[Premium-Rx] 590H Filters?

[ToddRoberts2001 at aol.com]

In a message dated 1/6/2009 7:55:51 P.M.  Eastern Standard Time, 
_cntaty at wcc.net_ (mailto:cntaty at wcc.net)   writes:
To all:  

I have tried to get information about the 590H from Harris...nada!!   They
won't even talk about it and will not give you any hints.  I have  two of the
items and they are good receivers except for this "painus in the  a_us."  The
unit was designed for frequency hopping service and its  reputation indicates
it is well designed for this and most other services: it  is also much
heavier than the 6790 RACAL series.  Frankly, I prefer  RACALs over the
Harris but some people like Chevys and some like Fords.   I worked at Collins
(Dallas) way back in the Sixties and during that time  made friends with many
people in the industry...some still at Harris and  neither I nor any of my
friends from that period have been successful with  Harris (collectively) in
getting the necessary information that would a allow  a modification of the
receiver such that it will perform as Todd's  acquaintance's.
 
Frankly that is not a bad way to proceed and If Todd could come by  the
information in a more graphic form, I, for one, would give it a  try...it
doesn't seem too hard at first blush!  
 
Bill
W5STP
_______________________________________________________________
 
Hi Bill,
John Reed KA5QEP is  the one who built his own IF boards for his RF-590. 
Actually he built two boards  - a Pre-IF board with set of filters and a Post-IF 
board with another set of  filters. He found that he was able to improve the 
S/N ratio of very weak signals  in the narrower bandwidths by cascading two 
narrow filters in series. He found  the improvement wasn't too much in the wider 
bandwidths so he concentrated on  cascading  narrow cw filters.
A few years ago he sent me a collection of notes on his homemade IF boards 
with  schematics. I made pdf copies of them and would be glad to email you 
copies of  them if you are interested. I was planning to make up my own custom 
RF-590H IF  board someday and it is one of those projects I haven't gotten around 
to yet.  John's notes should be enough to show someone how to do it. Someone 
could make  just one IF board if they didn't want to fool with having to use 
two in series  if they didn't really need to cascade  filters.
I haven't corresponded  with John Reed in about a year. I am sure he would be 
glad to help with any  advice or info he still has.  Here is his last email 
address of a year  ago:
 
_jreed at alum.mit.edu_ (mailto:jreed at alum.mit.edu)  
 
73 - Todd WD4NGG

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