[AMRadio] cb to 10 meters


Brian Carling bcarling at cfl.rr.com
Tue Apr 4 11:12:42 EDT 2006


Could you move them up instead by 2.035 MHz and hit 29.000 
MHz OK?

Is there still any AM activity cenetered around 29.100 MHz also?

On 3 Apr 2006 at 22:20, Mike Duke, K5XU wrote:

> Most of the older 23 channel units used a mixing scheme which involved one 
> set of 4 crystals, and one set of 6.
> 
> The standard conversion was to shift the set of 6 crystals up by 2 mhz each. 
> Back then, the crystals were cheap. Now, I doubt you will find them for less 
> than $10 or more each. Of course, you could only change one or two crystals, 
> and you would have a similar number of new frequencies (4 per crystal).
> 
> Moving these crystals upward by 2 mhz placed "channel 1" at 28.965, etc. As 
> someone has already mentioned, this pattern skips right over 29.0, but does 
> fall onto 29.005 for channel 4.
> 
> The later 23 channel pll units, and every 40 channel unit that I saw from 
> the late 70s and early 80s could be converted by moving one crystal upward 
> by whatever amount you wanted to move the rig.
> 
> I have a 1980ish Sharp 40 channel rig converted this way, using the standard 
> 2 mhz upward move, and it works great when the band is open. I bought it 
> from a BC engineer who did a really neat job with the conversion, and it is 
> otherwise unmodified. My first contact with it in 1998 was with a kh6.
> 
> Someday, I may ask someone to add at least one more crystal, 5 khz higher or 
> lower than the one currently in the unit. This will give me 40 more 
> channels, and allow operation on 29.0, 29.010, etc.
> 
> I bought a new pll board for a late 90s Maxon rig, and it fell flat as a 
> pancake. The receiver worked fine, but the transmitter wave form and audio 
> were awful. Having already spent more money that the thing was worth in the 
> first place, I scrapped it and bought an HTX10.
> 
> It's amazing what the converted cb sets will do with the right band 
> conditions. If you have one, drag it out, change it over, and have it ready 
> to go when the band comes back. If nothing else, it will be a wonderful 
> monitor complete with a good squelch circuit.
> 
> 
> 
> 
> Mike Duke, K5XU
> American Council of Blind Radio Amateurs
> 
> 
> 
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