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Re: Further AIDC 3733 adventures


My comments on the bandpass of the filter were presented a couple of days 
ago, and it is broad enough to pass 2.15 to 2.686 GHZ,  as marked. 

I think when you touched the front filter (input), you affected the stub that 
runs from the input to the back filter (output) to near the front filter.  
That would explain the change.  I hope you read the info on the stub I 
presented also.

When I installed the N connectors, before I got the screw in adapters, the 
noise figure had climbed to 19 dB because I had loosened it, so retuning was 
necessary.  Retuning the front filter on my converted units made a 
considerable difference (because they were way out of tune) and the noise 
figure came down to below the specified level.

I have opened up a number of the downconverters, and so far, I have only seen 
the rear filter with a missing screw.  All the units that I have opened have 
had the middle adjustment screw missing from the rear filter, and all have 
had all six screws in the front filter.

I have already sent information on temperature stability, so I won't repeat 
it now.

Bob Seydler
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