"Fred McKenzie" wrote in message
...
A crystal for 5 MHz would be OK - 4
MHz would come up at 1000 kHz on the dial.

Peter-

With high-side injection wouldn't the dial tune backwards? 4000khz would
appear at 1000khz, but 4500kHz would appear at 500khz on the dial.

Yes it would. But it's no great hardship and improves one's mental maths!

If Tony can adjust to the backwards dial, I agree that a 5000khz converter
crystal would be the better choice, since it might be easier to filter out
images at 6000khz than images at 2000khz when using a 3000khz crystal.

Agreed. I have a h/b receiever that tunes 1.6 to 4.0 MHz as a tunable IF.
There are xtals every 2 MHz in its front end converter. Using a 2 MHz xtal
for the 4-6 MHz range hardly worked at all, and it was better to switch in
the 6 MHz xtal and accept backward tuning.

Another benefit is that 5 MHz xtals seem to be more obtainable than 3 MHz
xtals.

73, Peter VK3YE


73, Fred, K4DII