[VHFcontesting] Bought a 24GHz gunnplexer...now what?

[Steve Kavanagh]

There's a few (old!) articles on Gunn oscillator gear at http://www.kwarc.org/10ghz/index.html which may help a bit. I still have a couple of 24 GHz rigs based on the RF portions of Kustom speed radars, which have been pressed into service regularly in various contests for many years.  But at least in this area there is zero regular activity on wideband FM now, so two rigs are essential, one to keep and one to lend to a friend.

There were a few peculiarities to these rigs.  One was that the warm-up drift was greater than the electronic tuning range of the oscillator, which necessitated using a tunable IF strip.  Second was that they came with circularly polarized horn antennas with an odd circular waveguide interface which was not amenable to replacement with dishes, making serious dx rather difficult.

I managed to find a surplus cavity frequency meter, so I was able to set my two oscillators to frequencies about 30 MHz apart near 24.125 GHz  (I think they were nominally 24.120 and 24.150 GHz but the rigs are lent out at the moment so I don't have access to the frequency labels).

73,
Steve VE3SMA