[Elecraft] Balun with a G5RV?

[Charles Greene]

At 07:42 AM 4/21/2002 -0400, Tom Crites wrote:
>I am using a G5RV antenna with my K2 (with KAT2 tuner) fed with 60 feet of 50
>ohm coax.  I've been trying to figure out if I need a balun between the 450
>ohm ladder line and the coax.  Will a balun improve the antenna performance
>or just help keep RF out of the shack?  My existing setup with no balun is
>marginal on 10 meters.  With the G5RV I've seen suggestions just needing just
>a tuner, to a 1:1 air-core choke balun, a 4:1 balun, 75 ohm coax,...., etc.
>
>73,
>Tom,

G5RV, Lou Varney, recommends a 1:1 air wound balun using coax or else 
none.   There are some described in the ARRL handbook.  His reasoning was 
the balun on a ferrite or powdered iron has high losses at high 
impedances.  Sevick, in one of his books, recommends a 2:1 balun, but they 
are hard to come by and make.  I use a G5RV with a 1:1 commercial balun at 
the intersection.  It works well.  I recently did a study to try to 
determine which balun was the best for the G5RV.  It has a low impedance on 
20 and 80 but a high impedance on most of the other bands.  My conclusion 
was that a 1:1 balun was about as good an any, and Varney, after all these 
years, is still right.

73, Chas, W1CG