On Mon, 07 Mar 2005 22:16:01 -0500, Ken Scharf
wrote:

gudmundur wrote:
This is on a 10 gig receive setup. There is no LNFE, just antenna
to mixer direct couple in a balanced waveguide mixer assembly.
The question is, if I remove the 1N23E/1N23ER pair, and go with a
balanced set of schottkey microwave diodes, this would allow me to
drop my local oscillator injection perhaps 6db. Will I see any
increased sensativity, or should I just keep the 1N23 setup?


wow, those 1N21/23 diodes are stone age! They are Germanium diodes
and usually have to be biased for lowest noise, best conversion
figure. Also when used in cavities, the diode itself forms part
of the coupling network. The letter in the diode part is a measure
of noise figure, the higher up in the alphabet you go, the lower
the rated noise figure. BTW those diodes a dated from the
1940's!

when the devices were too old, they couldn't use them, and called them
1N451(?), and had modern diodes for another 50 years


---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm