[Elecraft] Balun question

Vic Rosenthal vic at rakefet.com
Wed Apr 6 18:39:22 EDT 2005


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.

The RANT feature of the K2's 160-meter option has made it possible for me to use 
a ferrite loop which is only 21 inches (53.3 cm) long and has a s/n ratio much 
better than my inverted L transmitting antenna, even without the balun.  I'll 
put details on my website after I finish testing it.

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco



More information about the Elecraft mailing list