[Elecraft] OT: balun rating exceeded

[Stuart Rohre]

Brett,
There ARE kilowatt baluns, but the balun probably will not help a G5RV due 
to the fact it is resonant on 20 as a gain antenna, and somewhat of a 
mismatch on any other band.  In fact, you would be better off running open 
wire line all the way to a Tee tuner, then using a ferrite bead 1:1 balun 
after the tuner and before the balanced line, ONLY if you have any RF on the 
tuner or rig chassis.  From what you say, in your case, location has worked 
to mitigate imbalance and you do not need a balun if you do not see stray RF 
effects.

Look to suppliers such as <thewireman.com> for high power balun kits if ever 
you need one.

A balun is not very lossy to your signal, UNLESS it gets saturated.  A bead 
balun on coax should only be handling minimal power from stray pickup to 
outer of the coax shield, and thus will not be saturating, to the extent 
other baluns might.

However, G5RV and others analyzing his antenna have remarked that the balun 
at junction of parallel line and any coax to shack may show no benefit from 
a balun.   Originally, the G5RV was done without a balun.  It theoretically 
"looks" like it would be necessary, but even the venerable balanced line end 
fed Zepp only shows 10 per cent imbalance when end fed, per L. B. Cebik's 
analysis.  (see www.cebik.com for extensive antenna info.)

If the balun materials are big enough, they are not lossy to a significant 
degree, when appropriately applied to specific impedance transformation as 
well as balancing.

Loss in a balun can be noted by seeing if it heats up.
No heating from ambient to full power says there is no loss at the balun. 
In some applications, critical lengths of line can place the balun in a 
point of too high SWR, but proper design puts the balun at an appropriate 
point.

Stuart
K5KVH