[Moon] Decode at what level?

Fri Dec 18 02:35:54 CET 2015

Thanks for that link.  Actually found I had 
already saved the G3SEK note but useful to review 
when starting out on a new mode (and for eme newcomers).

I have one question about signal reports and it 
is why are Tone reports still used?  Everyone 
sends RST as **9.  T never is some other number 
but always 9.  I understand the historical use of 
it but with modern equipment there is almost no need to send tone reports.

So why not just RS = 59 or 35 or ?  Seems like 
unnecessary info which can only confuse and not 
add to coherence of communication.  SSB never 
sends the tone or audio quality number.

Of course "its always been that way" but really 
why is it continued for CW-eme.  Too hard to change?

73, Ed - KL7UW
I have some other question on current practise on 
CW-eme but will hold them for a future time.

At 09:21 AM 12/17/2015, Peter Sundberg wrote:
>Hi Matej, pse take a look at the Prague 
>recommendations at http://www.zen70432.zen.co.uk/Initials/index.html
>
>The G3SEK notes explain the report system pretty 
>well. That is the basic scale I am using when sending a report.
>
>However, it is all relative, and these days 
>really big signals are more of a norm on 70cm 
>and especially on 23cm than in 2002. The S-meter 
>on my TS-2000X is indeed showing S9 for the 
>really strong stations. Again, all relative of 
>course, I have not calibrated the S-meter.
>
>73
>Peter SM2CEW
>
>
>
>At 08:54 2015-12-17, you wrote:
>>Hi Peter, I don't want to attend to senseless 
>>talksÂ about the oftenÂ telegraphy vs JT65 
>>topic, but I would like to ask you about the 
>>EME reports. First there isÂ recommended RST 
>>scale defined in IARU REGON 1 1978 Document M/T 
>>63, where is noted how many dBm are equal to 
>>1S. This scale can be seen for an example at: 
>>http://www.ok2kkw.com/00003016/rst_1978.png 
>>(http://www.ok2kkw.com/00003016/rst_1978.png) 
>>As most of the readers know, due to this table 
>>is different definition of 1S on SW,HF and 
>>above 30 MHz (1S correspondent to -121dBm or 
>>0,21uVÂ  below 30MHz and -141dBm or 0,02uV 
>>above 30 MHz). It's important to remind it 
>>because the most of EME stations above 70cm are 
>>using transverters with HF radio on IF. As the 
>>result they can't use their Smeters to tell the 
>>true value ofÂ S (and I would continue with 
>>question about the ordinary Smeter 
>>calibration..). Next thing is gain of LNA, who 
>>is using attenuator to have calibrated 0S of 
>>the Smeter with the LNA's gain? Next think is 
>>setting of AGC and the fast changing of signal 
>>levels. What is marked in S/N log, peak or 
>>average? How long average?... So this was the 
>>IARU definition. But when I start with CW EME, 
>>I learned that there is different definition of 
>>RST for EME by ARRL Handbook ( 
>>http://www.qsl.net/kl6m/emeops.htm 
>>(http://www.qsl.net/kl6m/emeops.htm)Â ) Due to 
>>this scale is the maximal report on EME 569. 
>>When I was studying the old EME papers I 
>>learned that that was due to used ERP in 70's 
>>as at that time nobody was able to deliver S9 
>>(-93dBm) signal off the Moon to the receiver. 
>>Today when I'm reading K2UYH's NL (tnx for fb 
>>work AL btw), I'm often reading about 599 
>>reports on CW EME and I'm confused. Are 599 
>>reports on EME wrong or not? They cannot be 
>>right in ARRL EME scale. But (!).. And the 
>>definition by IARU about the RST scale was set 
>>for IARU Region 1 area and how about IARU R2 or 
>>R3?Â  :-) If I take RST scale for EME by the 
>>ARRL, how is different definition what is 4 - 
>>fairÂ  vsÂ 5 - good? As the result RST used in 
>>telegraphyÂ EME is very relative for me (it's 
>>relative in MGM of course too) and I ratherÂ 
>>use TMO.. Peter just one question, when you 
>>areÂ using RST on EME, which kind of RST scale 
>>are you using: ARRL scale for EME or IARU 
>>scale? (on EME I've been using ARRL definition 
>>yet). Or do you use only the RST definition as 
>>the comparison of your S/N measuring? 73 Matej, 
>>OK1TEH ---------- PÅ¯vodnÃ zprÃ¡va ---------- 
>>Od: Peter Sundberg <sm2cew at telia.com> Komu: 
>>moon at moonbounce.info Datum: 16. 12. 2015 
>>20:32:31 PÅ™edmÄ›t: [Moon] Decode at what 
>>level? "Long time ago moonbouncers were more 
>>concerned with noisefigure and antenna gain and 
>>G/T merits. Now it seems like the only merit an 
>>EME'er is interested in is the level at which 
>>WSJT Deep Search is decoding (ho-hum) a message 
>>with two calls and a locator. We constantly 
>>hear stories about quad processors, VAC, extra 
>>hot soundcards, super hot drivers etc. A 
>>comparison to CW is often made, just to point 
>>out how Deep Search excells in copying over a 
>>CW operator. Some days ago I read someone 
>>saying that the difference is 10-15dB. The guy 
>>who gave this statement was cheered on by a his 
>>good buddy in Canada with these kind words 
>>(dismissing the rest of the EME community): 
>>"Joe remember we are nothing without you!!!" 
>>Good to know. However, it is interesting to 
>>note what K1JT said some time ago: "The FEC 
>>code used by JT65 is a low-rate code (r = 
>>12/63) and consequently it, too, benefits 
>>greatly from an ability to "copy on the QSB 
>>peaks"." Remember that Deep Search requirement 
>>to make a guess in relation to the database is 
>>just fragments of the full message, not 
>>unlikely to be presented at a short libration 
>>QSB peak. We are not talking about a full 
>>decode. And Rex VK7MO says: "While the majority 
>>of stations are stable to within a few Hz quite 
>>a few drift 20 Hz or more. While the AFC on 
>>WSJT can follow this on a strong signal - those 
>>who drift should be aware that they are giving 
>>up the last few dB of performance(signal 
>>reports are misleading in measuring performance 
>>as a drifting signal may decode at -30 dB when 
>>its real level is -20 dB)." In another forum 
>>G4SWX states the following: "Having watched the 
>>CW vs JT received signal strength discussions 
>>for many years and at the risk of fuelling 
>>another heated debate I have been dismayed that 
>>the same issue of simulation vs real world EME 
>>also exists. With CW signals reflected off the 
>>moon a good operator will recognise characters 
>>and part characters on Libration peaks although 
>>the average signal level can be below their 
>>audible threshold. This clearly can result in a 
>>greater 'sensitivity' for reading EME CW 
>>signals over that of simple simulations. So my 
>>million dollar question is - of what importance 
>>are these computer generated magic S/N numbers, 
>>when we can clearly see that they are all over 
>>the place due to real world factors? Are they 
>>of marketing or EGO purposes only? Or are they 
>>a TRUE figure of merit for a moonbounce 
>>station? If not, why are we seeing these 
>>endless reports of S/N decode levels on the 
>>cluster, loggers and forums? If they are true 
>>figure of merit, why not start making Deep 
>>Search decode (ho-hum) S/N measurements at EME 
>>meetings instead of NF measurements. Because 
>>this seems to be the thing that people are most 
>>interested in these days. For me it's TMO or 
>>RST - because CW is King! 73 Peter SM2CEW 
>>_______________________________________________ 
>>Moon mailing list Moon at moonbounce.info 
>>http://lists.moonbounce.info/listinfo/moon" 
>>_______________________________________________ 
>>Moon mailing list Moon at moonbounce.info 
>>http://lists.moonbounce.info/listinfo/moon
>
>
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73, Ed - KL7UW
http://www.kl7uw.com
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