Tom wrote:
None of this matters anyway, because the entire system is certainly not a
precision system. Why do we care what S9 is anyway? Every antenna is
different, so it tells us very little about how loud the guy is anyway.
S meters are useful for relative comparisons if verified for a dB change so
you can give comparisons between two signal levels. Other than that, they
are pretty much sources of meaningless information.
Mike wrote:
By the way, I have been talking in dBc/Hz. Are you? -80 to -90dBc
in a 300 Hz bandwidth is actually fairly good (e.g. equivalent to
-105 to -115 dBc/Hz composite noise spectral density). On the
other hand -80 to -90dBc/Hz is equivalent to -55dBc to -65dBc
when listening on a receiver with a noise bandwidth of 300 Hz.
That would translate into audible noise sidebands from adjacent
signals that were only S9+10db - yuck!
<snip> I still recall the days when a very prominent east coast
160 meter DXer would monopolize 1824 to 1826 in the 160 contests
with endless CQ's from his 2 KC wide phase noise machine. I
wouldn't want to go back to that.
to which Jim added:
Which sounds a lot like a 930 and an sb220 5 miles away in VT.
S7 phase noise over the entire dx window. Or the 1987 argument
between two FRC'ers and top band ops about whose
rig was causing the problems with noise and clicks...
and they were 20 miles apart, in the 930/940 days.
My point was:
S meters are relative. But they don't have to be. They CAN be
calibrated, and they CAN read in dBm. They can be a tool for antenna
AND relative signal evaluation. If we don't make inputs to our favorite
manufacturer along those lines...how will they EVER know what to do with
their next radio? Right now, a lot of it is iterative guessing.
Interesting thread on AGC/MGC MP vs. Orion, btw....I have to take a hard
look at my PRO in that regard.
N2EA
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