[ICOM] R8500 & AOR SDU-5000 Spectrum Display Unit ?

[Michael Melland, W9WIS]

I got my recently aquired AOR SDU-5000 spectrum display hooked up to my
R8500 yesterday with no adventures.  While the display is nice, I'm
evaluating whether to keep it or not. I have a couple of questions mainly
for those who may have one of the spectrum display units in use with the
R8500 as well...

I note that strong center frequency signals seems to wipe other signals from
the display.  I imagine this is due to the AGC "overloading" the SDU as AGC
can't be shut off.  SETI has several modifications for the R8500 which allow
selectivly disabling the AGC.  Have you done this and have you noticed
improvement ?

I also note that it seems that a signal at least S4-5 needs to be present to
get a displayed "pip".  I can decode steady stream digital traffic signals
that barely move my S meter but these are lost and not displayed at all on
the sdu... can the IF signal be too low ? (I know the -60 dBm IF output of
the R8500 is at least -10 to -15 dBm lower then AOR receivers)  How about
any improvement with lets say... a wideband low noise MMIC IF amplifier
between the R8500 IF out and SDU IF input ...like the one Ten-Tec sells in a
kit form ?

Any other comments that might be useful are appreciated.

Thanks,

Mike, W9WIS

--
Michael Melland, W9WIS
Winneconne, WI USA
http://webpages.charter.net/w9wis
--
Michael Melland, W9WIS
Winneconne, WI USA
http://webpages.charter.net/w9wis