Jerry,
That shouldn't happen with a well-designed 1:1 Guanella Balun, which is
the preferred choice for wide-band, wide-impedance-excusion,
applications. Unlike a 4:1 Guanella balun or 4:1 Ruthroff balun, the
core flux in a 1:1 Guanella balun is not determined directly by the load
impedance / differential-mode voltage.
Here's an example of what I mean by a well designed 1:1 Guanella balun:
http://www.balundesigns.com/servlet/the-98/isolation-choke-balun-common/Detail
73,
Steve G3TXQ
On 09/11/2010 09:20, Dr. Gerald N. Johnson wrote:
Trouble with introducing a balun is that sometimes ladder line is used
to allow a wide tuning range and so there can be a wild set of
impedances and SWR on the ladder line that the balun can't handle from
160 through 10m. One time tuning a tuner with a balun attached, I found
I had tuned the balun so that the tuning and input SWR didn't change
with the ladder line disconnected. That's not healthy for the balun or
for getting a signal radiated.
73, Jerry, K0CQ
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