Since I first started experimenting with SDRs, I manage to receive quite a lot of different signal bands varying from HF, NOAA APT, Meteor LRPT, AIS, and all the way to L-Band & C-Band. I was intrigued to try as many of them as I could primarily out of curiosity to experience them myself. But I always had interference issues beyond Broadcast FM band mostly from that same FM stations and other terrestrial signals. So I didn't think much about exploring VHF/UHF bands for a long time.
I made an "End Fed Half-Wave" for 80m-10m bands a few months back and it worked great beyond all my expectations. I was able to receive a wide range of interesting signals including local fisherman chatter on 40m/20m, daily ragchew of the local radio society on 40m, CW weather stations from Japan on 60m, and also a few DRM stations, some as far away as from Romania with it. Recently I was bored listening to more or less the same stuff on HF and finally decided to explore the world of VHF/UHF.
I didn't have a suitable antenna for VHF/UHF bands so I decided to build one myself. I did some research on the best VHF/UHF antennas and there were so many options. I also asked a friend about his thoughts and he suggested I should build a Log-Periodic and try my luck with it. So I got to work...
I used this online calculator to calculate the measurements for my antenna and decided to make it for 100MHz - 950MHz.
I decided to make it entirely out of aluminum because I need it to be sturdy but lightweight. I got some 3/8 inch aluminum tubes for the elements and 1 inch aluminum box bars for the two booms. I was able to make it quite accurately and using aluminum pop-reverts to secure everything in place was a great choice which made it much stronger than I anticipated.
After that, I mounted it horizontally 30 feet high on a pole and scanned through bands to see what can I receive. I was able to receive some encrypted police communications, some faint VHF activity towards the sea, and narrow telemetry beacons which I believe from some CubeSats and at one time NOAA APT and Meteor_M2 LRPT...
Then as I going up in bands suddenly i stumbled upon a much wider signal, which I thought was interference or electrical noise at first. When I switched to 10Msps on my Airspy R2 to see it clearly, I could see two FM downlinks right beside that signal. So I turned to one of them and I could hear the sound of a TV commercial very clearly. As it turned out it was from a local Analog TV station and lucky for me there was already a plug-in for decoding them called "PAL/SECAM/NTSC-TV" which came preloaded with the SDRSharp Community Build. So I launched the plug-in, tuned in to the video signal, and sure enough, as I checked the TV check box it started decoding the video. Then I tuned back into FM audio signal and I had both video and sound...
Unfortunately, there is no way to decode color as of this time, but you can clearly see the color burst subcarrier visible between the vision and audio carriers.
Even though Sri Lanka has been mostly moved to satellite-TV broadcast like the rest of the world, analog TV is still in use. I'm glad I got to receive it before it went extinct forever.