[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: AMSAT-BB Digest, Vol 3, Issue 619 SINAD Testing



Hello The Net:

SINAD is nice because the complete path from RF thru IF thru audio 
demodulation can be tested.
Also a cost effective approach, Last SINAD meter I got was about 100$.
It is a HELPER Instruments,Inc. model SINADDER LINEAR 5
SINAD measurements require an external signal generator, and variable 
attenuator.

A noise figure meter can usually test the RF path or the RF thru IF 
path, but NOT to audio.
For my HP-8970B, the IF would have to be more than 10 MHz, the low freq 
end of the machine.
NF meters are about 10-20X $$$ the SINAD meter purchase.

I use my NF meter in a Y factor mode, which is essentially a signal to 
noise ratio.
SINAD is also a Signal to Noise ratio, with Distortion taken into 
consideration.
(S+N+D)/(N+D). When noise is very low, and distortion is also low, thus 
a S/N.

SINAD was used by Motorola and FM radio testing with a 1000Hz test 
modulation.
Testing can also be used for testing SSB receivers, using a clean 
carrier with no modulation
and tuning the RX for max signal, max S/N, max SINAD reading.

Both instruments have their utility.

Stan, W1LE  Cape Cod,   FN41sr
>    2.   Re: MMIC for LEO preamp? (RFI-EMI-GUY)
>
>   
_______________________________________________
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb



AMSAT Top AMSAT Home