Beaconspot S/N reporting


Andy G4JNT
 

I've just placed a Beacospot for GB3MHZ (1296MHz), and I note that the entry form now allows a S/N report, as well as RST and  JT.   

Quotting S/N alone is meaningless - what bandwidth are people supposed to report it in? 1Hz, 300HzH, 2500Hz ?   
The text shown implies a negative sign means JT type reports relative to 2.5lkHz, but my report was +3dB (2500Hz) which is going to be ambiguous. A spot below mine, that from PA0JME, is listed as +25dB - which is almost certainly not in 2500Hz!   What bandwidth has he used?

What is intended by the S/N ?


Iain Young
 

I can't comment on what is intended, but I always try and add my
bandwidth (which is usually 250k as I'm doing SDR) to the comments
field

Iain.

On 02/10/2022 12:58, Andy G4JNT wrote:
I've just placed a Beacospot for GB3MHZ (1296MHz), and I note that the entry form now allows a S/N report, as well as RST and  JT.
Quotting S/N alone is meaningless - what bandwidth are people supposed to report it in? 1Hz, 300HzH, 2500Hz ?
The text shown implies a negative sign means JT type reports relative to 2.5lkHz, but my report was +3dB (2500Hz) which is going to be ambiguous. A spot below mine, that from PA0JME, is listed as +25dB - which is almost certainly not in 2500Hz!   What bandwidth has he used?
What is _*intended*_ by the S/N ?
Andy
www.g4jnt.com <http://www.g4jnt.com>


Andy G4JNT
 

NO not that bandwidth.  
To specify the S/N you need to specify the noise bandwidth.  If that's read from an FFT screen then it is usually equal to a couple or up to 3  FFT bins.   So if you have a sampling rate of, perhaps 300kHz (for your 250k screen width) and an FFT of 65536 points then your noise bandwidth is ~ 5Hz.  The exact number of bins depends on teh FFT window type in use




On Sun, 2 Oct 2022 at 16:36, Iain Young <g7iii@...> wrote:
I can't comment on what is intended, but I always try and add my
bandwidth (which is usually 250k as I'm doing SDR) to the comments
field

Iain.

On 02/10/2022 12:58, Andy G4JNT wrote:
> I've just placed a Beacospot for GB3MHZ (1296MHz), and I note that
> the entry form now allows a S/N report, as well as RST and  JT.
>
> Quotting S/N alone is meaningless - what bandwidth are people supposed
> to report it in? 1Hz, 300HzH, 2500Hz ?
> The text shown implies a negative sign means JT type reports relative to
> 2.5lkHz, but my report was +3dB (2500Hz) which is going to be ambiguous.
> A spot below mine, that from PA0JME, is listed as +25dB - which is
> almost certainly not in 2500Hz!   What bandwidth has he used?
>
> What is _*intended*_ by the S/N ?
>
> Andy
> www.g4jnt.com <http://www.g4jnt.com>
>
>






alwyn.seeds1
 

Dear Andy,

I thought the standard for beacon reporting was an equivalent noise bandwidth of 2.5 kHz?

On beaconspot it says "S/N report is in 2.5kHz bandwidth”.

So, I report accordingly.

As you say, SDR displays often do not make the bandwidth clear.

I even see spectrum analysers where you have to dig through menus to find the resolution bandwidth.

Regards,

Alwyn G8DOH


_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Andy G4JNT
 


Oops
I didn't spot the line just below that states just that :-( :-( :-(
I just saw :
"RST(e.g. 599) OR S/N in dB(e.g. +30) OR JT65 (e.g. -13) :" and didn't read any further


image.png



On Mon, 3 Oct 2022 at 10:05, alwyn.seeds1 <a.seeds@...> wrote:
Dear Andy,

I thought the standard for beacon reporting was an equivalent noise bandwidth of 2.5 kHz?

On beaconspot it says "S/N report is in 2.5kHz bandwidth”.

So, I report accordingly.

As you say, SDR displays often do not make the bandwidth clear.

I even see spectrum analysers where you have to dig through menus to find the resolution bandwidth.

Regards,

Alwyn G8DOH


_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________