[Lowfer] Can a DDS replace the crystal in an oscillator ??

[Jim]

> A 23 year old radio with a crystal that goes haywire...

Most DDSs are going to use an oscillator module as the basis for clocking 
things and their stability isn't going to be any better (ppm-wise) than that 
oscillator module. One thing you might think of doing is ordering an 
oscillator module programmed for the frequency you need and dropping it into 
the circuit.

But, having said that, I suspect that it will be like a balloon--push in one 
place and it bulges another. I assume the crystal you're talking about is the 
local oscillator (LO). Even if you get it stable, you will likely find that 
the beat frequency oscillator (BFO) wanders a bit.

I've got a new job and I'm in Chicago more than I'm home these days, so my LF 
tinkering has kind of come to a stop. But I have to admit I'm biased towards 
QRSS because it's easy on the transmit and receive ends.

73 de
Jim W4JBM

Receiver - Ten Tec RX320D
Antenna - Butternut Vertical (SW) and mini-whip (LF)
Location - Bowdon Junction, GA  USA (33.6581,-85.1249 EM73)

http://www.hamuniverse.com/w4jbm/

"With a soldering iron in one hand, a schematic in the other, and a puzzled 
look on his face..."