wrote:

Hi Paul

I am looking at moving the old CB up to 10meter CW/SSB, One thing I
have never seen is the addition of a BFO circuit to copy SSB and CW.

If you have an AM CB you will be able to receive DSB by the addition of
a BFO. It might work for sending CW, since it is an unmodulated carrier
afterall (some 10m beacons are recycled CB RTXes). You won't be able to
transmit SSB, though!

The radio has a first IF of 10.695 MHz and the next one is 455KHz.

I believe that 455KHz is the place to add the BFO and I think that the
455KHz IF must be mixed with another frequency, say either +/- 1KHz to
get the sidetone.

Correct. You need to inject a 455kHz into the second conversion mixer.
You don't necessarily need to phisically connect it to the circuitry,
over-the-air coupling should suffice.

I don't know if this would work for SSB reception?

Sure it does! (provided your starting point has AM reception).
See my pages http://spazioinwind.libero.it/ik1zyw...re/osc455.html
and http://spazioinwind.libero.it/ik1zyw...c455notes.html for
some operating notes. Please disregard the circuit shown since there are
better solutions.

How about Double-side band modulation, it would have both LSB and USB
but at least it would be interesting to experiment with.

With an external BFO you'll be actually receiving DSB, so no
discrimination between U and LSB. CW stations will appear twice as you
tune up the band. Anyway, since 10m at this time of the solar cycle are
not too crowded (from the European point of view), you should not suffer
opposite sideband interference from off-frequency stations. Making the
BFO frequency agile should overcome your channelized CB limitations.

I haven't been playing with this setup for a while, but it works.

73,
Paolo/Paul IK1ZYW