William Warren ") writes:
Jim wrote:
I recently won a HOMEBREW 23 channel CB receiver. Yes I know it's
not a real boatanchor but given that it has 11 tubes plus several
diodes , I thought I'd ask about it here. It looks very well made.

I was hoping that some one would recognize it by tube line up. I just
looked at it and haven't started drawing the schematic yet. It has the
following tubes, 6EH7 (the RF amp) , 12AT7, 12AU7, 6BN8, 6HR6, 6BA6,
6BE6, 6GX6, 12AX7, 6AQ5, and an OA2. It has 6 RF and IF
transformers.

The antenna is connected directly to a transformer with the RF amp
feed by a cap off the secondary. The first oscillator(?) Uses a 29305
Kc crystal. It has a "S meter" and what I suspect is a meter adj. pot
on the back. There is a octal socket on the back labeled transmitter
that has two lines jumped as well as a voltage divider with a large
electrolytic to ground in the middle of the divider.

The tuning cap is three section with one section switched by a
control on the front panel. The tuning cap is driven by a very nicely
home made dial cord mechanism with a heavy flywheel. So far I have
figured out the RF and audio gain controls. The other two front
panels pots function are a question as well as the functions of four
multi section toggle switches. With the filter caps being bad. I have
not powered it up for more than two minutes.

Does anyone remember a home brew rig with these features HAM or CB? I
would like to find a schematic if possible. I looked at the HBR site
and it doesn't seem to match anything there. But given the limited 23
channel coverage plus channels A-D it looks like it's from the late
1960's or real early 1970's .

Thanks

Jim


Jim,

I'm very surprised to hear that someone would homebrew a CB rig: I'd
guess it's a commercial unit without the front plate unless the
workmanship is definitely "homebrew".

IN the sixties (and early seventies), it was common for the hobby
electronic magazines to treat CB as a hobby. This was especially so
for "Electronics Illustrated" that had quite a few construction articles,
going from simple to quite sophisticated. So you could build a panadaptor
to check out the adjacent channels, and a receiver to monitor channel 9
(when it became a designated emergency channel) and even a grid dip
oscillator for "Class E CB" up at 220MHz, even though that service
never came to pass.

THere is nothing unique about the description. I can't recall seeing
much in just tuneable CB receivers in the hobby magazines from that
time, but it sounds like a relatively generic receiver (and he did
say receiver, not transceiver).

If it is a CB receiver, there's nothing to guarantee that it was
built from a description in a magazine article, or that it's a direct
copy of something. Someone could have made it up, or copied something
else with mods for CB. Afterall, no matter what the unit is, someone
has to create a unit before they can write it up in a magazine, so
something can exist without a magazine writeup.

And given that he says it's a receiver, if it was a commercial unit
the pickings are slim. I can think of only one manufacturer that made
a standalone CB receiver.

Michael VE2BVW