Q: What is this traffic/mode? #modes


Klaus Werner
 

On the bands from time to time I see messages like the one in the screen snip. Only ever one side of the exchange, if it is an exchange. The call signs are very similar to amateur radio calls but can’t find them on QRZ.com or general web search. What are they?

Thanks,

Klaus

G7RTI

 


Bill Somerville
 

On 21/05/2021 10:24, Klaus Werner via groups.io wrote:

On the bands from time to time I see messages like the one in the screen snip. Only ever one side of the exchange, if it is an exchange. The call signs are very similar to amateur radio calls but can’t find them on QRZ.com or general web search. What are they?

Thanks,

Klaus

G7RTI

Hi Klaus,

the decoders in WSJT-X are working close to the theoretical limits of sensitivity, that necessarily means that occasional false decodes occur. The nature of the compression used to get the utmost utilization of the limited number of payload message bits means that random false decodes will have similarities to valid messages. You must apply some common sense and realize that such decodes are not due to transmitted messages, often a gridsquare that doesn't match the geographical location of the message sender is an obvious clue, also message forms like the above contest message decoded when no contest activity is expected is another indication of a false decode.

As has been said before, if there are no false decodes then the decoders are not working at their optimum sensitivity.

73
Bill
G4WJS.


neil_zampella
 

Unless there was some sort of contest going on, with the dB of -21, I suspect false decode.

Neil, KN3ILZ

On 5/21/2021 4:24 AM, Klaus Werner via groups.io wrote:

On the bands from time to time I see messages like the one in the screen snip. Only ever one side of the exchange, if it is an exchange. The call signs are very similar to amateur radio calls but can’t find them on QRZ.com or general web search. What are they?

Thanks,

Klaus

G7RTI

 





Tom V. Segalstad
 

Hi Klaus,

 

This looks like a false decode.

When the signal strength is so low as -21 dB (or lower), you must be suspicious.

 

Here is a false decode I got today on 6 meters, even at -15 dB:

091115 -15  2.0 2064 ~  NJ4WMH HJ2JUR/R R GD98

 

And here is one false decode with -18 dB which I got yesterday night, apparently from New Zealand, but we had no propagation from Norway to New Zealand on 6 meters:

221345 -18  0.5 1210 ~  TU; 4V6CMZ ZL0POH 559 0056

 

73 from Tom, LA4LN

 

 

Fra: Klaus Werner via groups.io
Sendt: fredag 21. mai 2021 kl. 12.22
Til: main@WSJTX.groups.io
Emne: [WSJTX] Q: What is this traffic/mode? #modes

 

On the bands from time to time I see messages like the one in the screen snip. Only ever one side of the exchange, if it is an exchange. The call signs are very similar to amateur radio calls but can’t find them on QRZ.com or general web search. What are they?

Thanks,

Klaus

G7RTI

 

 


--
Tom (LA4LN)


Klaus Werner
 

Thanks for the clarifications – makes perfect sense.