Joe,
I imagine your right. That's the problem with triodes if you want to parallel
them. One needs to go to tetrodes or pentodes for smaller output C. I have
built some though for 10 meters that didn't use a Tune C. The output C was
enough that load C was all that was required (output C equalled what tune C
would have been). This was to be used over a narrow bandspread of about 50 kHz
though. One could add some L before tune C making a L-Pi circuit, which has
been done before. However, when it get's into paralleling that many, it would
most likely be cheaper, and less complicated to go with 1-2 larger tubes.
Best,
Will
*********** REPLY SEPARATOR ***********
On 7/23/06 at 1:37 PM crawfish wrote:
>I have an article using 6 of the 811A's in parallel for 160 meters from 73
>Magazine, early 1980's. I would imagine the output capacitance of more than
>4 would be too much to tune the plate circuit on say, 15 and 10 meters.
> Joe W4AAB
>----- Original Message -----
>From: "Hsu" <Jbenson@sohu.com>
>To: <amps@contesting.com>
>Sent: Sunday, July 23, 2006 6:05 AM
>Subject: [Amps] The maximum amount of 811As and 572Bs in parallel
>
>
>> Hi,
>> I have seen some schematic diagram of amplifier, I found that the
>amount of 811As and 572Bs no more than four, Coud someone can tell me how
>much maximum amount of the tubes in parallel?
>> Thanks!
>> 73! Hsu
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>
>
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