The only way you can do this is to make loop oscillator circuit with 2 or 3 crystals. One crystal of 20.480 MHz, which will give you 26.965 to 27.405 CB band, one crystal of 21.520 MHz for the bottom of 10 meters 28.005 to 28.445 MHz and if you used a 3rd crystal of 21.970 MHz which will give you 28.455 to 28.895 MHz.
The above method is using direct loop oscillator or you could use Doubler loop oscillator method, which would use the following crystals
10.240 MHz = 26.965 to 27.405 MHz
10.760 MHz = 28.005 to 28.445 MHz
10.985 MHz = 28.455 to 28.895 MHz
If you can find the loop oscillator board from a PTBM121D4X chassis the board number is PTOS110A0X this would make the conversion easy to do.
Take a look at this diagram and you will see how it is done.
http://www.cbtricks.com/members/rick_eu ... _Part1.pdf
http://www.cbtricks.com/members/rick_eu ... _Part2.pdf
If you need any more info, let me know.
Rick.
