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Re: R: S units



Hi Guys,

Here is a copy of the standard:

http://www.y06.de/y06/tools/S_Meter.pdf

It shows S9 = -73 dbm0 (i.e ~50 microvolts) for
30 MHz and lower and S9 = -93 dBm0 (i.e. ~5 microvolts)
for over 30 MHz.

As I recall, it was James Millen of the National
Radio Company who made the original proposal
of a standard 50 uV = S9 and 6 dB per S-unit.

However, I can't think of a single manufacturer of
Ham radio gear that gets even close to following
this. I recently checked my FT-817 and it is less
than 1 dB between S0 and S2!

Cheers,
Tony AA2TX

---


At 03:45 PM 10/6/2003 +0200, i8cvs wrote:

>Hello Gerry K6TXD,
>
> From the "VHF MANAGERS' HANDBOOK " of IARU Region-1:
>
>Standardization of S-meter Readings
>
>At the IARU Region-1 Conference in Miskolk-Tapolka (1978)
>following recommendation was adopted:
>
>IARU Region-1 adopts as a provisional standard the value of 6 dB
>for the "S-point", and this value will be recommended to manufacturers
>of equipments.
>
>At the meeting of the IARU Region-1 VHF/UHF/SHF Committee in
>Dusseldorf (April 1989) the following recommendation was adopted,
>ad later approved by the IARU Region-1 Executive Committee:
>
>The S 9 reference level for frequency bands above 144 MHz is -93 dBm
>available signal power at the receiver input.
>                                            --------------------------------
>
>Please note that -93 dBm is the power applied to the receiver input and not
>the power indicated by your signal generator  with open output.
>
>73" de
>
>i8CVS Domenico
>
>
>----- Original Message -----
>From: Gerald Horn <ghorn666@earthlink.net>
>To: <amsat-bb@AMSAT.Org>
>Sent: Monday, October 06, 2003 5:55 AM
>Subject: [amsat-bb] S units
>
>
> > Hello
> >
> > Is there a definition of what an S unit is. I am building a home brew
> > receiver and I don't know what to calibrate the meter to.
> >
> > gerry k6txd
> > ----
> > Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> > Not an AMSAT member? Join now to support the amateur satellite program!
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> >
>
>
>
>
>
>----
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>
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