majoco
Stirrer
I have an OCFD 46feet one side and 23 on the other feeding into a commercial (ex a TTFD) balun of unknown ratio which seems to work quite well. Given that my friend invergordon made a dipole for the 8MHz aero band with excellent results I thought I'd give it a try.
Quarter wave at 8.8MHz is about 28ft - knock off 5% for end effect and you get 26.5 feet a side for the dipole and I made a common mode choke from what I thought was a FT50-43 toroid -11 turns each side. Results - abysmal - even at 2100local which usually has signals booming in - checked with the OCFD and all good.
Daylight and dropped the antenna down and made the choke into a 1:1 balun - still no good. Soldered the dipole ends directly to the coax and whoopee - heaps of signals. Perhaps the toroid is not FT50-43 after all.
Ordered an FT140-43 and some miniature coax to make a guanella choke.
Now this is going to be for receive only, so is a choke beneficial? Does it prevent signals/interference being picked up on the outer of the coax and being transferred to the inner? I feed the coax into an active multicoupler (Reaction Instruments 409-2) which has filter and a 50ohm load right at the input.
Any insights would be appreciated.
Quarter wave at 8.8MHz is about 28ft - knock off 5% for end effect and you get 26.5 feet a side for the dipole and I made a common mode choke from what I thought was a FT50-43 toroid -11 turns each side. Results - abysmal - even at 2100local which usually has signals booming in - checked with the OCFD and all good.
Daylight and dropped the antenna down and made the choke into a 1:1 balun - still no good. Soldered the dipole ends directly to the coax and whoopee - heaps of signals. Perhaps the toroid is not FT50-43 after all.
Ordered an FT140-43 and some miniature coax to make a guanella choke.
Now this is going to be for receive only, so is a choke beneficial? Does it prevent signals/interference being picked up on the outer of the coax and being transferred to the inner? I feed the coax into an active multicoupler (Reaction Instruments 409-2) which has filter and a 50ohm load right at the input.
Any insights would be appreciated.