Message	Date	From	Subject
3190	2009-06-15 06:25:42	Alan Melia	Ceraminc resonator VXOs
Hi, I wonder whether another idea I have used with crystals at LF (136kHz) might be worth trying. If you want 4MHz take a 20MHz and a 24Mhz resonator.....then VXO one and mix with the other. I suspect the tempco is probably about the same, but may be more, but the two resonators should have similar tempcos so the drift should tend to be reduced. I have also produced wider swings like this by tuning one resonator up and the other down simultaneously. 500kHz resonators have used for simple 500kHz TX/RX in the UK 500kHz experimental band were only 3khz of tuning is required. They are certainly adequate for hand keyed morse. Alan G3NYK

Hi, I wonder whether another idea I have used with crystals at LF (136kHz)
might be worth trying. If you want 4MHz take a 20MHz and a 24Mhz
resonator.....then VXO one and mix with the other. I suspect the tempco is
probably about the same, but may be more, but the two resonators should have
similar tempcos so the drift should tend to be reduced. I have also produced
wider swings like this by tuning one resonator up and the other down
simultaneously. 500kHz resonators have used for simple 500kHz TX/RX in the
UK 500kHz experimental band were only 3khz of tuning is required. They are
certainly adequate for hand keyed morse.

Alan G3NYK