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 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)

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

On Apr 19, 9:28 am, (Michael Black) wrote:

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.

In the early sixties I ordered one of those cb kits from an
electronics magazine. It consisted of a crudely punched chassis, a bag
of parts and a schematic. I never did get it to work.

cmdr buzz corey wrote:
On Apr 19, 9:28 am, (Michael Black) wrote:

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.

In the early sixties I ordered one of those cb kits from an
electronics magazine. It consisted of a crudely punched chassis, a bag
of parts and a schematic. I never did get it to work.

I thought building a kit CB transceiver was illegal due to the type
acceptance issue?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey ) writes:
cmdr buzz corey wrote:
On Apr 19, 9:28 am, (Michael Black) wrote:

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.

In the early sixties I ordered one of those cb kits from an
electronics magazine. It consisted of a crudely punched chassis, a bag
of parts and a schematic. I never did get it to work.

I thought building a kit CB transceiver was illegal due to the type
acceptance issue?

Certainly Heathkit got around the issue with their full blown CB set(s)
by having the transmitter arrive as a preassembled module.

But I thought there was a CB "Benton Harbor Lunchbox" for a while,
and I can't imagine they would have a module for such a low end
unit.

So perhaps the type acceptance came a bit later? I can't remember (not
that I was aware of such things at the time, but I have read lots
of back issues of magazines).

In the very early days, there was equipment being made out of people's
garages. So either the rules were more lax then, or from the outside
there were companies selling things that weren't legal.

Michael VE2BVW

"Scott Dorsey" wrote in message
...
cmdr buzz corey wrote:
On Apr 19, 9:28 am, (Michael Black) wrote:

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.

In the early sixties I ordered one of those cb kits from an
electronics magazine. It consisted of a crudely punched chassis, a bag
of parts and a schematic. I never did get it to work.

I thought building a kit CB transceiver was illegal due to the type
acceptance issue?
--scott
--


It may be now, I don't know. At one time Heathkit put out a kit called a
CB-1. This was a simple CB and not at all like the one being talked about.
There may have been others, but this is one I know of for sure.

(Scott Dorsey) writes:

I thought building a kit CB transceiver was illegal due to the type
acceptance issue?
--scott

There was a period, long, long ago, when CB was young, and I was not
yet but a leering glance, that building CB gear was okay.

It stopped being okay before the explosion of the mid-70s.

--
Lawrence Statton - m s/aba/c/g
Computer software consists of only two components: ones and
zeros, in roughly equal proportions. All that is required is to
place them into the correct order.

Lawrence Statton wrote:
(Scott Dorsey) writes:
I thought building a kit CB transceiver was illegal due to the type
acceptance issue?
--scott

There was a period, long, long ago, when CB was young, and I was not
yet but a leering glance, that building CB gear was okay.

It stopped being okay before the explosion of the mid-70s.

There were a number of kits as I remember. Heath had several, as did
Allied (Knight Kits). These could be at least as sophisticated as the
mid-range factory units of the day.

jak

Many years ago I worked in a Motorola service shop. One
day a gentleman came in with a Heath CB kit he had built
and wanted to know if we could fix it for him. I explained
our minimum charge and hourly rate and he agreed to an
hours work to see if we could get it running. Several days
later we had a lull in the important work so I pulled the
CB off the shelf and opened it up. I was astonished! All
component leads were full length! He hadn't trimmed a one!
It must have taken him hours of carefully bending leads so
he could get it into the case without shorting anything.
Needless to say, virtually every stage in the RX was
oscillating. I did a bunch of cutting and resoldering and
finally got it working. I wish I had a picture of my face
when I pulled it out of the case!

73, Roger


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