHz FM TV receiver

A Diamond X-6000 receive antenna and a 3 port duplexer (2m, 70 cm, 23 cm).

And lastly, I will need to build a repeater controller. For this, I'll use an Intuitive Circuits OSD generator, a Javelin Stamp, a DTMF decoder (for control) and a 567 wired as a horizontal sync detector (to detect video input from the FM receiver). I'll use the Javelin's UART class to bit-bang serial output to the OSD, another output pin as a PTT control line (which really will just key the amplifier - the exciter will free-run so as to reduce latency), and two pins as video-good input signals - one from the 567 for the analog video input, and the other from the DVB-T receiver.

The whole thing will probably draw about 600 watts of AC power while transmitting.

Sunday, November 9, 2008

Stupid Blackberry ad



The ad asks, "What kind of mad genius is behind this?"

I believe his name is Steve Jobs.

I want one of THESE

This looks like it would be the perfect amp for the repeater. Derating the output down to 100 watts would insure that it was being driven entirely within its linear range, and besides the Comet KP-20 antenna I have has a maximum power rating of 100 watts.

The difficult part is that it requires a 28 volt power supply. DuraComm makes one, but then I'll need a DC-DC converter to come up with the 12 volts to run everything else.

Saturday, November 8, 2008

Range experiments

I bought a 1/4 wave vertical at HRO today with a mag mount for the car. Yes, I should have got something with some gain instead, but I decided to go cheap. Eventually I'll buy a Diamond X-6000 for the receive antenna for the repeater, but not this week.

I hooked the transmitter up to the UHF antenna on the corner of the garage (A Diamond V2000, which has 8.4 dB gain on 430 MHz). I measured the transmitter as best I could on the SA and it seems to be generating about 5 dBm or so. With some feedline loss, I'll assume that the net gain of the antenna system is 8 dB, so that gives us a total of 13 dBm - 20 mW ERP.

I put the 1/4 wave vertical on the van, grabbed the 70 cm downconverter and the Insignia TV and went for a drive.... to the end of the block. Google Earth says that over flat ground, I got a maximum range of about 190 meters. I probably could have shouted that far.

So the distance record for amateur ATSC TV at the moment stands at just shy of two football fields.

The amplifier is coming.... someday....

Friday, November 7, 2008

Receiver compatibility list

One thing that will have to be done will be to keep a list of consumer grade ATSC receivers with notes on how well they work (or don't) with the output of the Minimod. I'll try to keep an up-to-date listing here.

Some receivers that can't process MPEG audio themselves sometimes pass the audio out to an S/PDIF port, which gives you a 2nd chance to decode it. This assumes, of course, that your tuner has one of those. Coupon Eligible boxes won't.

In general, tuners intended to work with computers will likely work perfectly, as they simply extract the transport stream from the 8VSB channel and expect the computer to decode it in software. Videolan should have no trouble, so long as it supports your device. Software that comes with the tuners should generally work as well. One big exception is EyeTV. When I've manually tuned the HDHomerun to the transmitter output, EyeTV has simply said that nothing was there. It's possible that EyeTV is insisting on finding the PSIP tables, but I haven't really dug into the problem to figure out what's wrong. I've simply used hdhomerun_config (downloadable from Silicon Dust) to capture the stream and MPEG Streamclip to convert it.

Unless it's otherwise mentioned, all of the tuners listed will need a downconverter for any ham band.

Silicon Dust HD Homerun: works perfectly, and can tune 70cm frequencies without a downconverter.

Samsung SIR-T451: Video good, no audio. I haven't tried the S/PDIF port.

Insignia NS-7HTV LCD TV: Video and audio both work.

Samsung LN-T4069F LCD TV: Video and audio both work.

Insignia NS-DXA1: Video good, no audio.

Obviously, I can't really ask people for reports with their own receivers yet, since I can only put out a couple of mW of power. But once I can get a significant amount of power out, I'd like to hear from owners of as many different receivers as possible to expand on this list.

Thursday, November 6, 2008

QSY...

Well, it turns out the output of the Mt. Diablo ATV repeater is on 919.25 MHz, so a change of frequency is in order. We'll be using 909-915 MHz. This lines up with channel 1 on the TVC-9S downconverter. It's conceivable that there would not be any interference between the Mt. Diablo repeater and ours, but there isn't anything else around here listed on the NARCC website on 910.25 MHz (which is 909-915 MHz), so there's no reason not to change. In fact, the only thing listed on that frequency is a repeater input in Springville, Northeast of Bakersfield.

So a little edit. Subtract 9 MHz from all of the 33 cm frequencies I've mentioned so far. :)

Successful end-to-end test at 918 MHz



I got a PC Electronics TVC-9S 33 cm ATV downconverter yesterday and this evening I was able to conduct a complete end-to-end test at 918 MHz. I got a little rubber-duck 900 MHz antenna for the downconverter and fed the transmitter into a Comet KP-20. I had to turn the transmitter power down to minimum, but doing so allowed the HD Homerun to capture the stream without any errors. Not only that, but I was able to plug the downconverter into my little insignia portable LCD digital TV, and that little TV not only was able to show the picture, but the sound worked too!

Livin' the dream

Ok, Democrats. You're in the driver's seat now. You guys said that you'd make it all better. And now, you've got no excuses and no one to blame but yourselves if in 4 years time we're not in Ronald Regan like nirvanha.

In fact, the comparisons are pretty apt. The country was in bad shape, both at home and abroad at the end of Jimmy Carter's term as president. The country voted for change with both feet and elected Ronald Regan. He presided over the biggest peacetime economic expansion the country has ever known, and over the demise of soviet communism. Well, at the end of the Bush presidency, the country's in the shitter again, and the country has voted for change once again with both feet and elected Barack Obama. It will be interesting to see where we are 4 and 8 years hence in comparison to where we were in 1984 and 1988 relative to 1980.

I think either way it'll be telling. If things do improve, then it proves that the republicans and democrats really are highpopalorum and lowpopahighram, just like Huey P. Long said they were. If things don't improve, then I'll look back and say, "See? They said that if I voted for John McCain, the country would still be in the shitter and they were right: I voted for John McCain, and the country is still in the shitter." (with appologies to the old saying about Goldwater and the Vietnam war).

Wednesday, November 5, 2008

Measuring ATSC power

I've been measuring the power from my ATSC transmitter by looking at its output on my spectrum analyzer. It turns out, however, that that probably is not an accurate way to judge the transmit power.

I found a PDF that has an explanation.

A spectrum analyzer is a radio receiver, whose output is hooked up to the Y axis of an oscilloscope. The X axis is a sawtooth wave, like a normal oscilloscope, but in addition to sweeping the X axis of the display, it also adjusts the frequency of the receiver.

There's a bit more to it than that, however.

One of the characteristics of the radio receiver that's part of a spectrum analyzer is its "Resolution Bandwidth." This is the bandwidth of the receiver. That is, in order to plot an amplitude value on the display, how wide of a swath of the RF spectrum do you sample in order to determine what that amplitude is?

The resolution bandwidth of a SA is tied to the span of the display. The larger the span, the higher the resolution bandwidth, which means the wider a signal has to be to actually show up. At the same time, the smaller the resolution bandwidth, the slower the sweep has to be in order to display the finer grained samples.

If the signal you're watching fits inside of the resolution bandwidth, then the entire signal contributes to the amplitude that shows up on the display. But if the signal is wider than the resolution bandwidth, then at any one given moment, you're only plotting a fraction of the signal's power on the display.

It turns out that if you know the 3 dB bandwidth of the signal (for ATSC it's 5.83 MHz), and the RBW of the SA, then you can calculate a correction factor: 10 * log (RBW / Signal BW) dB is how far down your SA will show the signal. That is, you subtract that number (which is probably negative) from the displayed power level to obtain the real one.

I took a picture the other day that showed my transmitter's signal at the 2nd division down from the top, and the reference level was -4 dBm, with 10 dB per division. That's a signal strength of -14 dBm. But the RBW was 100 kHz, so the correction factor is -17.65 dB, which actually put my output power at +3.65 dBm, or about 2.3 mW.

Sunday, November 2, 2008

Save the date: 2/14/09

DATV or bust.

February 14th, 2009 at high noon, I will be transmitting ATSC (or as close as I can get to it) with as much power as I can muster at 918-924 MHz from the summit of Mt. San Bruno. If equipment and time permit, I will also attempt to transmit on 420-426 MHz. This date in particular was chosen because it is the last saturday before Feb 17th, the date of the broadcast TV analog shut-down.

The plan is to generate about 150 watts of ERP at 918 MHz, and if I can obtain an amp in time, perhaps as much as 100 watts of ERP at 420 MHz.

The 73 cm transmissions should be receivable using a stock Silicon Dust HD HomeRun. You may need to direct it with the hdhomerun_config command to receive 8vsb at 423 MHz, since that's not a standard broadcast frequency.

The 33 cm transmissions will likely require use of a downconverter in front of an ATSC tuner. The PC Electronics TVC-9S set for channel 4 should work just fine combined with an ATSC tuner set for channel 3.

Those using computer connected tuners should have no trouble decoding the transport stream, while those using TV sets or consumer grade tuners may be limited to video only, as the audio will be MPEG audio rather than Dolby AC3 (which is required by the ATSC spec).

Please spread the news as far and as wide as possible. I'm setting this date this far in advance in the hopes of it becoming a highly anticipated event in the amateur community.

Boosting the power

I heard back from Stefan at SR-Systems today. He said that if I replaced the MMIC on the minimod with a GVA 84+, and the bias inductor with a 600Ω 3A ferrite bead, that would boost the output by 12 dB. That would be enough, I think, to get us at or near 0 dBm, at least as measured by my spectrum analyzer (Stefan says I should actually expect to get -1 dBm now and close to 10 dBm after replacing the MMIC, but I think he's measuring the power by having the board transmit a CW carrier rather than measuring the power of the actual modulated digital signal).

I've gone ahead and ordered one of those MMICs. I'm not confident enough of my surface mount soldering techniques to work on a kilo-Euro worth of equipment, but I have some hopes that I'll be able to enlist someone in the hardware lab at the office to help me.

I also hope that the hardware lab can spare the ferrite bead. I think it's silly to try and order a single quantity surface mount component mail order. I bought a 20 dB attenuator in the same order as the single MMIC just to make the shipping costs worthwhile. With the attenuator, I should be able to run the output of my amp directly into the SA for power measurements and stuff (the SA can take up to 30 dBm - 1 watt - of input power).

One more ATSC video



Here you can actually see the gear, plus I captured some video of the transmission on a spectrum analyzer.

Saturday, November 1, 2008

Amateur ATSC and consumer tuner compatibility

One of the big questions about all of this is whether or not the output of this system would actually be receivable on consumer ATSC tuners.

Well, it is conceivable that someone could tune this gear up on UHF TV channel 16, but it would be a shocking violation of FCC rules to do so. Nevertheless, if someone were to attempt something so foolish with a tenth of a milliwatt, and attempt to receive it with, say, a Samsung SIR-T451, they'd find that it actually would show a picture! Unfortunately, the audio wouldn't work, since it's MPEG 2 audio instead of Dolby AC3, but the picture would decode properly despite the lack of proper PSIP and despite the audio being the wrong codec.

For what that's worth.

Another ATSC recording



This time, I'm on camera.

More DATV success!



I was able to use MPEG Streamclip to export the video and audio from my first captured ATSC transmission this afternoon and upload the result to YouTube!

I suspect that there are still some tweaks necessary for full HDHomerun compatibility - for one thing, I haven't yet gotten EyeTV to actually bring up the video yet. Probably has to do with the PSIP tables (or lack thereof?). I suspect a firmware upgrade may be forthcoming. :)

First ATSC transmission from N6QQQ!

I hooked up the stuff I got from Germany today and set it up... And it appears to work perfectly! In fact, the output waveform looks exceptionally clean - just like a real broadcaster! We'll have to see what happens after it gets run through an amp, of course...

The output is -10 dBm, which is less than I had hoped. I will need to boost that, somehow, before feeding it into a DEMI amp. But even so, it was enough to set it running at 420-426 MHz, feed it to my UHF vertical and receive it on the broadcast TV system at -60 dBm! Not only that, but the HDHomeRun actually was able to save the transport stream!

That, unfortunately, is where the good news stops. I don't have the software tools handy to decode that transport stream, probably because I didn't make any attempt to filter the transport stream by program ID or anything.

Forgotten old movie tech

Last night, Scarlet and I went to Davies Symphony Hall and watched the 1925 film "The Phantom of the Opera" (starring Lon Chaney) with the original accompaniment score performed on solo organ (and Foley board) by Dennis James. Mr. James played the renowned Ruffati organ installed in Davies 25 years ago this year. It is the largest concert hall organ in North America. It was a spectacular evening, but the real highlight for me was a re-introduction to early motion picture technology.

Advances in the state of the art in any field always obsolete prior technology, resulting in the loss of specialized techniques used to optimize the technology of the time. Case in point: the iambic keyer. It represents the state of the art in optimizing the transmission of morse code. Morse code is an obsolete technology, relegated largely to the amateur radio bands nowadays. With the advent of satellite based search and rescue beacon technology, the last non-amateur use for morse code (namely the maritime service) has gone by the wayside. Apart from Amateurs, nobody therefore has a use for an iambic keyer. And I think it won't be too long before you'll need to go to a museum to see an Iambic keyer - the furthest development of a technological cul-de-sac.

Thus is it with film. When we think of early films, we think of black-and-white silent films. We think of that because we're used to television, and before color television, TV was itself monochromatic (black-and-white is a misnomer: both TV and film offer a continuous greyscale). But, as I discovered last night, early cinema was not monochromatic. Early TV was monochrome because the actual color that the viewer saw depended on the color of the phosphors that were built into his own TV set. Thus, everybody saw exactly one color - which tried to be as close to a neutral grey as possible.

This was not the case for film, however. While the actual photographic process was greyscale, the film stock itself could be tinted. Within the single film we saw last night, I counted at least 3 different film-stock tints. These differing tints were used by the film's creators to change the tone of the scenes. This is something that was impossible for television before the advent of full color broadcasting in the 1960s. When you saw a film on TV, it was greyscale, period (unless you put colored films or other such trickery in front of the tube).

Not only that, but certain scenes in the film we saw last night were actually in full Technicolor! Color photography was in its infancy in the 1920s. It was nightmarishly expensive, but it could be done. In addition, it was possible for much less money to highlight a single color - the Phantom's red cape, for instance - in a particular scene. This was also done in the film we saw last night.

In addition, it was not unheard of for some filmmakers to have certain elements of their films hand tinted. An example of this is still preserved today in the Chriterion Collection edition of Jacques Tati's film Jour de Fête, where the french flag is tinted red and blue.

Lastly, before the advent of synchronized soundtracks, it was customary for the projection frame rate for films to be variable. Usually, instructions were provided to the projectionist along with the reels of film for what speed various scenes were to be shown. Sometimes the projectionist would ignore those instructions and do whatever they felt was right (or perhaps they were just lazy and set one speed at the start). Because of that, individual experiences in viewing a single film could actually vary. Essentially, there is a tradeoff between slower speeds that flicker a bit less and use less feet-per-minute of film, versus faster speeds that make fast action less blurry.

With the advent of synchronized soundtracks, it was necessary to stick with a standardized frame rate (the industry chose 24 fps) to insure that the pitch of the sound didn't vary, but at the same time, one of the tools used for decades to customize the performance was lost.

With modern digital video technology, resolution and frame rate are, once again, adjustable. There's nothing that would prevent someone from varying the frame rate by scene. But the problem is that it likely wouldn't do any good, since most displays simply adapt the incoming material's frame rate to the native refresh rate of the display. Making matters worse, some displays either do a lousy job of this, or fail if faced with non-standard refresh rates. For instance, most cartoons are animated at only a maximum rate of 12 fps (with adjacent frames of 24 fps film being identical), and that's only during action sequences. The reason for this is the enormous cost of animation. It would make sense, therefore, to MPEG encode such cartoons at 12 fps. But this typically isn't done. Instead, the encoding is done at 24 FPS and redundant, empty I frames are sent in the extra time.

With the advent of television and full color movies, these techniques were rendered obsolete. In the case of television, the viewer could only see monochrome anyway, and in the case of movies, full color made the other tricks unnecessary. It is only in experiencing what must be characterized as an early cinema museum performance that we in the audience were privileged to get a glimpse of the highest state of the art of early cinema.

Saturday, October 25, 2008

What do YOU do?

This sort of thing happens far, far, far too often.

This is a scheduled MTT. 125 folks are vying for 27 prizes. That's right - one chance in three.

What? I bought in before I figured that out. :)

Anyway, let's take a look at this hand:

Full Tilt Poker Game #_: $75 Token Frenzy (_), Table 5 - 20/40 - No Limit Hold'em - 16:55:20 ET - 2008/10/25
Seat 1: (1,290)
Seat 2: (1,950)
Seat 3: (1,770)
Seat 4: (1,395)
Seat 5: (1,440)
Seat 6: (1,375)
Seat 7: (5,245)
Seat 8: hero (1,560)
Seat 9: (1,835)
Seat 9 posts the small blind of 20
Seat 1 posts the big blind of 40
The button is in seat #8
*** HOLE CARDS ***
Dealt to hero [Ts 4c]
Seat 2 folds
Seat 3 folds
Seat 4 folds
Seat 5 raises to 1,440, and is all in
Seat 6 folds
Seat 7 folds
hero folds
Seat 9 folds
Seat 1 calls 1,250, and is all in
Seat 5 shows [7c 7s]
Seat 1 shows [Qh Ah]
Uncalled bet of 150 returned to Seat 5
*** FLOP *** [As Js Kc]
*** TURN *** [As Js Kc] [4d]
*** RIVER *** [As Js Kc 4d] [7d]
Seat 5 shows three of a kind, Sevens
Seat 1 shows a pair of Aces
Seat 5 wins the pot (2,600) with three of a kind, Sevens
Seat 1 stands up
*** SUMMARY ***
Total pot 2,600 | Rake 0
Board: [As Js Kc 4d 7d]
Seat 1: (big blind) showed [Qh Ah] and lost with a pair of Aces
Seat 2: didn't bet (folded)
Seat 3: didn't bet (folded)
Seat 4: didn't bet (folded)
Seat 5: showed [7c 7s] and won (2,600) with three of a kind, Sevens
Seat 6: didn't bet (folded)
Seat 7: didn't bet (folded)
Seat 8: hero (button) didn't bet (folded)
Seat 9: (small blind) folded before the Flop

Come on now. You're seriously going to flip a coin with 7s (after all, with pocket 7s, you're likely at best a coin-flip against any hand that can call) on a tournament that's one-in-three? Really?

The big question here is, what do you do with AQ? It's for sure that the donkey opposite wouldn't bet 30 big blinds with a really premium hand. So you're either up against a weaker ace or a small pair or perhaps even dog crap. In other words, the AQ is at worst a coin flip.

But fundamentally, even though your opponent has forced you into a decision like that, I can see both sides. If it were a cash game, you'd be +EV to call, but this is a tournament. If you fold AQ in that spot, you do so only because you don't want to risk the entire tournament on a single early coin flip against a maniac.

How should that hand have gone?

The 7s should have either made a normal raise or limped with the expectation of ether flopping a set or folding. Whether you raise pre-flop or not depends on your playing style. The AQ would have either re-raised or called, depending on his playing style. The 7s would have flat-called the re-raise if it happened. The flop would have come and if there was no re-raise pre-flop, the 7s would have perhaps continuation-bet and the AQ raised, or the 7s would have checked and the AQ bet. The 7s would have folded and the AQ would have taken down a pot with maybe 300 chips in it, but both stacks lived to see the next hand.

Friday, October 24, 2008

M zone calculator

I actually made this little site to help someone else, but on the off chance that it is helpful, I'll let my other 5 or 6 readers check it out too. It's an "M zone" calculator. You can use it during a tournament (it is set up for Full Tilt and PokerStars SnG tournament structures) to figure out what M zone (basic and effective) your chip stack lies in.

Check it out.

Tuesday, October 21, 2008

Cold deck

I wasn't involved, and there's nothing really to be learned here, but you don't see this sort of thing every day.


Full Tilt Poker Game #_: $55 + $5 Sit & Go (Turbo) (_), Table 1 - 15/30 - No Limit Hold'em - 12:06:21 ET - 2008/10/21
Seat 1: (1,485)
Seat 2: (1,455)
Seat 3: (1,395)
Seat 4: hero (1,470)
Seat 5: (1,500)
Seat 6: (1,500)
Seat 7: (1,545)
Seat 8: (1,650)
Seat 9: (1,500)
hero posts the small blind of 15
Seat 5 posts the big blind of 30
The button is in seat #3
*** HOLE CARDS ***
Dealt to hero [4c Qc]
Seat 6 folds
Seat 7 folds
Seat 8 folds
Seat 9 folds
Seat 1 folds
Seat 2 raises to 90
Seat 3 folds
hero folds
Seat 5 raises to 180
Seat 2 calls 90
*** FLOP *** [8d Ad As]
Seat 5 checks
Seat 2 checks
*** TURN *** [8d Ad As] [Th]
Seat 5 bets 300
Seat 2 raises to 1,275, and is all in
Seat 5 calls 975
Seat 2 shows [Td Ts]
Seat 5 shows [Ac Ah]
*** RIVER *** [8d Ad As Th] [Tc]
Seat 2 shows four of a kind, Tens
Seat 5 shows four of a kind, Aces

And there you have it: quads over quads.

If this was a cash game at Lucky Chances, that would have been a bad beat jackpot.

Seat 5 wins the pot (2,925) with four of a kind, Aces
Seat 2 stands up
The blinds are now 20/40
*** SUMMARY ***
Total pot 2,925 | Rake 0
Board: [8d Ad As Th Tc]
Seat 1: didn't bet (folded)
Seat 2: showed [Td Ts] and lost with four of a kind, Tens
Seat 3: (button) didn't bet (folded)
Seat 4: hero (small blind) folded before the Flop
Seat 5: (big blind) showed [Ac Ah] and won (2,925) with four of a kind, Aces
Seat 6: didn't bet (folded)
Seat 7: didn't bet (folded)
Seat 8: didn't bet (folded)
Seat 9: didn't bet (folded)

Monday, October 20, 2008

Beat iPhone hold 'em



So that picture is what you get when you win the Dubai tournament. It's the same as the "winner" screen for all the other tournaments except for the prize amount. I've done this a few times now. It's really not too much trouble to beat the bots in the iPhone poker program. They don't really change any as you progress upwards through the tournaments.

I play with the phone in the landscape mode. In this mode, you can't watch the video of them to look for their "tells," but I find I can't easily follow the position very well with the portrait view. And position and relative stack size are more important anyway.

The biggest weakness of the bots is that they don't have any internal concept of being pot committed or of fold equity. They're quite content to bluff 75% of their stack and then fold to the re-raise. This makes the ideal strategy against them to be one of always raising and never calling. They will call you all-in with crap draws that would normally be very -EV plays (particularly in tournament play). Yes, occasionally those will suck out, but most of the time they won't. And once you cash, simply either fold or go all-in on every hand pre-flop (which alternative will obviously depend on the relative stack sizes in question and, of course, your cards).

Of course, all of this is sort of poker masturbation. In general, it's a bad idea to play against bots - particularly bad ones. The risk is that you'll pick up habits against the bots that don't work against real players (particularly good ones). But in this case, the ideal strategy isn't tremendously different from normal SnG strategy. You just need to crank the aggression factor up much, much higher than you normally would.

The payouts for the "two table" tournaments (that is, everything above the "Cruise Ship") have payouts that would be reasonably correct if they were actually 3 table shoot-outs, meaning that they take the top 3 finishers from 3 tables and sit them down at the final table (which means you actually had 27 opponents in the prize pool). I've never come across any real tournaments that do that (most shootouts take the 9 first place finishers from 9 single table tournaments and have them play a final table). The payouts for the single table tournaments (Cruise Ship and below) pay out at a much higher rate than they should (obviously the Garage game, being a free-roll, pays out fixed prizes simply as a bootstrap). Thus the ideal bankroll strategy is to play only up to Cruise Ship for as long as you can to build your bank. Then skip upwards only once you've got a lot of (fake) money. Once you have a couple hundred grand you can take a couple shots at Dubai and if one of them hits, you'll have plenty of bank to repeat and build from there.

Sunday, October 19, 2008

Oh, *I'M* the donkey?

After the hand, the guy called me out in the chat window, so he gets a public rebuttal. He took a chance on a deceptive play and it backfired on him. That's my fault somehow?

Let's see who made the bad play here.

Full Tilt Poker Game #_: $55 + $5 Sit & Go (Turbo) (_), Table 1 - 100/200 - No Limit Hold'em - 1:30:18 ET - 2008/10/20
Seat 1: (1,900)
Seat 2: (1,015)
Seat 3: (1,600)
Seat 4: (2,920)
Seat 6: villain (1,390)
Seat 7: hero (1,635)
Seat 8: (3,040)
Seat 8 posts the small blind of 100
Seat 1 posts the big blind of 200
The button is in seat #7
*** HOLE CARDS ***
Dealt to hero [5d 5c]
Seat 2 folds
Seat 3 calls 200
Seat 4 folds
villain calls 200
hero raises to 1,635, and is all in

1. The two limpers are unlikely to have better pairs since they didn't raise.

2. Because the blinds are so high here, any raise would be enough of my stack that I should just push anyway.

3. I have enough fold equity left to hopefully push these two off mediocre hands and pick up a nice pot.

Seat 8 folds
Seat 1 folds
Seat 3 folds
villain calls 1,190, and is all in
hero shows [5d 5c]
villain shows [Td Ts]

Really? Limping with tens? So you're ok letting a big blind see the flop for free with a big pair?

Now, don't get me wrong: I've done a limp-reraise play myself sometimes. But you pull that sort of play only against very aggressive players who have established a pattern of raising with junk. It's also a lot safer once you're actually in the money. Before the money, it's much, much better to win a small pot than lose a big one (which is really about the only two choices available to you with pocket tens).

Uncalled bet of 245 returned to hero
*** FLOP *** [5s 9c Kh]

So, yeah, I sucked out there. But what if the big blind had 59? You make a proper raise there and I guarantee that my 5s hit the muck before your chips stop moving. And if you get called by someone else I'll see that 5 come and I'll go kick my dog.

*** TURN *** [5s 9c Kh] [2s]
*** RIVER *** [5s 9c Kh 2s] [Ad]
hero shows three of a kind, Fives
villain shows a pair of Tens
hero wins the pot (3,280) with three of a kind, Fives
villain: lol pos

I agree: limping with tens is a very POS play, dumb-ass.

villain stands up
*** SUMMARY ***
Total pot 3,280 | Rake 0
Board: [5s 9c Kh 2s Ad]
Seat 1: (big blind) folded before the Flop
Seat 2: didn't bet (folded)
Seat 3: folded before the Flop
Seat 4: didn't bet (folded)
Seat 6: villain showed [Td Ts] and lost with a pair of Tens
Seat 7: hero (button) showed [5d 5c] and won (3,280) with three of a kind, Fives
Seat 8: (small blind) folded before the Flop

What does it take?

What the do I have to do to get retards to lay down their stupid flush draws? Go all-in on any flop with two of a suit?

Full Tilt Poker Game #_: Turbo Fiddy (_), Table 13 - 25/50 - No Limit Hold'em - 1:15:06 ET - 2008/10/20
Seat 2: (3,595)
Seat 3: (540)
Seat 4: (2,005)
Seat 5: hero (2,000)
Seat 6: (1,315)
Seat 7: villain (3,675)
Seat 8: (1,060)
Seat 9: (3,810)
Seat 4 posts the small blind of 25
hero posts the big blind of 50
The button is in seat #3
*** HOLE CARDS ***
Dealt to hero [Ad 6d]
Sear 6 folds
Seat 7 calls 50
Seat 8 folds
Seat 9 calls 50
Seat 2 folds
Seat 3 folds
Seat 4 folds
hero raises to 225
villain calls 175
Seat 9 folds
*** FLOP *** [As Qc 5c]
hero bets 525
villain calls 525
*** TURN *** [As Qc 5c] [Kd]
hero bets 1,250, and is all in
villain calls 1,250
hero shows [Ad 6d]
villain shows [2c 3c]

Really? You called a pre-flop raise and went all the way to the river with the worst flush draw possible?

You know, when they talk about licensing and regulating Internet poker, I often wonder if it's the sites they should really be licensing.

*** RIVER *** [As Qc 5c Kd] [8c]

Oh, of FUCKING course.

hero shows a pair of Aces
villain shows a flush, Queen high
villain wins the pot (4,075) with a flush, Queen high
hero stands up
The blinds are now 30/60
*** SUMMARY ***
Total pot 4,075 | Rake 0
Board: [As Qc 5c Kd 8c]
Seat 2: didn't bet (folded)
Seat 3: (button) didn't bet (folded)
Seat 4: (small blind) folded before the Flop
Seat 5: hero (big blind) showed [Ad 6d] and lost with a pair of Aces
Seat 6: didn't bet (folded)
Seat 7: villain showed [2c 3c] and won (4,075) with a flush, Queen high
Seat 8: didn't bet (folded)
Seat 9: folded before the Flop

There is nothing to say

Here's a two-fer from the same SnG:

First, try and guess what each of these two players has. You're going to be wrong. Promise.

PokerStars Game #_: Tournament #_, $50+$2 Hold'em No Limit - Level I (10/20) - 2008/10/19 3:05:13 ET
Table '_ 1' 10-max Seat #2 is the button
Seat 1: (1500 in chips)
Seat 2: donkey (1540 in chips)
Seat 3: (1460 in chips)
Seat 4: shark (1500 in chips)
Seat 5: (1500 in chips)
Seat 6: (1500 in chips)
Seat 7: (1500 in chips)
Seat 8: (1500 in chips)
Seat 9: hero (1500 in chips)
Seat 10: (1500 in chips)
Seat 3: posts small blind 10
shark: posts big blind 20
*** HOLE CARDS ***
Dealt to hero [7s 3s]
Seat 5: folds
Seat 6: folds
Seat 7: folds
Seat 8: folds
hero: folds
Seat 10: folds
Seat 1: folds
donkey: raises 20 to 40
Seat 3: folds
shark: raises 60 to 100
donkey: calls 60
*** FLOP *** [Qc Js 5d]
shark: bets 100
donkey: calls 100
*** TURN *** [Qc Js 5d] [Ah]
shark: bets 180
donkey: calls 180
*** RIVER *** [Qc Js 5d Ah] [4h]
shark: bets 500
donkey: raises 660 to 1160 and is all-in
shark: calls 620 and is all-in
Uncalled bet (40) returned to donkey
*** SHOW DOWN ***
donkey: shows [Ts 4s] (a pair of Fours)
shark: shows [As Ad] (three of a kind, Aces)
shark collected 3010 from pot
*** SUMMARY ***
Total pot 3010 | Rake 0
Board [Qc Js 5d Ah 4h]
Seat 1: folded before Flop (didn't bet)
Seat 2: donkey (button) showed [Ts 4s] and lost with a pair of Fours
Seat 3: (small blind) folded before Flop
Seat 4: shark (big blind) showed [As Ad] and won (3010) with three of a kind, Aces
Seat 5: folded before Flop (didn't bet)
Seat 6: folded before Flop (didn't bet)
Seat 7: folded before Flop (didn't bet)
Seat 8: folded before Flop (didn't bet)
Seat 9: hero folded before Flop (didn't bet)
Seat 10: folded before Flop (didn't bet)

And this one:

I was involved here, and once again... There must be something in the water.

PokerStars Game #_: Tournament #_, $50+$2 Hold'em No Limit - Level IV (50/100) - 2008/10/19 3:21:33 ET
Table '_ 1' 10-max Seat #4 is the button
Seat 1: (1640 in chips)
Seat 3: (1515 in chips)
Seat 4: (3465 in chips)
Seat 5: (1215 in chips)
Seat 7: villain (2000 in chips)
Seat 8: (1870 in chips)
Seat 9: hero (1975 in chips)
Seat 10: (1320 in chips)
[skip a bunch of lines of everybody putting in a 10 chip ante]
Seat 5: posts small blind 50
villain: posts big blind 100
*** HOLE CARDS ***
Dealt to hero [Kd Ks]
Seat 8: folds
hero: raises 200 to 300
Seat 10: folds
Seat 1: folds
Seat 3: folds
Seat 4: folds
Seat 5: folds
villain: raises 1690 to 1990 and is all-in
hero: calls 1665 and is all-in
Uncalled bet (25) returned to villain

He turns up 5To.

Really? I was making a bull-crap move from 2nd position? Having played almost no hands so far?

*** FLOP *** [4h Jh 6h]
*** TURN *** [4h Jh 6h] [2h]
*** RIVER *** [4h Jh 6h 2h] [4s]
*** SHOW DOWN ***
villain: shows [5c Ts] (a pair of Fours)
hero: shows [Kd Ks] (two pair, Kings and Fours)
hero collected 4060 from pot
*** SUMMARY ***
Total pot 4060 | Rake 0
Board [4h Jh 6h 2h 4s]
Seat 1: folded before Flop (didn't bet)
Seat 3: folded before Flop (didn't bet)
Seat 4: (button) folded before Flop (didn't bet)
Seat 5: (small blind) folded before Flop
Seat 7: villain (big blind) showed [5c Ts] and lost with a pair of Fours
Seat 8: folded before Flop (didn't bet)
Seat 9: hero showed [Kd Ks] and won (4060) with two pair, Kings and Fours
Seat 10: folded before Flop (didn't bet)

Friday, October 17, 2008

Nice call, eeyore

Full Tilt Poker Game #_: $110 + $9 Sit & Go (Turbo) (_ Table 1 - 80/160 - No Limit Hold'em - 10:26:14 ET - 2008/10/17
Seat 1: (1,230)
Seat 5: (3,920), is sitting out
Seat 6: (850)
Seat 7: villain (4,650)
Seat 8: hero (2,850)
villain posts the small blind of 80
hero posts the big blind of 160
The button is in seat #6
*** HOLE CARDS ***
Dealt to hero [3h 3d]
Seat 1 folds
Seat 5 folds
Seat 6 folds
villain calls 80
hero raises to 480
villain calls 320
*** FLOP *** [7c 4s 7h]
villain checks

He called a raise. The only hand I would do that with in this spot would be a couple of face cards or maybe a dry ace. If he has A7 then that would suck, but it's unlikely. This guy has been getting out of line all day long, so I think I can get paid in this spot.

hero bets 2,370, and is all in
villain calls 2,370
hero shows [3h 3d]
villain shows [9d 7d]

Fucking donkey. Keep calling my raises with shit.

*** TURN *** [7c 4s 7h] [2h]
*** RIVER *** [7c 4s 7h 2h] [8h]
hero shows two pair, Sevens and Threes
villain shows three of a kind, Sevens
villain wins the pot (5,700) with three of a kind, Sevens
hero stands up
*** SUMMARY ***
Total pot 5,700 | Rake 0
Board: [7c 4s 7h 2h 8h]
Seat 1: didn't bet (folded)
Seat 5: didn't bet (folded)
Seat 6: (button) didn't bet (folded)
Seat 7: villain (small blind) showed [9d 7d] and won (5,700) with three of a kind, Sevens
Seat 8: hero (big blind) showed [3h 3d] and lost with two pair, Sevens and Threes

Thursday, October 16, 2008

AP screws up statistics, film at 11

From this story about a deadly helicopter ambulance accident, comes this little tidbit:

It was the sixth fatal crash involving medical helicopters this year, according to federal data, including one just last month in Maryland that also killed four.
[...]
On Sept. 28, a medical helicopter carrying traffic accident victims crashed in a Maryland suburb, killing four of the five people on board. On June 8, a copter crashed on an isolated ranch in the Sam Houston National Forest in Texas, killing a patient and three crew members. Those and other crashes have raised questions on whether medical ambulance flights are overused.


Really?

Six incidents and you're ready to question the safety of medical ambulance flights? How many people die every year in four-wheeled ambulance accidents? I'd rather question whether or not perhaps helicopters are underutilized as ambulances if I were merely inclined to make judgments on accident statistics in isolation.

Stupid AP. No cookie for you. Instead, you get the Golden [Citation Needed] award.

ATSC vs DVB for North American amateurs

Fred Spinner, W0FMS, posted a comment to an earlier post that I think is deserving of a prominent reply. Here's his comment:

A okay quality DVB-S receiver can be had for far less cost than a PC electronics downconverter. All that likely would be necessary is a preamp at the antenna. I've seen PC card DVB receivers go for $10 and used DVB-S receivers go for $30. New ones, non high def, are less than $100 at the low end.

The disadvantage of ATSC is the complexity and the fact that you are transmitting on a 6 MHz channel. A DVB-S transmission can be done in good quality at about 2 MHZ. Also QPSK isn't going to be nearly as touchy as 8VSB as far as linearity is concerned. I've experimented with both-- I have an e-bay ATSC modulator/transmitter (formally used for demos at "Best Buy") and I find the fiddling that has to be done with ATSC (such as PSIP) data to be a big waste of effort.

The only disadvantage with DVB-S is multipath as QPSK/Satellite isn't really designed for that.. but if you are going to use gain antennas on both ends who cares? The MPEG-2 DVB-S or S2 standards are also far more lenient of audio and video rates. I suppose if you'd like to be cutting edge DVB-S2 and MPEG-4 H.264 would even be better than ATSC.... It's possible to do HD at low rates with H.264 and still only use 2-3 MHz of bandwidth.

I do hope if you are going to use ATSC for a repeater output that you strongly consider multiplexing multiple input receivers.. otherwise you are literally wasting the spectrum that the null packets consume.


Everything Fred says is true on its face. I still, however, believe that ATSC for amateur TV is not a completely wasted effort.

Although DVB-S receivers can be had for cheap, DVB-T would be the better mode for terrestrial reception (it is, after all, what European broadcasters themselves use). DVB-T receivers not only would be uncommon here in North America, they'd likely not be set up for the U.S. Amateur bands. DVB-S receivers also are going to require some fiddling to get them to work.

But some ATSC receivers are frequency agile enough to be able to work at least on the 73 cm ham band (I'm thinking mostly of computer controlled receivers, like the HD HomeRun or DTV receiver cards). I have some hopes that the HD HomeRun may work on the 900 MHz band as well. We'll have to see. But even if we have to use downconverters to tune alternate bands into the receive range of a traditional ATSC receiver, those downconverters could also be used for analog TV as well. And, as Alton Brown is fond of saying, I look down on unitaskers. :)

We hams have been extraordinarily lucky that for the past 30 years or so cable ready TVs were able to receive 70 cm ATV transmissions completely without modification. I wonder how many TV hams we'd have today if it weren't for the fact that anyone could take a consumer TV, attach a different kind of antenna to the input and tune in the local repeater. With the transition to digital, the chickens are coming home to roost and this happy coincidence is going to go away. Because most (but not all) ATSC receivers are not frequency agile enough to tune amateur bands, we won't be able to tell interested folks that all they have to do is tune their TV to a certain channel. But the opposite side of that coin is that in a few years' time after the transition is complete and the last generation of analog TVs is put out to pasture, there will be a boat load of old ATSC converter boxes that potentially could be modified (perhaps simply by supplying alternative firmware) into amateur TV decoders. There's also all of those PC controlled receivers that are frequency agile.

Fred's last comment about bandwidth is also true - and it is certainly the case that the intent is for the system to multiplex multiple inputs eventually. But you have to walk before you can run. Eventually, I'd like to see the system have 4 video channels: an outdoor camera, an analog TV input, a digital TV input, and a system information slide show.

Tuesday, October 14, 2008

Full Tilt Poker Matrix SnGs

Have you ever thought that you were better than the rest of the folks at the table, but that you couldn't prove it because of a cold deck or bad beat?

Full Tilt has introduced a new concept called a Matrix Sit-n-Go. The idea is that they take 9 players and sit them down to 4 simultaneous single table SnG tournaments. It's one thing to get lucky and win a tournament. It's quite another to pwn the same field of 9 over the course of 4 independent ones.

But is it worth it? Let's analyze the Matrix and see how far down the rabbit hole goes.

There are actually 5 prize pools in a Matrix tournament - one for each of the individual tournaments, plus an overall prize pool for the Matrix itself. The prize pools take the traditional 50%, 30%, 20% breakdown for 1st, 2nd and 3rd. If you win all four of the individual tournaments, you can "scoop" the Matrix pool. So let's make the math easy - There are 50 "points" for the Matrix, and winning any of the contests gets you 5, coming in 2nd gives you 3 and coming in 3rd gives you 2. "Scooping" the Matrix gives you 10. So the best you can theoretically do is 4 * 5 + 10 - 30 points. For a $22+$2 Matrix SnG, each point is worth $3.96, so that's $118.80. If you instead had entered 4 plain SnGs each worth $5.50 + $0.50 (which is the $22+$2 divided by four), you'd have won $99. That's a premium of $19.80, or 20%. The next best finish you can get is winning 3 of them and placing 2nd in the 4th. No scoop for you! Instead, you'd almost certainly win the Matrix prize, plus 3 1st place and 1 2nd place, or 4 * 5 + 3 - 23 points. That's $91.08, compared to the alternative of $89.10 - a premium of only 2%!

Still, I played a $22+$2 one for the novelty of it. I didn't do too badly. I won two of the four tournaments, placed 4th in the third (bad beat) and 9th in the last (made an ill advised move against pocket kings). I wound up 1st in the Matrix prize pool, so I earned 15 points, or $59.40. Had I played individually, I would have won $49.50 - a 20% premium.

Here's how it broke down:



Figuring out who benefitted is easy. Everybody who cashed at all cashed 20% less than they would have, except for the 3 of us who cashed in the Matrix pool. So if you don't make it into the upper echelons pretty predictably, you probably should avoid these. I may play one once in a while for the novelty of it, but playing 4 SnGs at the same time is a bit more busy than I would normally want to be.

More N6QQQ video on YouTube

Mike taped and uploaded some more of my ATV transmissions.

Saturday, October 11, 2008

More Analog ATV success

I decided to mount the 1.2 GHz loop yagi pointed towards K6BEN/R today. Of course, that also meant getting a run of really good (LMR-400) coax to go up the tower for it. Soldering the N connectors on is sort of weird. I have to sort of take it on blind faith that I did it right, I guess, because it appears to be working correctly.

Right now, the run of coax is way too long, but I am going to cut a hole in the outside wall of the garage above the sliding door and epoxy in a big piece of PVC to use as a pass-through (Scarlet will just love how that looks!) to make the coax runs as short as possible. I bought a long enough piece of the LMR coax so that hopefully I can get two runs up the tower out of it and use the other piece for the 420 MHz receive side. That should hopefully improve my reception side a little bit as well.

But at least now getting into the ATV repeater is no longer extraordinary.

Monday, October 6, 2008

Gizmo vs CalTrain

Gizmo seems bemused by my HO gauge CalTrain.

A quick tour of bay area TV via spectrum analyzer

Playing around with the new spectrum analyzer.

OJ

So OJ was found guilty on all counts stemming from his involvement with a wacky scheme to retrieve stuff that he says was his.

My my my.

Let's say that that stuff really was his. How did it come into the hands of this other guy? Could it be because OJ was trying to hide assets from the Goldmans?

Let's FURTHER presume that the whole thing was on the up-and-up. If you were in OJ's shoes, wouldn't your next step be to call either the cops to bust the other guy for possession of stolen property, or call a lawyer to sue?

But most importantly, if you were going to be forced to spend the rest of your life in a rather intense tabloid spotlight, wouldn't you try to be sure to be on your best behavior? Is a scheme involving other guys toting guns in any way compatible with that concept?

I'm pretty sure that OJ was guilty of something. It may not have been exactly what he was actually convicted for, but it's probably pretty close.


Analog ATV video

Michael Wright (K6MFW) recorded my first analog transmission through K6BEN and put it up on YouTube!