Programmable Oscillator for cb radio

[Techno1]

I was wondering if anyone here has fooled around with the programmable oscillators. I see a youtube video where someone used one for a cobra 29 for extra channels.
Was wondering since crystals are very hard to find and cost too much if one could be programmed for say 11.4758mhz to be used to get high channels on a pll 8719?
Also will it swing enough to give 2+- kc tune for ssb.
These seem to be much cheaper than having crystals made.
The prog-osscillators are a one time program and you can set all the parameters with the program menu.

Here is a page from a company with the programmer.

 

[hpssb]

Local tech we use here has been using those things for a few years now to do exactly that, check out their page on the transmission1 site:

Cobra 29 expansion without crystals - Transmission1

SSB radios done this way have a clarifier range of +/- 1 to +/- 15 kc, you just program the range you want:

New expansion - UPD858 SSB chassis - Transmission1

Loz!

 

[nomadradio]

We tried those oscillators as a band crystal in tube-type receivers. Found the output waveform was rough. This raised the noise level and reduced off-channel rejection.

But when it's injected into a PLL circuit, this should clean it up completely. The module's output only serves to synchronize the PLL's VCO, and isn't injected into the signal flow.

Way later after our first experiment my idiot light came on. If I ordered the module at twice the desired crystal frequency, and divided it by two with D-type flip-flop I would have a square wave with a perfect 50/50 duty cycle.

Never got around to trying it.

73

 

[hpssb]

Tech said the same thing, as long as the programmable thing only injects into the "pll downmix circuitry" then it will be as clean as the original. Asked them about doing a cybernet ssb with the same method and was told not recommended as the unclean signal also goes into the radios rf circuitry and messes things up radio performance wise. Unidens and galaxy ranger stuff not an issue though.

A bit vague (im just a sparky, not a tech) but can ask them for a more technical answer if you want it.

Loz!

 

[Techno1]

thanks for the info i will readup on the mods.

thanks

 

[Techno1]

So I have been doing some searching and reading.
See picture posted on the 4 slot programmable oscillator.
From what I read on the board it will be good for Am but not SSB or FM as you will not be able to vari/open the voicelock/clarifier to slide. Says it will not, but maybe can be used on ssb with no unlock clarifier.

Quote from the company. >also, these oscillators may not be shifted in frequency such as for clarifier or FM modulation).

Dont know if this applies to all programmable oscillators.

Anyone with better info on programmable oscillators please chime in.

 

[nomadradio]

these oscillators may not be shifted in frequency such as for clarifier or FM modulation).

Nope, fixed frequency function only. They're designed to supply the clock frequency to a microcontroller.

73

 

[Holydvr]

Variable-Frequency Oscillator 10K‑220MHz SDR QRP HF Transceiver VFO RF Generator | eBay

Find many great new & used options and get the best deals for Variable-Frequency Oscillator 10K‑220MHz SDR QRP HF Transceiver VFO RF Generator at the best online prices at eBay! Free shipping for many products!

www.ebay.com