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[AMPS] 2 tone intermod test

To: <amps@contesting.com>
Subject: [AMPS] 2 tone intermod test
From: measures@vcnet.com (measures)
Date: Tue, 23 Nov 1999 11:38:31 -0700
>
>Hello, I want to run a 2 tone intermodulation distortion test on my hf
>transceiver to check for splatter vs. compression level, microphone gain
>settings etc. I know this is not an amplifier question, but this list is
>probably where I can get the best answer. I'm running an Icom-756 (and Alpha
>89A). Running this test on an amp would be pretty straight forward, but how
>about on a transceiver? Does anyone know how the test is done on
>transceivers?
>
The 2-tone test does not simulate genuine rotten splatter.  For this you 
need a complex waveshape.  A human or an African gray parrot is such a 
source.  The splatter test is done by tuning a double-filter Rx (such as 
a TS-830) about 3.7KHz above and below the test signal to isolate imd 
products from the fundamental) and then comparing the signal strength to 
the fundamental.  Since S-meters tend to be inaccurate, a 1db step 
attenuator.should be used to measure relative signal strength.  
>
cheers, Dave

- BTW --   the only splatter that matters to the FCC is what goes beyond 
the Amateur Radio Service band.  
..

-  Rich..., 805.386.3734, www.vcnet.com/measures.  


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