[Amps] 833A GG

[Mike Waters]

On Mon, Jan 26, 2015 at 9:46 AM, Fuqua, Bill L <wlfuqu00 at uky.edu> wrote:

>   But as far as the 833, I  see  no advantage of running them in GG due to
> the grid plate capacitance.


Yup, that's the main problem, Bill.



> Either a single or two in push pull would be better.


Well, a single 833A won't do the legal limit without pushing the envelope.
And the trouble with P-P is that the old parallel-tuned link coupled output
circuit doesn't meet today's FCC harmonic suppression standards. That's why
we use L- or Pi-networks today. (But I'll bet you knew that. :-)



> I am not aware of any hams getting good results on 10 meters however.


With P-P, I think it might be possible; some mfg. data sheets I've seen
claim 40 to 70(!) MHz at full plate voltage and current. Practical, well,
that's another matter!



> Some have been built for 80-20 meters but the output drops a bit on 20.
>

I thought that would be the case on 20. When I find a suitable neut cap,
I'm going to try 20.

Have you --or anyone else-- ever seen an amp successfully completed with
two 833As in parallel? I never have, and that's part of the reason I
decided to do it. It was an interesting challenge.

73, Mike
www.w0btu.com