On May 14, 1:07 am, Richard Clark wrote:
On 13 May 2007 16:55:44 -0700, dykesc wrote:

Fixation on BalUns has clouded a simpler solution: wind a choke in
the line and dump the ferrites of suspect quality.

Would you please elaborate on this? Wind a choke where? In the twin
lead?

Sure, twist it candy cane (or barber shop pole) style and wind it
around a liter bottle with at least its width as separation between
windings.


Richard,

I wound the liter bottle choke as you suggested and do believe I'm
getting better results as follows:


1:1 Liter Bottle Choke 4:1 MFJ Balun (tuner
bypassed)

3.94Mhz 57 -j169 14 -j39

7.185Mhz 62 -j212 19 -j48

14.29Mhz 70 -j313 12 -j63

Appears to be a much better correlation to the expected 4:1. Meaning I
can "start" trusting my line input values, though I do believe I can
do better with a properly constructed 1:1 toroidal balun for my input
isolation. Got to order some toroids before I can do this however.

Looks like I'd be better off if I could just lower (zero out) the
capacitive reactance on the twin lead input leaving the resistive
terms alone. Sure wish there was a 1:1 current balun in the tuner. Its
tempting but I don't think I can bring myself to modifying the tuner.
My soldering / desoldering skills aren't the greatest. Its a nice
tuner and I'd hate to muck it up.

I found the thread on testing balun isolation. Still digesting it
though.

Thanks again and 73s
Dykes Cupstid AD5VS