[Amps] RF choke switching

[Vic K2VCO]

Because if I do this, the bigger choke will be out of the circuit completely on the high 
bands. My method will leave it there, after the bypass, to provide additional filtering on 
the HV lead to the power supply.

On 6/9/2011 11:12 PM, Angel Vilaseca wrote:
> Vic,
>
> Why not use the vacuum relay to short the big choke? That is what is done on the tank
> circuit when bandswitchig.
>
> 73 de HB9SLV
>
> Vic K2VCO a écrit :
>> I'm planning another amplifier (2 x 4-400A, 1.8-28 mHz) and I was thinking that I would
>> deal with the "RF choke problem" by having two chokes in series. The one nearest the
>> plates will have enough inductance for 20-15-10 meters with no series resonances below
>> 30 mHz. The second will be 1 or 2 mh to provide enough inductance for the 1.8-7 mHz
>> bands. I will use a vacuum relay to connect a bypass capacitor from the junction of the
>> two chokes to ground on the high bands. Of course there will be further bypassing at the
>> cold end of the big choke.
>>
>> That way, both chokes will always be in the circuit to help keep RF out of the power
>> supply but the resonances and distributed capacity of the large one won't upset the
>> higher bands.
>>
>> Is this a good idea or am I missing something?
>

-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/