|This board replaces the failure-prone 10-Watt
Zener Diode used to bias medium-sized grounded-grid
amplifier tubes like the 3-500Z, 8877 and 3CX3000.
The voltage this board provides is higher than
the original zener. The factory zener voltage was
chosen for SSB operation. This board raises the
bias voltage, vastly reducing the tube
temperature and heat stress associated with AM
operation. The 3-Amp diodes shown are nearly poof-proof
when used with 2 tubes.
|The holes in this board will accept 6-Amp
rated rectifiers, suitable to use with up to six)
3-500Z tubes. This picture shows how the mounting
holes line up with the top two screws on the SB-220
|This one replaces the scorch-prone "Auxiliary
Audio ", or "BA" board in the Tram
D-201A and later versions of the 23-channel D-201.
All the parts have larger ratings, and run at a
lower temerature. The proximity to a large, hot 6L6GC
tube still causes this one to darken a little
after a couple of years' daily use, but the
components all run cooler, and will last longer.
The voltage regulator has a current limit built
in, and a protection diode to prevent damage to
the board in case high voltage "leaks"
into the low-voltage parts of the radio. It comes
with new, shiny pins already snapped into the two
sockets. You unsolder the old, tarnished round
pins from the main audio board, and pull them out
with the old BA board. In goes the new board, new
pins and all.
|This is our outright replacement for the
"Train Wreck" factory-original PLL/Channel
Selector in the Browning Mark IV transmitter. It
covers 32 channels below channel 1 up to channel
96, and does it 5 kHz per click. The RC channels
are all there in sequence, so "We don't need
no steenkeeng PLUS TEN sweetch!". Oh, and by
the way, if you are inside the USA, you are not
even allowed to read this stuff, let alone
operate a radio transmitter that has this thing
inside it. On the other hand, if you are outside
the USA, it's okay to look at this thing, since
you CAN'T buy it here, anyway.
|This is the rear view. The whole thing fits
behind the channel window on the front panel. It
leaves a gaping hole in the chassis deck behind
the meter where the original 'tin can' PLL used
to be. Better air circulation, I say.
|This is an internal keying relay that adapts
"10-meter" ham radios to conventional
ham-type amplifiers. This thing installs inside
the radio. You add a "phono" socket to
the rear of the radio. This board wires to the
jack, and an audio-type jumper cord goes to the
"phono" socket on the rear of the
amplifier, marked "Relay", or "VOX".
Much slicker than a foot switch. It operates from
the INTERNAL transmit voltage inside the radio.
It does NOT
attach to the mike socket, at all.
|A close-up of the version that goes into a
tube-type radio that does not contain 14-volt DC
power. It is powered by the 6.3 Volts AC that
lights the tube heaters. That takes more parts.
|No, It's not for sale. At all.
Besides, it's on 10 meters,
|What a hoot, huh? Besides, who would pay $200
just to throw out their frequency counter and
quit worrying about a Mark III ssb transmitter
being on the
right channel, anyway?
|Yeah, I was hard up for cabinets. I should
put the old analog guts that came out of it on
EBAY and see what happens......
|This one goes PIIIIIing when you key the mike. Fades off in a
pretty convincing way. Fools a lot of 'em.
|A closer view. So you can see the part number
scraped off the chip. I copied this circuit from
one that had no chip number. Fair's fair. If
these ever make it onto EBAY, you can buy one
there and figure out what the chip really is the
same way I had to.
|This board installs inside a Mark III SSB
transmitter, and raises the drive level of WIMPY
sliders, like the Siltronix 80/90, and the Glenn
326-G. This one is probably CLOSEST to prime-time
of all these gadgets. As soon as my courageous
crew of volunteers have installed one in their
radios (and, above all have PROOFREAD my
instructions) this one will appear on EBAY, but
|This board allows the use of a slider on an
older AM-only transmitter, like the Browning Mark
II, or 23S9. Glenn sold a similar gadget to go
with his 326-G slider. Yeah, I have a few, but
the installation instructions for this one just
aren't a high priority, right now. Getting the
crystals for it are still a headache, and an
expensive one at that.