We've got a season pass to Conan, and I can't help but complain about the surround mix. There's way too much in the surround channels. It sounds like more of the show is happening behind you than in front.
It's particularly bad during the opening theme music. Andy's introductions are almost completely inaudible.
Now, I'm really, really, sure our system is set up right. And no other shows sound bad like this. We don't really watch anything else on TBS, so I'm not sure whether it's just Conan or everything on TBS. But it is messed the hell up.
But, of course, Conan's website doesn't have any contact information, and neither does TBS's. I could, I suppose, tweet to Conan about it, if I had ever bothered to sign up for twitter. So instead, since I have nobody better to complain to, I'll just whine to all of you. :)
Showing posts with label tv. Show all posts
Showing posts with label tv. Show all posts
Saturday, March 19, 2011
Saturday, January 22, 2011
HD, FTW
A few years ago (maybe it was in 2001. I don't remember), 2001: A Space Odyssey had a brief nationwide theatrical run. This was my first opportunity to see a movie that was made to be shown in a theater before I was born on a big screen, as it was intended. I had, of course, seen the film before, but always on Television, which until only recently meant NTSC video. Seeing it in the theater was a tremendous revelation. There was just an amazing amount of detail in the original film that I had never seen in all of the times I had seen the film on TV. The most striking example of this is in the scene when the lunar lander was being lowered into the moonbase. On either side of the elevator there are numerous windows, none of which were truly distinctly discernible on TV. There were actors walking around doing stuff and video screens displaying changing information while the lander was descending, all of which lent an extra air of reality to the scene. No doubt Stanley Kubrick went to a lot of extra trouble to add that in, knowing that people were going to be able to see it and that it would make the scene look just that much more realistic.
All that was nice and all, but I had my doubts that even HD would be able to present as much detail as that.
Turns out, I was wrong.
Just on a whim I decided to watch 2001 via Netflix Watch Now on the TiVo. Our Internet connection is good enough that we pretty routinely now get the highest quality streams available.
The stream they're showing now is every bit as nice as what I saw in the theater that day. All those details are clearly visible on our 50" TV from 8 feet away.
In hindsight, it should have been obvious to me. All you need to do is watch a little bit of an NFL game in SD and then HD to see the difference. It's not subtle. Not even a little.
All that was nice and all, but I had my doubts that even HD would be able to present as much detail as that.
Turns out, I was wrong.
Just on a whim I decided to watch 2001 via Netflix Watch Now on the TiVo. Our Internet connection is good enough that we pretty routinely now get the highest quality streams available.
The stream they're showing now is every bit as nice as what I saw in the theater that day. All those details are clearly visible on our 50" TV from 8 feet away.
In hindsight, it should have been obvious to me. All you need to do is watch a little bit of an NFL game in SD and then HD to see the difference. It's not subtle. Not even a little.
Sunday, September 19, 2010
NFL Red Zone
We've just recently switched to Comcast from DirecTV. Having done so, I've gotten my first taste of the NFL Red Zone channel. I'm not sure if it's an introductory thing (and will be turned off at some point), or if it's something that comes with the package I've signed up for. All I know is that on DirecTV, you had to pay for the NFL Sunday Ticket package ($300 a year) to get it.
It's the ultimate in short-attention-span football coverage. They put up whatever game happens to have a team in the best scoring position at that moment. No commercials, no bullshit.
It's a wonderful alternative to being stuck watching nothing but the Raiders or 49ers most Sundays around here.
Update It turns out it was a free preview for this weekend. Bummer.
It's the ultimate in short-attention-span football coverage. They put up whatever game happens to have a team in the best scoring position at that moment. No commercials, no bullshit.
It's a wonderful alternative to being stuck watching nothing but the Raiders or 49ers most Sundays around here.
Update It turns out it was a free preview for this weekend. Bummer.
Tuesday, September 7, 2010
pyTivoX... FTW!!!
So we have a TiVo Premiere in the living room connected up to our TV. Since we have only the one DVR now, our TV in the bedroom would ostensibly be useless, so I moved the mac mini from the living room in there. We can use iTivo to watch shows on it.
But that means that we now have no way of watching dvds in the living room, since the mini was the only DVD drive out there.
Turns out, there's a good solution.
PyTiVoX is a program that acts as a server that does the opposite of TiVoToGo - a sort of TiVoComeFrom, as it were. It will take a directory full of video files and put up a server that looks just like a TiVo. If you ask a real TiVo to transfer a file, it will convert it to MPEG2/AC3 on the fly and transfer it over. Alternatively, if you have a TiVoHD or Premiere, you can stream the stuff instead of transferring it (it shows up in the Showcases menu rather than in Now Playing).
So you can rip a DVD with Handbrake, toss the resulting video file into a pyTivoX share directory and then watch it on the TiVo. It takes a little extra time for Handbrake to do its work, but even with that, it's a good solution.
The only pity is that it doesn't work for DRMed content you can't break, such as iTunes video purchases or amazon movies or the like. But as long as they keep either making DVDs or making the stuff available on Netflix watch now, I'll be happy.
But that means that we now have no way of watching dvds in the living room, since the mini was the only DVD drive out there.
Turns out, there's a good solution.
PyTiVoX is a program that acts as a server that does the opposite of TiVoToGo - a sort of TiVoComeFrom, as it were. It will take a directory full of video files and put up a server that looks just like a TiVo. If you ask a real TiVo to transfer a file, it will convert it to MPEG2/AC3 on the fly and transfer it over. Alternatively, if you have a TiVoHD or Premiere, you can stream the stuff instead of transferring it (it shows up in the Showcases menu rather than in Now Playing).
So you can rip a DVD with Handbrake, toss the resulting video file into a pyTivoX share directory and then watch it on the TiVo. It takes a little extra time for Handbrake to do its work, but even with that, it's a good solution.
The only pity is that it doesn't work for DRMed content you can't break, such as iTunes video purchases or amazon movies or the like. But as long as they keep either making DVDs or making the stuff available on Netflix watch now, I'll be happy.
Thursday, September 2, 2010
Lies, damn lies and marketing
I cancelled our DirecTV service this evening after being a customer for more than 15 years.
As is always the case, my cancellation was handled by the "save" department. This is the bunch of phone reps whose job it is to do whatever it takes to prevent you from canceling your service. Every subscription service oriented company has them. Some are more pernicious than others. It should be no surprise at all that companies are working harder than ever to make their web sites handle every possible customer need conceivable.
Except that one.
No, AOL never had a "cancel my service" button. Neither did XM.
Netflix, to their credit, does. And they don't hide it. It's the third link down from the top of the page on the "Your account" screen. They ask you why you're leaving, but otherwise they don't make a fuss. Even if I didn't have them on my resume, I'd admire that attitude.
The DirecTV guy I had on the phone tried to drag Comcast through the mud in a couple of ways - comparing the customer satisfaction ratings of the two companies. He even said, and I am quoting him directly here, "Did you know Comcast has no HD?"
After a moment of stunned silence, I told him I was looking at an HD picture as we speak. He then said, "no, that's 720p. Comcast has no true HD."
Oh. My. God.
Let's look at the situation here.
Comcast's goal is to deliver as much video as they can with as little bandwidth as possible. Ironically, that's also DirecTV's goal - a goal that DirecTV has achieved by switching over to MPEG4 as their main HD codec, which raises the cost of their receivers. But never mind that for now.
720p and 1080i actually take about the same amount of bandwidth. So if you were of the mistaken opinion that 720p was somehow not "true" HD (which it is, by the way.480i is SD, 480p is ED and anything above that is HD), what benefit would it be for Comcast to somehow transcode all 1080i programming to 720p?
No. 720p and 1080i are equal alternatives. 720p is good for high action programming, like sports, and 1080i is better for mostly static programming. But there's never any need or justification for anyone to spend the money to convert one to the other.
Far more likely that that DirecTV rep was lying. Go figure.
The one disappointment I am left with in this whole thing is that we somehow wound up with one of our DVRs being leased. We had an HR21 die on us and it was replaced, and we didn't own the replacement. Go figure that out. So they're going to ship is an empty box to mail it back. Whatever. Even without that, we should wind up getting about half of what we paid for the TiVo out of our old DirecTV gear on eBay.
And with TiVo, we get TiVo to go, so we can liberate our programming from the confines of what The Man says we can do with it. And that, more than anything, is what pissed me off about DirecTV. They went so far out of their way to lock down their programming that they made their service unusable, and/or used that draconian lock to squeeze extra nickels out of us.
No thanks.
As is always the case, my cancellation was handled by the "save" department. This is the bunch of phone reps whose job it is to do whatever it takes to prevent you from canceling your service. Every subscription service oriented company has them. Some are more pernicious than others. It should be no surprise at all that companies are working harder than ever to make their web sites handle every possible customer need conceivable.
Except that one.
No, AOL never had a "cancel my service" button. Neither did XM.
Netflix, to their credit, does. And they don't hide it. It's the third link down from the top of the page on the "Your account" screen. They ask you why you're leaving, but otherwise they don't make a fuss. Even if I didn't have them on my resume, I'd admire that attitude.
The DirecTV guy I had on the phone tried to drag Comcast through the mud in a couple of ways - comparing the customer satisfaction ratings of the two companies. He even said, and I am quoting him directly here, "Did you know Comcast has no HD?"
After a moment of stunned silence, I told him I was looking at an HD picture as we speak. He then said, "no, that's 720p. Comcast has no true HD."
Oh. My. God.
Let's look at the situation here.
Comcast's goal is to deliver as much video as they can with as little bandwidth as possible. Ironically, that's also DirecTV's goal - a goal that DirecTV has achieved by switching over to MPEG4 as their main HD codec, which raises the cost of their receivers. But never mind that for now.
720p and 1080i actually take about the same amount of bandwidth. So if you were of the mistaken opinion that 720p was somehow not "true" HD (which it is, by the way.480i is SD, 480p is ED and anything above that is HD), what benefit would it be for Comcast to somehow transcode all 1080i programming to 720p?
No. 720p and 1080i are equal alternatives. 720p is good for high action programming, like sports, and 1080i is better for mostly static programming. But there's never any need or justification for anyone to spend the money to convert one to the other.
Far more likely that that DirecTV rep was lying. Go figure.
The one disappointment I am left with in this whole thing is that we somehow wound up with one of our DVRs being leased. We had an HR21 die on us and it was replaced, and we didn't own the replacement. Go figure that out. So they're going to ship is an empty box to mail it back. Whatever. Even without that, we should wind up getting about half of what we paid for the TiVo out of our old DirecTV gear on eBay.
And with TiVo, we get TiVo to go, so we can liberate our programming from the confines of what The Man says we can do with it. And that, more than anything, is what pissed me off about DirecTV. They went so far out of their way to lock down their programming that they made their service unusable, and/or used that draconian lock to squeeze extra nickels out of us.
No thanks.
The new Apple TV
Oh, Steve, you could have really revolutionized the living room if you'd just have tried a little bit harder.
Where is the iTunes app store for the Apple TV?
Yes, fine, you added Netflix streaming. But what about Pandora? What about XM/Sirius? What about Hulu? What about all of the other streaming media sources on the Internet that want to get onto the TV?
Maybe that's what AirPlay will wind up being. If AirPlay is an API feature that will be available universally to all app store developers, then the AppleTV will wind up being nothing more than a remote display for iOS. That would be ok, I suppose, but if AirPlay is limited to the iPod app, then, again, it's the same opportunity lost.
I see from the AirPlay page that they're going to make AirPlay available to third parties. Please, TiVo, please add AirPlay receiving. Please.
Where is the iTunes app store for the Apple TV?
Yes, fine, you added Netflix streaming. But what about Pandora? What about XM/Sirius? What about Hulu? What about all of the other streaming media sources on the Internet that want to get onto the TV?
Maybe that's what AirPlay will wind up being. If AirPlay is an API feature that will be available universally to all app store developers, then the AppleTV will wind up being nothing more than a remote display for iOS. That would be ok, I suppose, but if AirPlay is limited to the iPod app, then, again, it's the same opportunity lost.
I see from the AirPlay page that they're going to make AirPlay available to third parties. Please, TiVo, please add AirPlay receiving. Please.
TiVo + Comcast begins
DirecTV is fired.
The TiVo Premiere arrived Tuesday night and Comcast came yesterday.
We'd been using DirecTV for 15+ years, so when we moved into our house we never hooked up the cable. A month or so later comcast physically disconnected our cable and left it dangling in the wind. So when we called them up for new service, I assumed they might need to cut off the last few inches of that cable, put a new connector on it and plug it in.
I was a little surprised that the tech instead actually replaced the entire drop. But he did a solid, professional job, and he arrived on time in the middle of the two hour window. All in all, I now have as high an opinion of Comcast's field service techs as I do of PacBell/SBC/AT&T.
Installing the CableCard took way too long and was way too much trouble, but this may simply be a self fulfilling prophecy. We stuck the card in and he made a phone call to give two series of numbers to the mothership. That done, the TiVo went into a mode where it was trying to acquire the channel list. That went on for too long, so we started doing stuff. What finally worked was repeating guided setup. Either doing that fixed... something... or it simply took so long to do that in the meantime the card got whatever it needed from the mothership and turned on. The problem is that both I and the tech had heard so many horror stories about TiVos and CableCards that we expected the worst from the start.
The biggest problem we face right now is that the TiVo has four copies of our local stations. Not kidding. We have our antenna plugged into the TiVo along with Comcast so that we can get some of the out-of-market stations that come in for us. So, for example, for KTVU, we get it on 2-1 (antenna), plus a copy of the signal on the analog portion of the cable, an SD digital channel and an HD digital cable channel. This is ok, except that I caught the TiVo taping a suggestion from the analog cable channel! Bad TiVo! If you're going to tape a suggestion, at LEAST tape an HD version if it's available (or at least include some sort of option to let me pick which to prefer)! So now I need to go through the channel list in the TiVo and remove all of the SD versions of channels for which we get an HD version.
The only other complaint I have about the TiVo is that it refuses to use the 1TB eSATA hard disk I plugged into it. Instead, they insist that I buy a particular one. Grumble. I can only assume that they've run into support issues and have taken this extra step to cut down on the number of support calls they get related to low quality eSATA drives. Fortunately, the eSATA drive they want you to use doesn't cost more than the same drive does otherwise - that is, they're not charging a premium for it being TiVo compatible. I'm probably not going to go out and get one, however, since the whole idea behind having a TiVo is being able to offload the shows from it onto the computers using iTiVo.
The TiVo Premiere arrived Tuesday night and Comcast came yesterday.
We'd been using DirecTV for 15+ years, so when we moved into our house we never hooked up the cable. A month or so later comcast physically disconnected our cable and left it dangling in the wind. So when we called them up for new service, I assumed they might need to cut off the last few inches of that cable, put a new connector on it and plug it in.
I was a little surprised that the tech instead actually replaced the entire drop. But he did a solid, professional job, and he arrived on time in the middle of the two hour window. All in all, I now have as high an opinion of Comcast's field service techs as I do of PacBell/SBC/AT&T.
Installing the CableCard took way too long and was way too much trouble, but this may simply be a self fulfilling prophecy. We stuck the card in and he made a phone call to give two series of numbers to the mothership. That done, the TiVo went into a mode where it was trying to acquire the channel list. That went on for too long, so we started doing stuff. What finally worked was repeating guided setup. Either doing that fixed... something... or it simply took so long to do that in the meantime the card got whatever it needed from the mothership and turned on. The problem is that both I and the tech had heard so many horror stories about TiVos and CableCards that we expected the worst from the start.
The biggest problem we face right now is that the TiVo has four copies of our local stations. Not kidding. We have our antenna plugged into the TiVo along with Comcast so that we can get some of the out-of-market stations that come in for us. So, for example, for KTVU, we get it on 2-1 (antenna), plus a copy of the signal on the analog portion of the cable, an SD digital channel and an HD digital cable channel. This is ok, except that I caught the TiVo taping a suggestion from the analog cable channel! Bad TiVo! If you're going to tape a suggestion, at LEAST tape an HD version if it's available (or at least include some sort of option to let me pick which to prefer)! So now I need to go through the channel list in the TiVo and remove all of the SD versions of channels for which we get an HD version.
The only other complaint I have about the TiVo is that it refuses to use the 1TB eSATA hard disk I plugged into it. Instead, they insist that I buy a particular one. Grumble. I can only assume that they've run into support issues and have taken this extra step to cut down on the number of support calls they get related to low quality eSATA drives. Fortunately, the eSATA drive they want you to use doesn't cost more than the same drive does otherwise - that is, they're not charging a premium for it being TiVo compatible. I'm probably not going to go out and get one, however, since the whole idea behind having a TiVo is being able to offload the shows from it onto the computers using iTiVo.
Wednesday, June 9, 2010
Mythbusters - myth... exaggerated?
Mythbusters just aired an episode that included the myth that a sneeze goes 100 mi/hr and can travel 30 feet. The experimental results: just under 40 mi/hr and a maximum of 17 feet. They called it "busted."
So yes, at a literal level, they got somewhere around 50% of what the myth says, and 50% ain't 100%, so yes. But I think the literal numbers as stated in the myth are much less important than the message of the myth, which is that a sneeze goes faster and further than you probably expect. 17 feet is across a whole room, after all. A waiter sneezing in the corner of a restaurant could conceivably hit every diner in the place.
And this isn't the first time a myth had such a result. So I think I'd call this myth exaggerated rather than busted. I think if a sneeze went 10 mi/hr and only went 5 feet you'd be able to say it's definitely busted. But in this case, I think busted is just too harsh.
So yes, at a literal level, they got somewhere around 50% of what the myth says, and 50% ain't 100%, so yes. But I think the literal numbers as stated in the myth are much less important than the message of the myth, which is that a sneeze goes faster and further than you probably expect. 17 feet is across a whole room, after all. A waiter sneezing in the corner of a restaurant could conceivably hit every diner in the place.
And this isn't the first time a myth had such a result. So I think I'd call this myth exaggerated rather than busted. I think if a sneeze went 10 mi/hr and only went 5 feet you'd be able to say it's definitely busted. But in this case, I think busted is just too harsh.
Friday, May 21, 2010
This is how you lose a loyal customer
For about 4 months now, we've been enjoying the multi-room viewing beta with our DirecTV DVRs. This morning, it was summarily turned off. I went to the DirecTV website and discovered that they now want to charge $3/mo for it.
Offense number one: nickel-and-diming your customers.
Fine. I clicked on the button to activate it. The response? "Sorry, your account is ineligible. Please call yadda yadda." So I call, and get someone who says we need to change our plan or something. So we have free Showtime and Starz for 3 months..... but we must remember to call them back and turn it off or they'll start charging for it. Grumble.
Offense number two: sneaky customer lock-in "special offers."
After 20 minutes on hold, I got to the right person... who said that this feature was no longer available on the model of DVR we have. Instead, I would need to upgrade to the latest one.
Offense number three: Oh, there's just too many to count.
I've had it.
I've been a loyal DirecTV customer for 15 years now. First, they gave us substandard TiVos and didn't keep up with the new features. Then they replaced them with their own DVRs that we effectively had to beta test for them. Then, when they finally catch up with features that TiVo has had for years now, they shit on us and call it pudding.
We're going to save up for TiVos, and we'll be switching to Comcast. The really sad part is that I don't expect that they'll shit on us any less. But at least with real TiVos they'll have one less avenue with which they can do it.
Offense number one: nickel-and-diming your customers.
Fine. I clicked on the button to activate it. The response? "Sorry, your account is ineligible. Please call yadda yadda." So I call, and get someone who says we need to change our plan or something. So we have free Showtime and Starz for 3 months..... but we must remember to call them back and turn it off or they'll start charging for it. Grumble.
Offense number two: sneaky customer lock-in "special offers."
After 20 minutes on hold, I got to the right person... who said that this feature was no longer available on the model of DVR we have. Instead, I would need to upgrade to the latest one.
Offense number three: Oh, there's just too many to count.
I've had it.
I've been a loyal DirecTV customer for 15 years now. First, they gave us substandard TiVos and didn't keep up with the new features. Then they replaced them with their own DVRs that we effectively had to beta test for them. Then, when they finally catch up with features that TiVo has had for years now, they shit on us and call it pudding.
We're going to save up for TiVos, and we'll be switching to Comcast. The really sad part is that I don't expect that they'll shit on us any less. But at least with real TiVos they'll have one less avenue with which they can do it.
Sunday, January 3, 2010
NFL - final week 2009
The ability to receive KCBA has given the biggest benefit of the season today.
Because the Raiders are playing at home today, KTVU cannot air the Eagles / Cowboys game, which is one of the really pivotal games being played today. The winner largely determines the seating order for the NFC playoffs - never mind the fact that Eagles / Cowboys is a storied rivalry.
On behalf of everyone in the bay area who cannot get KCBA, I'd like to send a message to Al Davis:
Please, please, please for the love of God, move your pile of shit team back to LA. Or Reno. "Reno Raiders" - that has a great ring to it.
If you don't like that, try Montana or Wyoming. Just anywhere but here.
Because the Raiders are playing at home today, KTVU cannot air the Eagles / Cowboys game, which is one of the really pivotal games being played today. The winner largely determines the seating order for the NFC playoffs - never mind the fact that Eagles / Cowboys is a storied rivalry.
On behalf of everyone in the bay area who cannot get KCBA, I'd like to send a message to Al Davis:
Please, please, please for the love of God, move your pile of shit team back to LA. Or Reno. "Reno Raiders" - that has a great ring to it.
If you don't like that, try Montana or Wyoming. Just anywhere but here.
Sunday, December 20, 2009
Really, NFL?
We're close to the playoffs. And of all of the games this weekend, there is one that is the most important.
The Chargers are hosting the Bengals at home. The Chargers are one game ahead of the Bengals in the drive for the 2nd AFC playoff seed - which means a first round bye.
In the latter part of the season, the NFL and the networks have the opportunity to "flex" the schedule - to make a more important game the Sunday night game, relegating what was scheduled in the pre-season back to Sunday afternoon (or morning).
So it didn't occur to anybody that this crucial game is worthy of being played on Sunday night? They think Vikings - Panthers is more important somehow? Really?! The Vikings are almost assured of either the #1 or #2 seed in the NFC and the Panthers are all but mathematically eliminated. Who gives a shit?
The only other game even close to how important that game is is the Eagles and 49ers. The 49ers need a win to even have a chance at a wildcard spot, while the Eagles are almost assured of the number 3 seed in the NFC. Of course, since the 49ers are the home team here, it'll be on Fox for sure.
The wrinkle is that the weather has screwed up the game schedules on the East coast. So potentially, the CBS morning game might have been the Chargers', but now that game will be played at the same time as the Raiders @ Broncos. Another "who cares?" game. But it's moot - Fox got the doubleheader today anyhow. Their rejiggered schedule today will give us the 49ers game in the afternoon, and of all of the remaining morning games to show us, they picked... Cardinals / Lions?! Does anybody honestly think the Lions have a shot at their third win this week?
Perhaps the single most important football game of the entire season. None for you!
The Chargers are hosting the Bengals at home. The Chargers are one game ahead of the Bengals in the drive for the 2nd AFC playoff seed - which means a first round bye.
In the latter part of the season, the NFL and the networks have the opportunity to "flex" the schedule - to make a more important game the Sunday night game, relegating what was scheduled in the pre-season back to Sunday afternoon (or morning).
So it didn't occur to anybody that this crucial game is worthy of being played on Sunday night? They think Vikings - Panthers is more important somehow? Really?! The Vikings are almost assured of either the #1 or #2 seed in the NFC and the Panthers are all but mathematically eliminated. Who gives a shit?
The only other game even close to how important that game is is the Eagles and 49ers. The 49ers need a win to even have a chance at a wildcard spot, while the Eagles are almost assured of the number 3 seed in the NFC. Of course, since the 49ers are the home team here, it'll be on Fox for sure.
The wrinkle is that the weather has screwed up the game schedules on the East coast. So potentially, the CBS morning game might have been the Chargers', but now that game will be played at the same time as the Raiders @ Broncos. Another "who cares?" game. But it's moot - Fox got the doubleheader today anyhow. Their rejiggered schedule today will give us the 49ers game in the afternoon, and of all of the remaining morning games to show us, they picked... Cardinals / Lions?! Does anybody honestly think the Lions have a shot at their third win this week?
Perhaps the single most important football game of the entire season. None for you!
Wednesday, October 28, 2009
DVB-S on the spectrum analyzer
Here's what DVB-S looks like on a spectrum analyzer:
This is with the modulator configured for a 4500 kilobaud signal, which results in a 6 MHz wide channel. With a FEC rate of 3/4, that's about 6 MB/sec or so of available MPEG bandwidth.
Compared to 8VSB, the envelope isn't quite so square - it rounds off a bit on either end. And, of course, there is no pilot at the bottom end like with 8VSB.
This is another SA view - this time it's calculating the channel average power and the adjacent channel power. Taking into account the 20 dB attenuator on the input of the SA, it's seeing a channel average power of about 4 watts, and the adjacent channels are 30 dB down from there.
This is with the modulator configured for a 4500 kilobaud signal, which results in a 6 MHz wide channel. With a FEC rate of 3/4, that's about 6 MB/sec or so of available MPEG bandwidth.
Compared to 8VSB, the envelope isn't quite so square - it rounds off a bit on either end. And, of course, there is no pilot at the bottom end like with 8VSB.
This is another SA view - this time it's calculating the channel average power and the adjacent channel power. Taking into account the 20 dB attenuator on the input of the SA, it's seeing a channel average power of about 4 watts, and the adjacent channels are 30 dB down from there.
N6QQQ/R bench test results
The receiver and my uplink DVB-S modulator have arrived from Germany. With the DEMI 2330PATV, I'm able to get about 4 watts of DVB-S power output. When I started bench testing the repeater, however, it turned out that even with the amp's bias turned off, the DVB-S exciter alone was enough to be received by the receiver. Not too much of a surprise, given that the exciter and receiver were about 3 feet apart in the garage.
I made a YouTube video showing a complete round-trip - from my analog camera, through the MPEG encoder, modulated with DVB-S, amplified to 4 watts and transmitted with my 23 cm 14 dBd loop Yagi. Then received on the DVB-S receiver, modulated as 8VSB on 33 cm, amplified to about 15 watts, then attenuated by 20 dB and run through a rubber duck antenna. Then received on the loop Yagi on the roof, downconverted from there to TV channel 3, and then received on my portable ATSC TV.
Whew!
The next step will be to start separating the up/downlink station and the repeater further and further apart. Hopefully, the last test will be with the repeater at its new home on the hill!
The next big demo will be at the K6BEN ATV luncheon on November 23rd. I'll schlep all of the gear for both the repeater and my uplink station over to Harry's Hofbrau and we'll try a full round-trip across the parking lot.
I made a YouTube video showing a complete round-trip - from my analog camera, through the MPEG encoder, modulated with DVB-S, amplified to 4 watts and transmitted with my 23 cm 14 dBd loop Yagi. Then received on the DVB-S receiver, modulated as 8VSB on 33 cm, amplified to about 15 watts, then attenuated by 20 dB and run through a rubber duck antenna. Then received on the loop Yagi on the roof, downconverted from there to TV channel 3, and then received on my portable ATSC TV.
Whew!
The next step will be to start separating the up/downlink station and the repeater further and further apart. Hopefully, the last test will be with the repeater at its new home on the hill!
The next big demo will be at the K6BEN ATV luncheon on November 23rd. I'll schlep all of the gear for both the repeater and my uplink station over to Harry's Hofbrau and we'll try a full round-trip across the parking lot.
Monday, October 26, 2009
PLL design
The North Country Radio downconverter kit arrived today. It's a bit daunting, but they did supply some suggestions on how to tap off the RF sample for the PLL and put in the VCO control voltage. That was nice of them.
It's hard to find PLL components anywhere - certainly there aren't any one stop shops anymore. Makes me wonder how companies prototype stuff like this in this day and age.
Jameco still sells the MC145151 in DIP packaging, which is convenient.
The North Country Radio downconverter schematic says that the VCO control voltage is 2 to 8 volts. That exceeds the 5 volts that run the MC145151 PLL, which means that the PLL loop filter will need to be an active one. Given that the reference frequency in this case is 15,625 Hz, the op amp for the active loop filter isn't going to have a lot asked of it - an LM741 would do just fine.
That just leaves a divide by 64 prescaler. That, it turned out, was hard to find, and impossible in DIP packaging. I wound up buying a µPB1507GV from Mouser, but I will need to solder it down to an SSOP-8 to DIP adapter board for prototyping.
The nice thing about working on PLLs is that only on the input side of the prescaler are you dealing with real RF - the entire rest of the circuit is dealing with low enough frequencies that it can all be breadboarded.
It's hard to find PLL components anywhere - certainly there aren't any one stop shops anymore. Makes me wonder how companies prototype stuff like this in this day and age.
Jameco still sells the MC145151 in DIP packaging, which is convenient.
The North Country Radio downconverter schematic says that the VCO control voltage is 2 to 8 volts. That exceeds the 5 volts that run the MC145151 PLL, which means that the PLL loop filter will need to be an active one. Given that the reference frequency in this case is 15,625 Hz, the op amp for the active loop filter isn't going to have a lot asked of it - an LM741 would do just fine.
That just leaves a divide by 64 prescaler. That, it turned out, was hard to find, and impossible in DIP packaging. I wound up buying a µPB1507GV from Mouser, but I will need to solder it down to an SSOP-8 to DIP adapter board for prototyping.
The nice thing about working on PLLs is that only on the input side of the prescaler are you dealing with real RF - the entire rest of the circuit is dealing with low enough frequencies that it can all be breadboarded.
Sunday, October 18, 2009
More PLL design
So the design at the moment for the downconverter looks like it'll use the MC145151 PLL and the SA620 LNA/Mixer/VCO. At first, I figured I'd use the MC12080 divide-by-80 prescaler. With a 12.8 MHz crystal and a divide by 1024 reference divisor, that's a channelization of 1 MHz. And that's fine for an ATV downconverter.
But what if we altered the design a bit to take advantage of the fractional capabilities of the a dual modulus PLL chip, like the MC145152?
If we used that same 12.8 MHz crystal and divide by 512, we'd have a 25 kHz reference frequency. With a divide-by-64/65 prescaler (like the MC12054A), we'd be able to achieve the same result, but with a 25 kHz channel step.
A PLL that can drive a dual modulus prescaler has two counters. One of them is the actual output into the phase comparator, the other causes a digital output to change state during each count cycle. That signal changes the prescaler from a divide by P+1 to a divide by P.
Let's say that we set the main counter value to N and the prescaler change counter to A and the lower of the two prescaler values to P. What we'd then wind up with is dividing the VCO output by P*N+A. If the reference frequency is R, then the output frequency will be R*(PN+A). So for 848 MHz, if P is 64, and R is 25 kHz, N would be set to 530 and A to 0. Set A to 1 and the output would instead be 848.025 MHz. For 849 MHz (which puts 909-915 down to TV channel 3), you set N to 530 and A to 40.
In general, for a desired frequency F, you set the N to the integral quotient of (F/R) divided by P. You then set A to (F/R) mod P. Stated another way, you're building a fraction of N + A/P, which winds up being equal to F/(P*R).
Of course, this does mean that the design will need more DIP switches. The MC145152 has 6 bits for the A value and 10 bits for the N value. That's two banks of 8 switches. You could fix the top 4 bits of N to 1000 - limiting N from 512 to 575. The resulting frequency range would be 819.2 MHz to 921.6 MHz - more than enough for our purposes. That's a total of 12 switches - two banks of 6.
So a 12.8 MHz crystal, an MC145152 PLL, and an MC12054A prescaler and an SA620 LNA/VCO/Mixer.
Now the big problem is either finding inventory on these parts somewhere or finding equivalents.
But what if we altered the design a bit to take advantage of the fractional capabilities of the a dual modulus PLL chip, like the MC145152?
If we used that same 12.8 MHz crystal and divide by 512, we'd have a 25 kHz reference frequency. With a divide-by-64/65 prescaler (like the MC12054A), we'd be able to achieve the same result, but with a 25 kHz channel step.
A PLL that can drive a dual modulus prescaler has two counters. One of them is the actual output into the phase comparator, the other causes a digital output to change state during each count cycle. That signal changes the prescaler from a divide by P+1 to a divide by P.
Let's say that we set the main counter value to N and the prescaler change counter to A and the lower of the two prescaler values to P. What we'd then wind up with is dividing the VCO output by P*N+A. If the reference frequency is R, then the output frequency will be R*(PN+A). So for 848 MHz, if P is 64, and R is 25 kHz, N would be set to 530 and A to 0. Set A to 1 and the output would instead be 848.025 MHz. For 849 MHz (which puts 909-915 down to TV channel 3), you set N to 530 and A to 40.
In general, for a desired frequency F, you set the N to the integral quotient of (F/R) divided by P. You then set A to (F/R) mod P. Stated another way, you're building a fraction of N + A/P, which winds up being equal to F/(P*R).
Of course, this does mean that the design will need more DIP switches. The MC145152 has 6 bits for the A value and 10 bits for the N value. That's two banks of 8 switches. You could fix the top 4 bits of N to 1000 - limiting N from 512 to 575. The resulting frequency range would be 819.2 MHz to 921.6 MHz - more than enough for our purposes. That's a total of 12 switches - two banks of 6.
So a 12.8 MHz crystal, an MC145152 PLL, and an MC12054A prescaler and an SA620 LNA/VCO/Mixer.
Now the big problem is either finding inventory on these parts somewhere or finding equivalents.
Make your own NFL doubleheader!
I'm watching the Giants and Saints game right now. It's on KCBA. Yay!
KTVU's scheduled to air the Cardinals-Seahawks game at 1. Last I heard, the Raiders hadn't sold out, so that game may not air. That would be our punishment, I guess, for not buying tickets to see JaMarcus throw picks and incompletes. Frank Caliendo said it best today - he called the Raiders "Clippers bad." Word.
Anyway, CBS's game today is Ravens-Vikings. So I am flipping back and forth between two games featuring teams off to a 5-0 start. Can't complain much about that! If KTVU indeed airs the Seahawks game this afternoon, well, I'll have gotten to see 3 games instead of 2. And thus, the antenna gambit pays off!
KTVU's scheduled to air the Cardinals-Seahawks game at 1. Last I heard, the Raiders hadn't sold out, so that game may not air. That would be our punishment, I guess, for not buying tickets to see JaMarcus throw picks and incompletes. Frank Caliendo said it best today - he called the Raiders "Clippers bad." Word.
Anyway, CBS's game today is Ravens-Vikings. So I am flipping back and forth between two games featuring teams off to a 5-0 start. Can't complain much about that! If KTVU indeed airs the Seahawks game this afternoon, well, I'll have gotten to see 3 games instead of 2. And thus, the antenna gambit pays off!
Saturday, October 17, 2009
K6BEN retransmitted digitally
Today I retransmitted the output of the K6BEN repeater digitally over ATSC.
As soon as N6QQQ/R goes live, I'll start doing this on Wednesday evenings just to sort of bootstrap the use of the new repeater - that way folks will have more to look at on it than just my garage.
As soon as N6QQQ/R goes live, I'll start doing this on Wednesday evenings just to sort of bootstrap the use of the new repeater - that way folks will have more to look at on it than just my garage.
Friday, October 16, 2009
Designing a downconverter
I've done some looking into it, and it appears that the three parts that would be the most useful would be the SA620 LNA, VCO and mixer, an MC145151-2 DIP switch controlled PLL, and an MC12080 UHF prescaler. From what I can tell, those three parts should be able to work together to downconvert from just about any frequency in the 33 cm band down to VHF channel 3 or 4.
Yeah, I know. In the last post, I made an argument for putting it in UHF instead. But the coax losses are much, much lower at VHF, so if it's reasonable or easy to make it happen, well, why not?
The big problem is, so far as I can tell, the SA620 and MC12080 are only available as surface mount devices. It'd be nice if they were available in DIP packaging. But, alas, no. SparkFun electronics, however, sells SOIC-8 and SSOP-20 to DIP adapter boards.
The concept is that the RF comes in and the LNA built-in to the 620 amplifies it a little and feeds it into the mixer. Meanwhile, the VCO generates the IF of about 850 MHz or thereabouts. A little of the VCO's output is fed through the prescaler, and then out to the PLL. The PLL then generates corrections for the VCO's voltage.
Those 3 chips total are less than $15, from what I can tell, from a combination of DigiKey and Jameco.
And that's all there is to it: 3 chips, a 5 volt regulator, 2 sets of DIP switches and some discrete components to tie it all together. For extra credit, it would be fairly simple to add a bias-T to the output to supply power to the thing to mast-mount it. And if it's going to be mast-mounted, then DIP switches are a completely reasonable way to set the LO frequency, since it'll be something you only set once.
In fact, if you're using a computer peripheral tuner, like the HDHomerun, you'll likely just set it for an LO frequency of 848 MHz - that would put 902 MHz at 54 MHz. You'd then just tell your tuner exactly what frequency it should use. The only reason for making the PLL as adjustable as it is is because TV sets aren't agile enough to hunt around other than on normal TV channels. The HDHomeRun, however, can easily be told to look for 8VSB on a channel center of 64 MHz - which is where the 909-915 MHz ATV channel would be found.
Yeah, I know. In the last post, I made an argument for putting it in UHF instead. But the coax losses are much, much lower at VHF, so if it's reasonable or easy to make it happen, well, why not?
The big problem is, so far as I can tell, the SA620 and MC12080 are only available as surface mount devices. It'd be nice if they were available in DIP packaging. But, alas, no. SparkFun electronics, however, sells SOIC-8 and SSOP-20 to DIP adapter boards.
The concept is that the RF comes in and the LNA built-in to the 620 amplifies it a little and feeds it into the mixer. Meanwhile, the VCO generates the IF of about 850 MHz or thereabouts. A little of the VCO's output is fed through the prescaler, and then out to the PLL. The PLL then generates corrections for the VCO's voltage.
Those 3 chips total are less than $15, from what I can tell, from a combination of DigiKey and Jameco.
And that's all there is to it: 3 chips, a 5 volt regulator, 2 sets of DIP switches and some discrete components to tie it all together. For extra credit, it would be fairly simple to add a bias-T to the output to supply power to the thing to mast-mount it. And if it's going to be mast-mounted, then DIP switches are a completely reasonable way to set the LO frequency, since it'll be something you only set once.
In fact, if you're using a computer peripheral tuner, like the HDHomerun, you'll likely just set it for an LO frequency of 848 MHz - that would put 902 MHz at 54 MHz. You'd then just tell your tuner exactly what frequency it should use. The only reason for making the PLL as adjustable as it is is because TV sets aren't agile enough to hunt around other than on normal TV channels. The HDHomeRun, however, can easily be told to look for 8VSB on a channel center of 64 MHz - which is where the 909-915 MHz ATV channel would be found.
Thursday, October 15, 2009
Final repeater pieces ordered
All the pieces are coming together.
The repeater will consist of
From SR Systems:
1 DVB-S 23cm receiver board
1 ATSC 33cm minimod
From Downeast Microwave:
1 3370PAHS amplifier
From Ham Radio Outlet:
1 Diamond X6000A 2M/70cm/23cm vertical antenna
1 Comet KP-20 33cm vertical antenna
I'm going to also set up an uplink station for myself. I want to use it at least at first to retransmit the output from the K6BEN repeater. It will consist of
From SR Systems:
1 MPEG encoder board
1 DVB-S 23cm minimod
From Downeast Microwave:
1 2330PATV amplifier
From PC Electronics:
1 TVC-4S 70cm downconverter
1 RCV3 channel 3 NTSC demodulator
The concept here is that we receive standard 70 cm AM TV on the TVC-4S channel 1 down to baseband video and audio. Send that into the MPEG encoder and transmit it as DVB-S on 23cm up to the repeater. The repeater will then retransmit the transport stream over ATSC on 33cm.
I'll receive that with my receive station:
From PC Electronics:
1 TVC-9S 33cm downconverter
1 HDHomeRun ATSC tuner
I'm not sure I can configure the DVB-S modulator to key on and off based on whether or not there's good video going into the MPEG encoder. If it is, then I could make the whole thing automatic. But if my experience with the ATSC modulator is any guide, it won't do that, so I'll have to turn the thing on and off myself. But Stefan assures me that the repeater (the DVB-S NIM and minimod combination) can key on and off automatically based on the receive signal.
The repeater will consist of
From SR Systems:
1 DVB-S 23cm receiver board
1 ATSC 33cm minimod
From Downeast Microwave:
1 3370PAHS amplifier
From Ham Radio Outlet:
1 Diamond X6000A 2M/70cm/23cm vertical antenna
1 Comet KP-20 33cm vertical antenna
I'm going to also set up an uplink station for myself. I want to use it at least at first to retransmit the output from the K6BEN repeater. It will consist of
From SR Systems:
1 MPEG encoder board
1 DVB-S 23cm minimod
From Downeast Microwave:
1 2330PATV amplifier
From PC Electronics:
1 TVC-4S 70cm downconverter
1 RCV3 channel 3 NTSC demodulator
The concept here is that we receive standard 70 cm AM TV on the TVC-4S channel 1 down to baseband video and audio. Send that into the MPEG encoder and transmit it as DVB-S on 23cm up to the repeater. The repeater will then retransmit the transport stream over ATSC on 33cm.
I'll receive that with my receive station:
From PC Electronics:
1 TVC-9S 33cm downconverter
1 HDHomeRun ATSC tuner
I'm not sure I can configure the DVB-S modulator to key on and off based on whether or not there's good video going into the MPEG encoder. If it is, then I could make the whole thing automatic. But if my experience with the ATSC modulator is any guide, it won't do that, so I'll have to turn the thing on and off myself. But Stefan assures me that the repeater (the DVB-S NIM and minimod combination) can key on and off automatically based on the receive signal.
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