Topband: Received Signal Strengths

[Joel Harrison]

>From my perspective, "S" meter readings cannot give an accurate
representation of your station's RX performance, or at least it never has
for me, because evaluating or comparing signal levels would be very
difficult.

I use a calibrated panadapter where I get very good documentation of my
noise floor, in dBm, to begin with. Noise floor's will very from station
to station and given your QTH will vary from direction to direction if
your RX system is working properly. This also allows me to keep records of
my noise floor to identify any changes over time (if you don't, you
should!). If someone really likes to jack up a lot of "preamp gain" that
does nothing but cause related problems and you can definitely have a
signal "10 over" but your noise floor may be close to the same!!!

You don't need a preamp or a bunch of extra RX gain just because your
buddy told you so!! There are lots of good info out there to educate
yourself on whether you do or not (also a lot of BAD info!). Start with
W8JI's tutorial.

After evaluating my noise floor I then compare signal strengths to their
level above my noise floor, in dB, and never pay attention to my S meter.
This gives me accurate comparison to record day to day, or over time,
changes in my station, changes in propagation or several other factors.
That is vital in keeping my station working at an effective level, or to
compare when making improvements.

As far as "RST" goes, it would be awkward, but more meaningful for me to
send "S -120dB NF -128" for signal and noise floor levels rather than
"RST" but in reality for me whether I can actually copy the other stations
information (call sign, whatever report, etc) is what is important. If I
can copy it all clearly, regardless to signal level, it is a strength of
"9". I am very familiar with the history of the "RST" system but in
reality how applicable is it today with today's technology?

For my operating, it is just an exchange of information, for my station's
performance records, it is meaningless.

73 Joel W5ZN


www.w5zn.org