Help with amplifier vs TS-820

Dave gekko95 at IX.NETCOM.COM
Thu Sep 4 18:09:12 EDT 1997


Hi all,


I feel rather stupid asking this, but I'd rather sound stupid here
than in a newsgroup!!!

I have just acquired a homebrew 1KW amplifier using a pair of
813's.  Was built by a local engineer and is quite a piece of
homebrew boatanchorism!  MASSIVE power supply, and overdesigned
throughout.  I am assured it works fine, and I believe that to
be the case.  Very nice unit - he even used Heathkit variables
from the SB-220 and rated all components as if the amp were
running 2kw, all in a machined aluminum 100% homebrew cabinet.

My question, and reason for aprehension, is I've never had an
amplifier before and have no clear picture of how best to tune
up with it. (Didn't ask when I bought it).

My rig is a TS-820 with 6146 outputs, and the amplifier has a
broadbanded un-tuned input, with between 100 and 200 ohm
input impedance (so I was told when I bought it).

To tune up, would I first tune the 820 to full output into a
dummy load  and then put the amp in line and tune the tank
for full amplifier output?  This would mean 100 watts of
drive before the amp tank would be tuned.  That doesn't
sound right to me - sounds like a recipe for molten tubes.

Or put the 820 in 'tune' with a very small amount of drive
and actually tune into the amplifier, followed by then
tuning the amplifier tank, followed by then going to full
drive?

Or something else entirely?

I guess what I really need to know is who's tank gets dipped
first, and at what drive level, and into what load (dummy or amp input).

Oh, BTW, the amplfier was only $50 with fresh tubes and
2000v 500ma power supply!  This was a very generous fellow
who has built a multitude of transceivers and amplifiers
over the years.  Thank goodness I didn't have to ship it !!

Thanks for the reply,


Dave WB7AWK
Tacoma, WA




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