[Amps] Tuned input for 2 x GS 31 B

[Peter Voelpel]

Geert,

what capacitance did you take into your calculations
for C-tube-input, choke and strays?

73
Peter



Von: "Geert Hofman" <Geert_Hofman at Jabil.com>
An: <amps at contesting.com>
Gesendet: Dienstag, 3. Januar 2006 19:12
Betreff: [Amps] Tuned input for 2 x GS 31 B


> Prepared the tuned input circuit based on a Q of 2 for all contest bands
> ( so 50 to 25 Ohms impedance matching ) , and tested it out with my MFJ
> analyser, but found out that I was way too high on nearly all bands
> (except 80 meter where I was pretty close). Now I might have been
> mistaking possibly by 1 winding on the cores, but certainly not more
> than that. I am using hermetically sealed Siemens (HF) relays for the
> switching of the bands. To give you an idea my tuning on 10 meters
> turned out at 40 + Mhz with a resistive 25 Ohms loading!!. I had to
> decrease my initial cap values both on input and output  from about 120
> pF to about 20 pF...