Vic, If my calculations are correct, YES you should have a good balun. The reactance of the 9 turns is 809 ohms (AL value is 884 mH/1000 turns, inductance for 9 turns should be 71.6 uH) which is more than 16 times the impedance of an antenna feedline of 50 ohms. Greater than 10 times the line impedance is the value I usually use for an effective chokeing action.
73, Don W3FPR > -----Original Message----- > > > I made a simple 1:1 receive-only balun for 160 meters by winding > 9 bifilar turns > of no. 24 enameled wire on an FT37-77 toroid. I connected a > 50-ohm resistor to > the output and my MFJ antenna analyzer to the input. On 1.8 MHz > it shows a > resistance of 50 ohms, an inductive reactance of 1 ohm, and an > SWR of 1.0:1. > > My question is, did I make a 'good' balun? Are there other tests > I should do? > > It's job will be to isolate a receiving loop antenna from its > feedline, to keep > the nulls deep and reduce noise pickup. > _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
