Sinad is done with a 1000 Hz tone at 3KHz deviation and requires a meter that
can notch out the 1K tone and measure the remaining noise.
20dBQ is done with no modulation 2 Vac of sq noise w/ no carrier then generate
unmodulated carrier till the ACVM indicates 0.2 Vac
A major difference in the two usually meant an alignment issue or some sort of
problem in the back end of the receiver. Is the meter 4 circuit showing that
the channel element is on frequency, and have you checked the alignment of the
IF?
Proponets of the Sinad method claimed that their way of doing the alignment
would actually improve the overall sensitivity since the radio was being tested
while receiving audio.
Milt
N3LTQ
----- Original Message -----
From: Tim Sawyer
To: Repeater-Builder@yahoogroups.com
Sent: Monday, September 06, 2010 3:48 PM
Subject: Re: [Repeater-Builder] Micor UHF Sensivity
I'm getting about 0.35 for 12 db SINAD. But that looks about 10 db quieting
to me. What I typically do is open the squelch with no signal and set the
volume to 2 Vac then crank up the signal to 0.2 vac. Isn't that 20 db, or am I
missing something?
--
Tim
:wq
On Sep 6, 2010, at 10:46 AM, Eric Lemmon wrote:
spec is 0.5
uV without a preamp and 0.25 uV with a preamp, when using the 20 dB quieting
method, and 0.35 and 0.175 respectively when using the 1 2 dB SINAD method
