Sadly though, its me whos shouting 'AARRRGHH!', not the 10m Wispy! I rigged this up again today, this time with the 9t trifilar toroid fitted. Nothing. Then I noticed one of the diodes was backwards! This sorted out, still nothing.
I can see there is some signal getting out of this beast. The spectrum analyser shows the start of a peak with modulation applied, but its many tens of dB down on the levels measurable from the doubler. This is beginning to drive me bloody mental! I just cannot fathom out why this damn mixer wont work! I isolated it from the following driver stage, just in case a fault there was pulling it down, but still nothing. Yet when I mocked this mixer up on its own, it worked? Why will it not work in circuit?
The only thing I can possibly think is that its a phasing issue, I must have the phasing wrong, but it all looks right to me. Im going to have to ask for help with this again from the G-QRP members.
I know I have started Project TennaLady to be a simplified 2nd version of this circuit, but I hate the idea of abandoning Wispy. There really should be no reason for it not working, and ive pestered Roger G3XBM so often about it, and hes always been very helpful, I do feel a bit like i'd be letting him down if I cant make it work.
On a lighter note, the small amount of other radio done today has been good fun. Most of the day has been taken up with church visits as part of my study of local extant war graves (see my other blog http://selbywargraves.blogspot.co.uk/ if your at all interested), which was intended to be a single church visit but turned into five, followed by a bit of gardening. The bit of gardening led to several hours of cutting and blanching parsnips for the freezer!
What I did manage to do though, was to transfer the PSK-20 onto solar power. I have a small solar panel up on the shack roof, about 6" x 18" and rated in the region of 6W, although it is now rather old and inefficient. This feeds a 12v 7Ahr SLAB. I transferred the power cable of the PSK-20 from the main PSU to the distribution block of this system, and switched on. Odd, both LEDs lit? Ah, take the multimeter measuring the charging current out of circuit! Thats better. With the PSK-20 running on stored solar power, I answered a CQ from IP8AAW, an Italian special event, and worked him on first go.
I should get a bit of work on Wispy done tomorrow morning, but I have to be at work mid-day for a secondment interview, followed by Sams parent/teacher evening, then Karate.