[Amps] Building or Buying a Tuned Input Network

[Gary Schafer]

> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
> Behalf Of Roger D Johnson
> Sent: Monday, January 23, 2006 1:07 PM
> To: Vic K2VCO
> Cc: amps at contesting.com; Tony King - W4ZT
> Subject: Re: [Amps] Building or Buying a Tuned Input Network
> 
> Vic K2VCO wrote:
> 
> > Then, when you have designed or stolen the values, build the networks
> > with mica compression trimmers for input capacitors, fixed silver mica
> > capacitors for the outputs, and T68 size toroid cores.
> 
> I would recommend that the input capacitor be fixed as it set the Q
> of the circuit. I'd put the trimmer on the output to compensate for
> variations in circuit layout and tube input capacitance.
> 
> 73, Roger
> 

Having a fixed input cap and fixed inductance you can not vary the center
frequency of the circuit.

73
Gary  K4FMX