Radio Meteor Capture

[Karls48 (Karl)]

In one of previous posts I said that I’m not getting any aircraft echoes from TV carrier. That was wrong, yesterday morning I had screen brightness control up and echoes from passing aircrafts were clearly visible.
I’m not registering that many meteors as I thought I would, but I think that’s due to using low gain antenna and pointing antenna at zenith. I think that only quite bright (overdense) meteors are captured. Anyhow, before it become permanently cloudy my video capture setup was not capturing that many meteors either. On some nights only four meteors per night. And that’s with 8mm lens that can see quite big chunk of sky and record meteors down to about 4 magnitude.
Now I’m trying to build some sort of BFO for Tecsun PL600 radio. Its FM coverage is 76-108MHz and there are few TV stations I could monitor in this frequency range. But build in BFO works only on SW band.

[Arizona (Steve)]

Karl, it looks like you fixed the computer problem (?)

I'm just using a cheap commercial TV antenna, pointed toward the transmitter's azimuth, and elevated about 15 degrees above the horizon.

The Colorgramme plot in the preceding post seems to show a good diurnal trend. You could probably detect more meteors by adjusting the detection threshold in the "conditional actions" program.... as long as you continue to see a clear diurnal trend, I would say you are counting meteors.
Some of the guys on the rmob site have "hair triggers" on their systems. They routinely record a couple hundred meteors per hour. However, Chris Steyaert says that anomalous meteor streams become more obvious with lower hourly counts, so I tried to adjust my system's sensitivity to yield counts similar to Chris's.

[Karls48 (Karl)]

Yes the computers are fixed and working again. Computers are pain in the neck – if there is not problem with hardware then the software will play up. But what would we do without them. We had couple of clear nights so I spend some time outside with my telescope.
Geminid shower produced very few meteors so far, at least at my location. During two clear nights we had, my camera captured seven Geminid meteors, brightest –0.8 Mag. That count would hardly show up as meteor shower in Colorogram and it did not.
I consider this radio capture thing as an experiment and I’m not yet convinced that it is working correctly. So far I’m happy that I can see and recognise aircraft reflections and confirm it by looking on flight radar on the net. I also confirmed that the SpecLab is not counting those reflections as meteors. Next I need my camera to capture few Mag –2 or brighter meteors lasting couple seconds in right part of the sky. Then I can compare it with record of SpecLab capture and modify Conditional capture script if needed.
I think that the confidence in the data acquired would increase if one monitors two transmitters at different frequencies that are approximately in same line of sight. And count only reflections that occur at same time. Coffs Harbour and Townswille would do nicely.
I did build VFO and finished up with totally wrong frequency. Used wrong IF transformer did I. Anyhow it was interesting exercise. But I think that my electronic circuits building days are over. My hands shake and I can not see well. So I used old FM radio and coupled IF signal to the Tecsun. It did work – kind of. Frequency drifts and adjusting the signal level is difficult. Too high and Tecsun’s noise blanketing circuit cuts in.
When the finances allows I will look for second-hand communications receiver.