Suzy wrote:
Looking for a website that gives comparative performance of diodes (max
frequency for UHF use)

A recollection from decades back are the 1N21, 1N23, 1N32, 1N53, 1N60, and
1N78 point-contact silicon diodes that were used as mixers well into the
microwave spectrum. Googling 1N23 produces 8000+ hits... including a
"Simple 2.4 GHz SWR Meter": (http://www.qsl.net/n9zia/24swr/index.html). I
see RF Parts (http://www.rfparts.com/) sells the 1N21 and 1N23.
MicroMetrics (http://www.micrometrics.com/) makes them, as well as various
schottky diodes suitable for sampling.
73,
Bryan WA7PRC