[Amps] 813's

[Tom Osborne]

Hi Colin

When I was using this amp it didn't have a tuned input.  I was using a
Yeasu FT-102 to drive it and it had the pi-net so didn't bother with the
input tuning.

I had a power transformer out of an old Navy TCM-2 tranmitter and that amp
would put out a KW easily.  Might have to dig it out sometime and see what
I've removed from it over the years :-)  73.
Tom W7WHY


On Tue, Dec 22, 2015 at 6:53 AM, Colin Lamb <k7fm at teleport.com> wrote:

> Hello Tom:
>
> That is not true.  It depends upon whether they are grounded grid or grid
> driven.  Grounded grid is a bit cleaner.  The tube is fine as long as it is
> not pushed beyond reasonable limits.  But, that is the same with any tube.
>
> Sometimes they are run in grounded grid mode with no tuned circuit in the
> cathode.  That makes them dirtier, because the "flywheel" in the cathode
> adds up to 5 db improvement in the imd results, just the same as for any
> other tube.
>
> It is still a good tube.
>
> 73,  Colin  K7FM
>