My analyser Mk2 is already under construction and will aim to provide masses
more features, greater coverage, and improved dynamic range performance.

Why not go for the minicircuits +14dBm high level mixers ? ... their quite lossy
(around 9dB loss) but that can be over come. They do need a fair bit of LO
drive though (50mW) but that's no real problem these days, a couple of +18dBm
MMIC's (ERA's etc) in push pull mode should guarantee that level of power and
hopefully give you 3db more than needed so you can use 3dB pad's around the
mixer.

Clive