I recently build a Loop antenna for CB radio, or at least i tried.
Its made out of a 80cm diameter Loop of RG58 Coax (shield and core connected at the ends), a Coax stub condensator and a unshielded wire primary loop.
When i put my SDR on it, it seams to have way to much of a wide reception (calculator said it would have only like 40-50khz wide reception band).
When i put my analog power/swr meter on it, it claims to have a SWR of 1.2 and takes about 3.5W of power (compared to my dipole taking 4W).
But when i put the NanoVNA on it to get a more accurate reading of SWR, all i see is a flat line that claims a SWR of about 50.
When i pump up the stimulus frequency up to 300+Mhz i get some SWR dips there down to 1.6, but i assume thats just the Primary loop resonating.
Any idea why i get results on my analog SWR meter but not on the NanoVNA?
Is the NanoVNA maybe putting to few power into the loop to make it resonate?
Hey, i did this! I made a 2m loop and an HF one before. Both showed a narrow dip in SWR about where I expected it, give or take a bit. With a bit of fiddling, I easily got both down to an SWR of <2.
Oh, and general remark, always consult the bible (Rothammel) or the heretical scriptures (ARRL antenna handbook). Both of them could hypothetically be found on those websites that people warned you against, although not the newest versions.