Re: Topband: One Way Propagation.

[Grant Saviers <grants2@pacbell.net>]

Then with FT8, the "db" rating depends on S/N not signal power.  I hear 
well so my report is most frequently better than received.  The big guns 
are an exception with well engineered stations in good locations. 
However, FT8 "db's" being S/N do wash out the gain loss when using Rx 
antennas.
Of course, my Flex computation of the power in an FT8 band segment is 
totally meaningless.
Grant KZ1W

On 1/17/2021 08:22, Michael Walker wrote:
> All Flex radios measure signal strength regardless of the PreAmp settings.
>
> As well, they correctly calculate the power in the receiving passband.
>
> Early superhet radios use maxim signal that was rectified into a DC voltage
> to provide an S meter reading and to also drive the AGC.  This is why when
> the AGC is off, there are no S meter readings.  (that is the simple way to
> describe it).   It is also likely that they are not well calibrated other
> than to show that S9 is -73dbm and plus or minus that is not what you think
> it should be.
>
> The 'S' value is also calculated based on the 50ohm input level at the
> receiver, not the antenna.  This will also result in different readings
> from different users since antenna systems are all different.
>
> In the end, the information is for reference only and is useful for comping
> changes at your own station.  Now, if SNR was actually reported then
> stations could start to compare similar readings.
>
> Mike va3mw
>
>
> On Sun, Jan 17, 2021 at 11:10 AM Wes <wes_n7ws@triconet.org> wrote:
>
> > I'm not going to smack this tar baby, other than to note that Elecraft is
> > a
> > special case with respect to S-meters.  K3(S) have an "Absolute" mode that
> > compensates for preamp gain or input attenuation. So the S-meter becomes a
> > decent power meter.
> >
> > I think it's unconscionable that other manufactures, with microprocessor
> > controlled radios, haven't incorporated this.  They should be fully
> > capable of
> > measuring their own preamp gain and attenuator loss and compensating the
> > meter
> > accordingly.  I throw into this criticism the TS-890 that I just
> > acquired.  My
> > goodness, they went to the effort to incorporate a decoder for PSK, of all
> > things, but can't provide a decently calibrated S-meter.
> >
> > Wes  N7WS
> >
> >
> > On 1/17/2021 7:26 AM, Don Kirk wrote:
> > >    Hi Roger,
> > >
> > > Signal report comparisons with the modern radios that often have preamps
> > > that you can switch in or out really clouds the picture as well as the
> > fact
> > > most stations on topband use RX antennas.  Assuming that all
> > manufacturers
> > > have S meters that are calibrated identical to each other (which is not
> > the
> > > case), the big question is if the S meter calibration was done with the
> > > preamp on or off, and if the person that is giving you a signal report
> > has
> > > the preamp on or off.  As an example the Elecraft S meter uses the common
> > > standard of S9 = 50 uV but the calibration is done with Preamp 1 on.  And
> > > when a station is using an RX antenna everything goes out the window
> > since
> > > RX antennas often have very negative gain, and then if an external preamp
> > > is being used that adds another variable.  And if just using a TX antenna
> > > for receive there is a lot of difference in each stations antenna
> > effective
> > > gain (due to ground losses, etc.) that adds another variable.
> > >
> > > A signal report of S2 or S6 tells me nothing on how well I am being heard
> > > since I need to know what your noise floor is too (unless you are telling
> > > me how many S units above your noise floor I am ????).  What helps me the
> > > most is to understand how many dB above your noise floor I am, and that
> > is
> > > why you will see that when I spot a station on DX Summit, I say how many
> > dB
> > > the station is peaking and that means how many dB above my noise floor
> > the
> > > station is peaking (I think this is similar to what you see for signal
> > > reports on the RBN).
> > >
> > > Just FYI,
> > > Don (wd8dsb)
> > >
> > > On Sun, Jan 17, 2021 at 8:04 AM Roger Kennedy <
> > roger@wessexproductions.co.uk>
> > > wrote:
> > >
> > > > Well personally I always give Signal Strength reports from my S Meter .
> > .
> > > > .
> > > >
> > > > So it doesn't matter whether my Noise Level is S2 or S6 . . . I'm
> > telling
> > > > you how strong your signal is at my QTH.
> > > >
> > > > Roger G3YRO
> > > >
> > > >
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