Saturday, August 8, 2009

Test result

Since I didn't give much advance notice for this test, I wasn't expecting much response. Really, what I was going to do was to see if I could receive anything with the HDHomeRun being driven by the TV antenna feeding into a TVC-9S downconverter.

Well, from Cañada College, I was unable to even tickle the signal strength meter in the HDHomeRun - it couldn't tell the difference between the transmitter being on or off.

But I didn't give up. I went by a spot I know about in the Cupertino foothills - near Miles' old house (for those of you who know Miles). From there, I set the transmitter up again and this time I was able to bump up the received signal strength by 10 points, and make the signal quality gauge go up from 0 to about 5 at one point.

That's a path length of a little over 6 miles (compared to almost 19 miles for Cañada). A LR analysis of the path between Cañada College and my house compared to the Cupertino hills QTH and my house shows a path loss difference of 12 dB or so. The predicted field strength for the Cupertino hills QTH is 76.7 dBµV/m and for Cañada is 65.21 dBµV/m.

Keep in mind that's with a receive antenna pointed the wrong way by about 45 degrees and tuned to a band almost double the wavelength. In other words, I'm relatively sure I was paying quite a receive penalty with that setup. But I still managed to tickle it.

I have a proper 33 cm loop Yagi antenna on order, but it hasn't arrived yet. When it does, I'm confident that I'll be able to pull in the signal from the Cupertino QTH at least.

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