Just acquired from an old lady her old CB transceiver. It's rather old;
crystal controlled. Is it feasable to swap out the 27 MHz crystals and
replace them with 10M crystals? Is there a source for these crystals?
And would any major modifications to the rig be required?

Any info would be appreciated (and yes, I hold a Technician class
license).

--
"History is not a spectator sport."-- Dr. Bruce Freeberg --

On Thu, 3 Nov 2011, Padraigh ProAmerica wrote:

Just acquired from an old lady her old CB transceiver. It's rather old;
crystal controlled. Is it feasable to swap out the 27 MHz crystals and
replace them with 10M crystals? Is there a source for these crystals?
And would any major modifications to the rig be required?

So long as it uses a pair of crystals per channel (or one for transmit and
a tuneable receiver), those are the easiest to convert. Just change
crystals, and maybe a slight realignment is needed.

Of course, there was a period when the CB sets were synthesized but via
multiple crystals, mixed together. Those would require more effort to
move to 10M, one would have to figure out what was going on and then
recalculate, and likely realignment would be more important/difficult. I
don't recall anyone writing about converting those.

But if there is a pair of crystals per channel, all you need is to either
scrounge up suitable crystals or go to a crystal manufacturer with
information about the CB set, and they'll grind a set for you. Maybe
costly at this point.

The transmit were usually overtone, the actual frequency being around
9MHz, the receive crystals would be the signal frequency minus the IF
frequency (often 455KHz, but some had a higher IF), and they too were
usually overtone crystals. The good thing is that since you're moving it
to a ham band, you can pick any frequency within the band, the bad part is
that some parts of the band are better than others in terms of activity,
especially for AM, and you need to find a pair of crystals for the
frequency.

There was a period when CB sets often had a tuneable receiver, either with
a few crystal controlled channels for receiver or none at all, and those
would be best, since you can then find any crystal that works and provides
a useful frequency, without having to worry about the receive crystal taht
also has to be the same frequency, but with the offset for the IF.

Michael VE2BVW



Any info would be appreciated (and yes, I hold a Technician
class license).

--
"History is not a spectator sport."-- Dr. Bruce Freeberg --

Padraigh ProAmerica wrote:
Just acquired from an old lady her old CB transceiver. It's rather
old; crystal controlled. Is it feasable to swap out the 27 MHz
crystals and replace them with 10M crystals? Is there a source for
these crystals? And would any major modifications to the rig be
required?

Any info would be appreciated (and yes, I hold a Technician class
license).


Yes, it's quite possible, and in fact, a series of articles was published in
73 Magazine back in the late 70s. Recently, a few kind souls scanned and
made PDF files of the entire run of 73 Magazine. You can Google for 73
magazine download for places tha tthey can be downloaded. Most are Torrent
downloads, and might be the most expedient way to get them. The total
download is nearly 17 GB, so it's not trivial. Single issues range from 15
to 50 MB.
If you can provide the make & model of your CB, I'll check to sse if your
radio was covered. I can extract and email just the article for your radio
if it's covered.

Matter of fact, if you search back through the archives of this list, you'll
find a number of places that you can download from. It was only a few
months ago that this was discussed.
--
David
dgminala at mediacombb dot net

Michael Black wrote:

The transmit were usually overtone, the actual frequency being around
9MHz, the receive crystals would be the signal frequency minus the IF
frequency (often 455KHz, but some had a higher IF), and they too were
usually overtone crystals. The good thing is that since you're moving it
to a ham band, you can pick any frequency within the band, the bad part is
that some parts of the band are better than others in terms of activity,
especially for AM, and you need to find a pair of crystals for the
frequency.

If it's old enough to use crystals, it probably AM only. Aren't technicians
permitted on 10m cw and ssb only?

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM
My high blood pressure medicine reduces my midichlorian count. :-(

On 11-3-2011 20:34, Geoffrey S. Mendelson wrote:
Aren't technicians
permitted on 10m cw and ssb only?

Geoff.


Correct. SSB only (American CB sets are AM unless it has SSB modes as
well)....

USA Tech class emissions (10M) allowed a
J3E Emission (AM, single sideband, suppressed carrier. Single analog
channel. Telephony, voice, sound broadcasting.)

and R3E Emission (AM, single sideband, reduced or controlled carrier.
Single analog channel. Telephony, voice, sound broadcasting.)

Designations can be found at
http://www.ominous-valve.com/emission.txt


N0EDV

On 11/03/2011 12:59 PM, Padraigh ProAmerica wrote:
Just acquired from an old lady her old CB transceiver. It's rather old;
crystal controlled. Is it feasable to swap out the 27 MHz crystals and
replace them with 10M crystals? Is there a source for these crystals?
And would any major modifications to the rig be required?

Any info would be appreciated (and yes, I hold a Technician class
license).



Years ago I actually took an old CB set and bought a crystal for the
lower end of the CW band and used it as a cw transmitter.
Used my HQ-140-X receiver.


Worked fine. When the band was open I worked Japan on it
with an indoor whip antenna!



That was a long time ago and I forgot where I got the crystal
but it could not have been more than few bucks.

On 11-4-2011 02:43, philo wrote:




That was a long time ago and I forgot where I got the crystal
but it could not have been more than few bucks.

Nowadays, a custom crystal could run over $20 from a crystal
manufacturer, so if you need more than 1 or 2 crystals for the
conversion, it's hardly worth it unless you are doing it because you
like to tinker. Probably one of the easiest ways to get on 10M is to
look for a used Ranger/RCI 10M rig or the Uniden HR-2510/2600 or even
the Radio Shack 10M rig. For $75-150 you have a rig with 100 Hz tuning
steps and 25-100W.

Here's a 2600 on eBay that is listed as non-working, but maybe only
because the seller has no way to test it. At least one can see what it
looks like, so if one comes across one at a hamfest...

http://www.ebay.com/itm/Uniden-HR260...em25690e 066d

Radio Shack 10M rig
http://www.ebay.com/itm/HTX-10-Radio...53112715236430


N0EDV

The earlier Radio Shack HTX-100 had a slightly better receiver (quieter)
and had CW as a mode- both different on the HTX-10.

--
"History is not a spectator sport."-- Dr. Bruce Freeberg --

On Thu, 3 Nov 2011, philo wrote:

On 11/03/2011 12:59 PM, Padraigh ProAmerica wrote:
Just acquired from an old lady her old CB transceiver. It's rather old;
crystal controlled. Is it feasable to swap out the 27 MHz crystals and
replace them with 10M crystals? Is there a source for these crystals?
And would any major modifications to the rig be required?

Any info would be appreciated (and yes, I hold a Technician class
license).



Years ago I actually took an old CB set and bought a crystal for the lower
end of the CW band and used it as a cw transmitter.
Used my HQ-140-X receiver.


Worked fine. When the band was open I worked Japan on it
with an indoor whip antenna!

THat's why all those Heathkit Sixers did so well, when the band opened up,
very little power was needed (of course, offset by the fact that the band
wasn't always open). Ten is the same way (though antennas are longer),
there was even that Hammarlund receiver with the CB transmitter built in,
that could easily be used on 10m.


Michael VE2BVW

On 11/04/2011 09:36 AM, Michael Black wrote:
On Thu, 3 Nov 2011, philo wrote:

On 11/03/2011 12:59 PM, Padraigh ProAmerica wrote:
Just acquired from an old lady her old CB transceiver. It's rather old;
crystal controlled. Is it feasable to swap out the 27 MHz crystals and
replace them with 10M crystals? Is there a source for these crystals?
And would any major modifications to the rig be required?

Any info would be appreciated (and yes, I hold a Technician class
license).



Years ago I actually took an old CB set and bought a crystal for the
lower end of the CW band and used it as a cw transmitter.
Used my HQ-140-X receiver.


Worked fine. When the band was open I worked Japan on it
with an indoor whip antenna!

THat's why all those Heathkit Sixers did so well, when the band opened
up, very little power was needed (of course, offset by the fact that the
band wasn't always open). Ten is the same way (though antennas are
longer), there was even that Hammarlund receiver with the CB transmitter
built in, that could easily be used on 10m.


Michael VE2BVW


Don't know why but for whatever reason I still recall the HQ-105-TR

The xmtr was for the CB band but I am sure it could have been usable on
10 meters

Anyway, back in the old days 10 meter AM was great!