[Elecraft] Balun for K-1

[James R. Duffey]

Tom - I am familar with this work, and have often quoted it in the past. It
is a definitive work.

I think it is unecessarily complicated for the task at hand. For the use
over the short frequency span of interest to a K-1 4 band module user, 7 MHz
to 21 MHz,  a simple coiled coax choke balun, 6 or 7 turns should provide
adequate choking reactance. It is simple, can be made in minutes, and is
effective. With it you can be on the air in minutes. The numbers you quote
indicate the effectiveness of the simple coiled balun, the balun in column
5, 8 turns sceamble wound into a 6 5/8 in coil, has a peak choking reactance
of 8530 ohms and a 200 Ohm choking reactance bandwidth (recommended by
deMaw) from 2 MHz to 16 MHz (an 8:1 bandwidth. There are those who think a
200 Ohm reactance bandwidth is inadequate, so the 500 Ohm choking reactance
bandwidth is from 3.5 MHz to 10.5 MHz, still a respectable 3:1 ratio.
Winding a coiled coax choke balun as I suggested should be adequate for the
4 band K-1, which was the application I was addressing. Other applications
may require more care. and a better balun. When improvements are made to the
antenna system at a later time, the balun can be upgraded. But to get on the
air quickly with a minimum of fuss and acceptable performance, the coiled
coax balun is hard to beat.

The posting was in keeping with my QRP KISS (Keep it simple stupid) policy.
I find the KISS policy keeps me out of trouble and on the air more than
pursuing optimum (and oftem more complicated) solutions. Don't get offended,
the stupid in KISS is not meant to apply to anybody but me. - Dr. Megacycle
KK6MC/5 
-- 
James R. Duffey KK6MC/5
Cedar Crest, NM   DM65