[Moon-net] QSO or not?

Wed May 2 03:21:29 CDT 2007

Gents,
After may hundreds of  JT65A QSOs on 6m ionoscatter, I have observed that 
there if there are any 'birdies' present on the frequency, it is not 
uncommon to see decodes of shorthand messages. I have one PC that makes 
lines that are almost invisible on the waterfall display, but that causes 
false shorthand decodes as often as 1 period in 4 with no other signal 
present.  The other side of the coin is that the presence of a real 
shorthand report may not decode, despite it being plainly audible.
The shorthand message decoding is very sensitive, and you may overlook 
birdies that are strong enough to cause a problem.

Perhaps there is room for improvement in the zap feature? I am not sure if 
the decode takes much heed of the last 10 seconds of the 1 min period, but 
It may be useful if the software were to examine this time period for 
apparent continuation of shorthand messages, and maybe flag with a ?
We live in an RF environment that is getting dirtier all the time.  Immunity 
to this sort of problem may be worth sacrificing a small amount of 
sensitivity for.
This is only one possible explanation for problems observed, but it is one 
that I am sure others have experienced. You can live with this sort of 
problem, but need to operate the software with a mind to its possible 
behaviour.

regards
Mark GM4ISM

----- Original Message ----- 
From: <jimmyv at hol.gr>
To: <moon at moonbounce.info>; <moon-net at list-serv.davidv.net>
Sent: Wednesday, May 02, 2007 9:19 AM
Subject: [Moon-net] QSO or not?

> Hello all
>
> I am trying to understand how JT65 works sometimes (even without Deep 
> Search!),
> especially when it comes to expeditions. I am confused.
> Could you please explain to me how is possible to have a QSO as complete 
> in the
> log of an expedition, when the station calling them says it is not 
> complete?
> However, expedition says it has data files for all QSOs. So does the 
> station
> trying to work them. So where is the error?
> This is even more profound because in the case of JT65 it is even more 
> difficult
> to make a personal judgement mistake. Since software algorithms do the 
> decision
> making for you and we have been told that reliability of a contact remains
> intact. Regardless of signal level.
>
> As i do not question the integrity and experience of operators in the 
> specific
> expedition (in fact they are experienced operators with good operating
> standards), neither do i question the experience and integrity of the
> particular station calling them, then is it the JT65 software generating 
> the
> error? I think, and hope, not.
>
> Perhaps is it the plain shorthand messages? To me, it looks like this 
> being the
> reason, because shorthand messages are not accompanied with callsigns 
> (unless
> the Big exception of someone transferring both reports and callsigns as 
> unknown
> text). Therefore, using the standard format of shorthand messages, in a 
> pileup
> situation, one can not be sure if the RO or Rs received was for him or
> not...(as logger extract shows below at 5:19)
> We have seen situations with other expeditions in the past.
>
> To substantiate my argument and subsequent confusion with facts, pls find 
> below
> extracts of ON4KST logger showing PE1BTX saying to ZB2/DH7FB he did not 
> have
> complete QSO with ZB2 expedition. At the end of this mail, pls see the log 
> of
> ZB2 expedition where QSO is listed as complete.
>
> Once more, i will repeat this is nothing personal and NOT aiming the 
> operators
> involved; the specific case is merely used as another example. But just
> scratching my head as to how some QSOs eventually take place and the 
> totally
> different outcomes reached. Your help in understanding what is happening 
> is
> appreciated!
>
> Thanks in advance & 73,
> Jimmy SV1BTR
>
> ON4KST logger:
> 05:26:40 PE1BTX Gerard 4X12/QRO Frank, but despite my NC congrats on your 
> FB
> operation, you gave a lot of stations a new DXCC
> 05:24:05 DH7FB frank gerard, yes in next time we will also do this
> 05:19:50 PE1BTX Gerard 4X12/QRO Frank, could be, pse look my EME log
> http://www.pe1btx.nl/EME%20initials%20all%20bands.htm
> 05:19:16 DH7FB frank gerard, so the received "ro" came fm another stn 
> maybe
> 05:16:17 PE1BTX Gerard 4X12/QRO Yep, NC for me, but already wkd ZB2IQ back 
> in
> 1983 on ES, and confirmed
> 05:13:57 PE1BTX Gerard 4X12/QRO Found my QSO complete in the log, but 
> never
> send RO to him on 21st, so not complete for me, did not even had a decent 
> decode
> on 21st, very strange
>
>
> PE1BTX Log (bottom of his webpage)
> http://www.pe1btx.nl/EME%20initials%20all%20bands.htm
>
> ZB2 log:
> http://www.df2zc.de/hamradioresults/seite5/022c0a991e127580c/index.html#022c0a992008a0a01
> EME
> 21.04.2007
> 1110-1113 PE1BTX O/RO -21 dB C 9
>
>
>
>
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