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".

The mixer crystal is a puzzle: it implies an IF in the ~3.3MHz range,
which I've never seen before. OTOH, if it was made for 10 Meter ham use,
a 29.305 MHz crystal and a 455 KHz IF would work out to either
29.760 or 28.850 MHz, and only the lower frequency is in the 10 meter
band. It might have been a custom-made unit for CAP or other use on
29.76, but I don't have any experience with those.

I'm going to guess that you have a CB set that was modified for either
10 meter ham use or for some quasi-government use on 29.76.

HTH.

William

(Filter noise from my address for direct replies)