[TowerTalk] Activity by Mode was: Re: Fwd: MFJ QRT on May 17, 2024

[Pete Smith N4ZR]

I suspect this thread should move to another reflector, but before it 
does ... I don't want a few misconceptions to pass uncorrected.

Steve says "note how many timers a CW caller is spotted on RBN while 
calling in a pileup."  The answer, to the best of our ability, is NONE. 
It does happen very occasionally when the timing between caller and the 
called station's CQ is just right, and the caller is within 50 Hz of the 
CQer, but that's it.  Split callers are never spotted by the RBN.

Steve also asks "where are the RBN spots [in the CWTs?"  The answer is, 
there are TONS.  I don't have a huge signal, yet I was spotted over 100 
times in the last 10 minutes in the 19Z CWT last week.  Yes, I was CQing.

Looking at my own RBN node, I routinely spot CW signals with 
signal-to-noise ratios of as little as 4 dB.  To be sure, FT8 is much 
better at signals below the threshold (I see -24 dB signals all the 
time), but 4 dB is pretty weak.  So yes, there will be 
disproportionately more FT8 spots, but the RBN spots many relatively 
weak signals.

I'm not arguing that the RBN is directly, precisely comparable to other 
tools for measuring activity, but it's what we have for CW.

73, Pete N4ZR

On 4/29/2024 10:32 AM, Steve Harrison wrote:
> On 4/28/2024 6:13 AM, John Webster NN1SS wrote:
>> I would like to suggest that there may be broader implications.  On any
>> given day, more than 80% of all activity on the HF bands is in the
>> digital modes and largely in FT8.
>>
>> Look at RBN spot data that was collected (I assume) last year:
>
> I would venture to suggest that attempting to use RBN data to adjudge
> intermittent and erratic CW callsigns as being an indicator of band
> activity is a fallacy of and by itself. For example, note how many times
> a CW caller is spotted on RBN while calling in a pileup. Or when in a
> QSO and only signing once, and maybe every other ten minutes or two. RBN
> requires several clear decryptions of an audible CW signal before it
> will register a callsign... and then only when the decryption is clearly
> a callsign, but it will also show something that somebody mangles while
> attempting to send their call (which happens, believe it or not).
>
> And what about the weekly CWT contests.... where are the RBN spots to
> show that activity?? They mostly don't appear, because callsigns aren't
> "heard" more than once or twice, or most of the time are always shifting
> frequency. Or when they do appear, the RBN more often only shows the
> strongest signals, rarely the weak pipsqueaks or those at the bottom of
> a propagation peak.
>
> That's not quite what happens with something like ft8 or 4, which
> transmissions contain almost nothing BUT callsigns, and for minutes at a
> time. Of course, ft8 is going to appear to be a more-heavily-used mode
> in comparision.
>
> And as Pete said, RBN doesn't register SSB signals (unless purposely
> spotted).
>
> Don't try using RBN as any indicator of relative activity for any mode;
> it can't and doesn't compute.
>
> Steve, K0XP
>
>
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