At 09:07 AM 10/5/99 -0400, William L. Fuqua wrote:
>
> Just bought a HB amplifier. A pair of 4-400 in GG.
>It looks very nice but a few things I see need to be changed.
>This one is just fine except for the following:
>
Hi Bill, the following observations are based on using a similar GG 4-400
amp for about 30 years:
>1. Clip on plate caps of the type usually used with 807's.
> You would think a pair of 4-400s would
> have plate caps with fins.
No problem, works fine with adequate side cooling.
>
>2.Tubes are fan cooled on the side and I see nothing providing air
> flow thru the bases.
This works fine as long as plenty of air is moving around the bases. If you
melt the solder out of the tube pins, however, it's not so good.
>
>3. BC-375 tuning unit band switch. This was used in a 100W transmitter.
Typical milatary ratings. Mine has been running for more then the 30 years
I've had the amp. 1200 to 1500 out depending on band, HV, drive, etc. This
switch makes a nearly indesdructable antenna selector switch by the way.
>
>4. No internal shielding. Just a slide on cabinet cover held with
> 6 screws.
If it keeps you from getting electrocuted, it's probably good enough. I
would change that myself, but only because I don't like the looks of that
sort of thing.
Have fun!
73,
Larry - W7IUV
w7iuv@arrl.net
http://www.axtek.com/w7iuv
Amp pix at http://207.108.137.61
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