Oh, I don't think you are being a jerk at all, and I don't take offense!
This newsgroup is all about sharing, and I appreciate your contributions,
along with everybody elses contributions. This is what it is all about!
Anyway, I didn't see that original spec that the person gave, but looking
at the ad again, I do see what you mean. The whole point I was bringing up
was the statement that the seller made about the RA17 being able to hear
weak signals better than the 6790.............I believe that there was some
sensationalism in that statement. What I was also saying was that if two
receivers have a low enough noise floor such that antenna noise overrides
the internal noise of the system, both of the receivers should be able to
hear the same signal. One of the units may have better audio quality and be
more pleasant to listen to, but I think that this is about as far as things
go.
Now, it could really be that in Racal's specification that they are actually
specifying a sensitivity of so many uV for an 18dB S+N/N ratio. I just don't
know.
I do understand what you are saying about distortion analyzers...........I
have an HP 339A of my own, but most of the time I use it for characterizing
audio equipment or for aligning the detectors of FM systems using the SINAD
method.
I remember the 334A also had an envelope detector so that you could measure
the distortion of RF sources up to 50MHz. I also do realize that one of the
best ways to check a radio is to measure the distortion of the RF, detector,
and audio chain by injecting a modulated RF signal at the antenna input at
around 1000uV and measuring the distortion at the audio output with a
distortion analyzer. This is one of the tests I do with my own homebrew
receivers............I shoot for under 0.5% distortion; if this occurs, I am
relatively happy.
On a final note............................feel free to shout me down
anytime, either in this NG or directly. I realize that I only know a small
portion of what there is to know, but I try!
I wish you the best!
Pete
wrote in message
oups.com...
Note that the advert said "Signal / noise 18 db. " Now of course the
seller doesn't know where you live, so the argument about excess noise,
though interesting, doesn't seem relevant to the ad. I'm not trying to
be a jerk, so please don't take any offense.
Most distortion analysers measure signal to noise and distortion. I
beleive the AOR 7030 has a similar spec, which would make sense given
the Lowe and AORUK history.
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