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Re: AIDC 3733 Stub



Remember:  If there is going to be any attenuation in the IF path, it is
better to put it just before your receiver than in the downconvertor.
That way it will also attenuate any leak-through of local 2-meter
signals into the feedline.

Given this, it makes to disable the stub.

Doug
NA1DB

At 05:52 PM 4/7/01 , BobsImsai8800@aol.com wrote:
>Joe,
>
>The stub is more of a measurement problem than an operational problem.  When 
>people have measured the gain or the response, they can see the hole in the 
>response in some downconverters at 2400 MHZ.  Some downconverters have the 
>hole somewhere else where it doesn't affect the measurement at 2400. They 
>think they that it is broke because the gain doesn't read what it says on the 
>cover.
>
>As far as NF goes and downconverter performance, the stub has very little 
>affect.  As long as you have no great losses from an excessively long feed 
>line, the gain actually needs to be reduced at the receiver. I use the 10 or 
>20 dB pad in my IC R-8500.  These downconverters are actually made for a 
>fairly long run of RG-59 cable.  That is why people are seeing S meter 
>readings of S-5 and above in their receiver with just the added converter 
>noise.

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