donroden at hiwaay.net donroden at hiwaay.net
Wed Feb 17 18:19:16 PST 2010
a.. Previous message: [Amps] GS-35B Input
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I think large variations in drive impedence through the rf cycle are
somewhat smoothed out by a low to medium Q input.. BTW, L-C-L (
lowpass ) might be better.
Don WA4NPL
Broad band does not work. The Henry 8 k used one.. and lousy input swr. Henry
also said, DON'T use the auto tuner in ur xcvr. Just put up with the lousy swr.
No fly wheel effect. Instead of 9 x bandswitched pi nets, I use 2 x
broadcast variables + tappedcoil. Caps padded on 160m. FLAT SWR across all
bands. Besttuned input I have used by far. just use small straps, for
taps,which will minimize stray C. A 2 x wafer switch used. Wafer 1changes
taps. wafer #2 pad's C2 on 160m only. Entire coilused on 160m, so 160m pos
of wafer #1, used to pad C1on 160M. I used 6;1 verniers. very FAST band
change..just dial by the numbers. I put wattmeters on both sides+ dummy load.
I was losing a bit too much power on 17 + 15 m taps. [ 220 w in- 160 w out]
So increased uh by a 1/4 turn, then presto, output wattmeter is way up.
Later... Jim VE7RF
Quoting "MIKE DURKIN" <patriot121 at msn.com>:
>
> Just a thought/wondering .. why is it that a broad-band 1:1 torroid
> un-unun not used for the input of a single GS-35b instead of several
> C.L.C. networks ?? Is there not enough fly-wheel effect to keep a
> good linearity??
>
>
>
> Mike
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