[Heath] SB-303 Noise Blanker Schematic

[ChrisIwata at aol.com]

Hmm,
 
My last post about the noise blanker may be wrong. True the blanker is not  
the same as the SB104 blanker.
 
But, maybe this blanker operates as a side chain as opposed to the SB104  
blanker. This means the noise and threshold comments I made are not true. It  
depends where the output of the blanker is connected: If connected to a 
switch  (transistor or diode) that shorts the IF output then it operates as a 
side  chain.
 
In the SB104 blanker, the signal is passed thru a MC1350  IC which has 
about 50dB gain. Then the signal is attenuated to provide  unity gain. The 
blanking pulse is applied back to the IC control pin which  lowers the gain of 
the IC.  The IC is always in the signal path.  This  is not side chain.  
 
Chris KL7DM
 
 
In a message dated 3/15/2014 7:00:53 P.M. Pacific Daylight Time,  
pbrickey at verizon.net writes:

Hi,
I have had quite a few questions about this, so I  thought I would send out 
the schematic that is in my SB-303 manual.
It is  attached.
73's,
Peter


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