> Depending upon the symmetry of the IF and detector component
responses,
> there will be a difference in the apparent sensitivity with
different
> deviation levels. The operative word is "apparent." If you intend
to use
> the receiver for FM voice which averages about 3 kHz deviation,
then
--- In Repeater-Builder@yahoogroups.com, "Bob M." <[EMAIL PROTECTED]> wrote:
>
> I thought that's the whole idea behind the SINAD
> measurement method, and why it's "so much better" than
> the 20dB quieting method.
It may well be, but for those of us without sinadders, then what?
Yahoo!
Another item to throw into the topic is the crystal osc
alignment also changes your sensitivity. Freq-center
may not give the best sensitivity depending a number
of other parameters. One might hope it does, but it's not
always the case.
skipp
> "Dave VanHorn" <[EMAIL PROTECTED]> wrote:
>
>
Ok, I wasn't thinking in this direction before, but I do have an audio
band spectrum analyzer handy.
Question is, how can I translate this to a Sinad measurement?
Looking at the receiver in question now, the second harmonic of the
1kHz tone is -40dB, and the noise is at about 5dB below that.
--- In Repeater-Builder@yahoogroups.com, "Bob M." <[EMAIL PROTECTED]>
wrote:
>
> I recall reading somewhere that the SINAD measurement
> is the residual signal after the 1kHz tone has been
> filtered out.
Right
> When that level gets to 12dB
> below the no-signal noise level, you've reached the
Well, I should be able to answer those questions soon, as my Sinadder
just arrived. No time to play tonight, but ASAP.
I did a quick check, plugging it into the tone out on my HP generator
where it shows >20dB with the 1kHz tone on, and 0 with the 400Hz tone
on, pretty much as expected.
But
So I snuck in a minute to play with the new toy.
If my meter is reading right, I'm at 0.24uV for 12dB sinad.
I tuned by ear, and got 0.26, so not THAT bad, but with the meter I
don't have to listen to the tone and noise that drives me nuts.
This is a Hae Dong meter, there are more on Ebay for $
Just search on sinadder
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I'm willing to guess that if you built one, someone here on this list
could help you calibrate it against their service monitor.
Chuck
WB2EDV
>
>I wouldn't mind building a sinadder, but I don't know how I'd
>calibrate it.
>
>
>
>
Yahoo! Groups Links
<*> To visit your group on the we
Hello to the list. A very good and super inexpensive Sinad meter can be
an old Heathkit audio distortion meter. Any distortion meter will work,
but the old Heathkit units are around and are super cheap. Simply
connect across the loudspeaker and with a strong signal into the radio
to be teste
I recall reading somewhere that the SINAD measurement
is the residual signal after the 1kHz tone has been
filtered out. Assuming you have a full-quieting input
signal with 3kHz deviation and you've notched that
out, there snould be nothing left to measure. As the
signal gets noisier, the harmonics
At 3/6/2006 09:38 AM, you wrote:
>Ok, I wasn't thinking in this direction before, but I do have an audio
>band spectrum analyzer handy.
>
>Question is, how can I translate this to a Sinad measurement?
I've been trying to figure this out too, as I've been working on an audio
spectrum analyzer pro
Wouldn't the SINAD be the distance between the 1kHz tone "Spike" and
the noise "Grass"?
On 3/6/06, Bob Dengler <[EMAIL PROTECTED]> wrote:
> At 3/6/2006 09:38 AM, you wrote:
>
> >Ok, I wasn't thinking in this direction before, but I do have an audio
> >band spectrum analyzer handy.
> >
> >Question
I'd think it might, but the AC voltmeter is measuring
the average (or RMS-calibrated) signal that remains
after the 1kHz tone has been removed. I suppose it
only has to be attenuated by at least 12dB (probably
more) so it doesn't contribute to the rest of the
signal. But if the 1kHz tone level is m
At 3/6/2006 01:52 PM, you wrote:
>Wouldn't the SINAD be the distance between the 1kHz tone "Spike" and
>the noise "Grass"?
I assume you mean distance in amplitude.
Not quite. I think the noise would have to be summed over all frequencies,
including any harmonics of the 1 kHz that get generated
I checked the manual for my HP 334A Distortion
analyzer. The notch filter in that unit seems to be
capable of 80dB, and the bandwidth is quite narrow,
under 0.01%. This unit just removes the fundamental
and measures whatever is left.
I found several good articles and explanations of
SINAD measurem
Got an item number.. Hae Dong turned up nothing..
mike
-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] Behalf Of Dave VanHorn
Sent: Thursday, March 09, 2006 9:12 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Receiver Tuning
t: Thursday, March 09, 2006 9:12 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Re: Receiver Tuning
>
>
>
> So I snuck in a minute to play with the new toy.
>
> If my meter is reading right, I'm at 0.24uV for 12dB sinad.
> I tuned by ear,
I used the Sinadder when it first came out ... once my ear had
learned what to listen for, I quit using the it.
Neil
Original Message
From: [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Re: Receiver Tuning
Date: Fri, 10 Mar 2006 02
PROTECTED] Behalf Of
[EMAIL PROTECTED]
Sent: Thursday, March 09, 2006 11:43 PM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Re: Receiver Tuning
I used the Sinadder when it first came out ... once my ear had
learned what to listen for, I quit using the it.
Neil
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