I should have added for completeness that it's a 5MHz IF with a 9MHz VFO
mixing arrangement that produces a sideband inversion between 80m and
20m. It also does away with the tuning inversion.
Steve G3TXQ
On 27/08/2018 09:24, Steve Hunt wrote:
Using a 9 MHz IF conveniently gives you 80m and 20m coverage from a
5MHz VFO without the need for heterodyne crystals; however it does
_not_ produce a sideband inversion. What happens is that the tuning
direction reverses - on 80m the RF frequency gets _lower _as the VFO
increases, and on 20m the RF frequency gets _higher _as the VFO
increases.
If the 9MHz IF filter is, say, upper sideband, you'll get USB on both
80m and 20m. It's one of those old "ham myths" that you get a sideband
inversion with that mixing arrangement.
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