Hello, I know this is not technally ADSB related, but I know some of you on her are very knowledgeable on antennas and the like, but does anyone know how to find out what frequency an antenna is built/tuned for without an analyser?
As I found what looks to be a loaded coil one, on a walk this morning. Total length from top to bottom is 28cm, top to top of coil is 17.6cm, coil top to bottom is 3.6cm, coil diameter is 1cm, bottom of coil to bottom of antenna is 6.8cm and wire diameter is 1mm.
Or even if you know of any sort of website with a calculator like you get for the 1/4 wave spiders, Dipoles ect that I could type the measurements in would help.
Assuming you have an unfiltered SDR, you can use that as your analyser.
If you put your antenna at the focal point of a dish (difficult with a long antenna, but somewhere near the focal point)
Point the dish at the sun and do a broad frequency scan - the sun is a good noise source.
I can’t think of another technique that won’t involve some additional investment.
Next step would be a BG7TBL “nose” source (a typo on the PCB).
