[Amps] Input Network?

Vic K2VCO vic at rakefet.com
Tue Jan 17 23:56:03 EST 2006


Mike wrote:

> L was wound on a T68-2 with six turns of number 18 gauge wire.  The 
> six turns was calculated using Amidon information.

Type 2 material is spec'd for use up to 10 MHz.  A T68-6 would be more 
usual for 28 MHz.  I think about 7 turns would be right (0.24 uh). 
Whether this is the cause of your problem, I'm not sure.

> The xcvr connected and amp. turned on.  When the amplifier was keyed, 
> the xcvr registered a SWR greater than 3 to 1 at 28.3 MHz.  No 
> resonance was seen by a dip in the SWR reading in the xcvr over the 
> 10 meter band.

If the circuit is set up so that you can adjust the capacitors safely 
when the amplifieer is turned on, it would be worth trying.  30 ohms 
seems low for a single tube, but I have no experience with this tube.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco


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