[Milsurplus] Powering the TBW-4

[howard holden]

Dave, just outta curosity, what do you use to modulate the GO-9? I only use mine on CW 80 thru 17M, not interested in phone but I'm curious. Reasonably stable, with 1400V on the plate of the 803 and just 360V regulated on the 837s and 803 screen, I get about 115W on 40 and 80, maybe 90 on 30M, 70 on 20M, and 60 on 17M. I key the center tap on the 12V filaments, (so I'm actually keying the oscillator and IPA). The final runs all the time, draws about 50mA at idle and 120mA key down, by the time I get to 17M maybe 100mA.

Thanks and 73,

Howie WB2AWQ 

________________________________________
From: milsurplus-bounces at mailman.qth.net <milsurplus-bounces at mailman.qth.net> on behalf of David Stinson <arc5 at ix.netcom.com>
Sent: Monday, August 26, 2024 9:24 AM
To: milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] Powering the TBW-4

I know I'm late on this.
I really like my GO-9 even if it did try to kill me ;-).

Couple of things:
The filament voltage meter is designed for 800 cycles.
It reads a little over a volt high on 60 Hz.  i.e. with
10 volts on the 803, the meter will read just over
11 volts.

My GO9 is very frequency stable and clean-keying
even up to 20 meters.  This may be because I designed
the B+ and B++ supplies with larger currents in the
equalizing resistors across the  (50K at 5W across each
vs 100K or more typically), or because it's a bridge
rectifier with the transformer center tap used
for low B+, or that mine is grid-block keyed, or what.
But it is very stable with just a few minutes warm-up.
This morning, on the 3890 KC Saturday Morning net,
at power-on it was at 3890.7 KC and at a half hour
when I next checked, it was 3890.00 with no knob
fiddling.  It stays there until the net ends.
Not quiet that good on 20, but still exceptional
for what it is. Needless to say, I'm happy with it.

Grid-block keying -160 V is developed by rectifying
line voltage through a Dow Key relay coil, keyed
to ground, thus providing grid block bias and
antenna switching with one solution.  I know
the objections to the AC line power, thanks.

73 Dave AB5S