Gary Schafer wrote:
>
>
>Ian White G/GM3SEK wrote:
>> Phil Clements wrote:
>>
>>>>>I believe I've read on here before where some owners have built
>>>>>MONO band
>>>>
>>>>amps but powered them all from a single power supply. So, one power
>>>>supply deck and TWO RF decks. It has been suggested that I use vacuum
>>>>relays to switch between the two RF decks. I was hoping to have them both
>>>>run in standby at the same time. I obviously do not know enough and am
>>>>therefore here seeking guidance. I will only operate one amp at a time.
>>>
>>>Frank Donovan, W3LPL is probably the world's best source of info on
>>>this type of lash-up. His multi-multi contest station, as I recall,
>>>had amps for each band, with only one power supply. It may still be
>>>in operation.
>>>
>>>No, you don't need any relays to switch HV; just excite the amp you
>>>want to use. I would highly recommend HV glitch resistors in each RF
>>>deck, and also in the power supply.
>>>
>> A separate resistor in each amp would reduce interaction and voltage
>>drop, but a resistor is needed in the power supply as well, to handle
>>the situation where one of the B+ leads shorts to ground.
>> Each amp also needs its own separate anode and grid current
>>metering. A Triode Boards customer is looking at this right now, and
>>I think I've second-guessed how Frank must have done it, with
>>isolating diodes in the B-minus return.
>>
>What about if you don't light the filament on each amp?
Workable for a single station, and for directly heated tubes; but in a
multi-multi station, each amp needs full real-time metering.
--
73 from Ian G/GM3SEK
http://www.ifwtech.co.uk/g3sek
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