I followed Joachim, pa1gsj's sensible suggestion simply to divide down my DDS oscillator output (derived from the Si570) in order to place it within the right ball-park for 40m operation. I had a 7474 double D-type flip-flop in the junk box, so I pressed that into service to make a divide-by-two stage. I figured the old TTL device's output would be able to drive the mixer well enough. Here's the additional sub-system, which I knocked up on Veroboard...
After some messing around with tuning, made complicated by the spacing between the WSPR and QRSS sub-bands on 40m (they're almost adjacent on 30m - so close that I can QSY using the VXO - on 40m I have to actually change the DDS frequency between modes), I had the CW and S/MT Hell outputs running "right side up" (unlike last time). Here's a locally captured grab...
At once, the WSPR emissions evidently were on target - here's the first spot, reported by Jorgen, oz7it...
I would be very grateful for further reports / spots.
Tomorrow I'll add a frequency doubling to all my 30m DDS settings to undo the action of the new frequency divider!
...-.- de m0xpd
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