{Collins} Re: 75A4 Sensitivity Measurement



 
David,
 
Are you making an AM or SSB S/N measurement? If SSB, doesn't it call for a  1 
KHz carrier offset frequency, yielding a 1 KHz "signal" frequency for S+N/N?  
At any rate, that's what I would use. There would be no "modulating  
frequency."
 
And somewhere, I remember Collins specifies a 6dB pad between the source  and 
receiver.
 
Let us know what you find, please.
 
Jim Young W8MAQ
CCA Since 1994
 
 
 
In a message dated 6/5/2007 10:02:28 A.M. Eastern Daylight Time,  
dhallam@xxxxxxxxxxxx writes:
I am  attempting to measure the sensitivity of a 75A4.  The manual states  1
uV for a 6 db S/N (S+N/N?) ratio.  It does not state anything  about
modulating frequency.  I find that my uV readings at 400 Hz  are
approximately 1/2 of those at 1000 Hz.  Does anyone know which  frequency is
correct to use?  I am using a HP 606B signal generator  and a HP 400FL  AC
voltmeter.

David
KC2JD/4







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