P&H's amplifier used modified 1625's. Suppressor ( or beam forming plates)
grid brought out separately from the cathode to reduce input to output
capacitance in GG operation. This required either removing the base or
carefully drilling a hole on the side of the base and unsoldering the two
wires going to the cathode pin, pulling out the suppressor wire and putting
it into a spare pin.
The plate voltage is similar to that used in 811A amplifiers so it
is possible that someone replaced the sockets in a Gonset and put in
modified 1625's with an filament transformer. An Central Electronics 20A
will drive the P&H LA400 very well. In fact the two are about the same size
and color. They almost look like they are made for each other.
73
Bill wa4lav
At 04:44 PM 9/18/02 -0400, Mike Sawyer wrote:
>Hmmmm,
> I seem to remember that P&H made a '500 watt' (input) amp that used
> highly cheap and plentiful 1625's. If memory serves me, it was a direct
> copy from an article out of QST. There was one slight modification. You
> had to either tie or un-tie the screen from the cathode(?). I've seen the
> article but it would mean rooting through a stack of slightly moldy QST's ;>)
>Mike(y)
>W3SLK
>----- Original Message -----
>From: "Steve Katz" <stevek@jmr.com>
>To: <K6KWQ@aol.com>
>Cc: <amps@contesting.com>
>Sent: Wednesday, September 18, 2002 4:06 PM
>Subject: RE: [Amps] Gonset Amplifier
>
>
>
>
> > -----Original Message-----
> > From: K6KWQ@aol.com [SMTP:K6KWQ@aol.com]
> > Sent: Wednesday, September 18, 2002 1:10 PM
> > To: Steve Katz
> > Cc: amps@contesting.com
> > Subject: Re: [Amps] Gonset Amplifier
> >
> > Yes they did make one with 4 ea 807's
> >
>[Steve Katz] No sweat. I've never seen that one, it is probably
>even older than the GSB-200, I'd guess. 4 x 807 = about 400Wdc input,
>though, or maybe 200W output power. Doesn't seem worthwhile for a 100W
>exciter...maybe if somebody has a QRP station it might help. But I'd bet
>this item would be worth much more in "collector's" value if mated with
>whatever exciter it was intended to go with, to make a station... -WB2WIK/6
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
|