Hi Bob -

Thanks for your input!

I can understand the basic idea of a VHF/UHF offset for the "S-scale,"
based on the much lower ambient noise levels in that frequency range.
Twenty dB seems like a pretty large offset, though--but who am I to tell
the VK-VHF crowd how to do their "S-scale?" ;-)

Roger on your themal noise estimate. It's been a few years, but I recall
using -114 dBm/MHz as the thermal noise level back in my radar design
days. That would track with your figure. But S1 for you is 0 dB SNR
with a 0 dB NF? Wow, you VKs must have good ears!

73, Ed, W6LOL

"Bob Bob" wrote in message
...
So I cant resist

We had a similar discussion on the VK-VHF NG (a closed NG). The general
consensus for VHF/UHF SSB use as summarized by Gordon VK2ZAB was;
--------------
The scale is:
S9 = -93 dbm = 5 uV into 50 ohms.
S8 = -99 dbm = 2.5 uV
S7 = -105 dbm = 1.25 uV
S6 = -111 dbm = 0.625 uV
S5 = -117 dbm = 0.313 uV
S4 = -123 dbm = 0.156 uV
S3 = -129 dbm = 0.078 uV
S2 = -135 dbm = 0.039 uV
S1 = -141 dbm = 0.02 uV - Note that this fortuitously corresponds to the
level, on Earth, of the power due to thermal noise in a bandwidth of
2000 Hz.
And if you like:
S0 = -147 dbm = 0.01 uV
S-1 = -153 dbm = 0.005 uv
S-2 = -159 dbm
S-3 = -165 dbm
S-4 = -171 dbm
S-4.5 = - 174 dbm Note that this fortuitously corresponds to the level,
on Earth, of the noise power due to thermal noise in a bandwidth of 1Hz.
Those that wish to do so may exercise their arithmetic skills by
determining what S point and /or dbm level corresponds to the noise
power at say one [1] degree above absolute zero - which may exist
somewhere in space.
-------------

Note that there was a lot more discussion about the use/misuse of S
meter reports. I thought the scale the more useful though.

Cheers Bob VK2YQA



Old Ed wrote:
Hello All -

This reads like a tongue-in-cheek bit of good-natured trolling... but I
have
added a few comments, just in case some newbie takes it all too
seriously.

"Reg Edwards" wrote in message
...

..... etc