JT65. An Internet VHF/UHF QSO Machine???

WSJT 65 (and variants) Discussion
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JT65. An Internet VHF/UHF QSO Machine???

Post by VK3OT » Thu Jan 26, 2006 11:50 am

Reproduced from SM7AEDS pages..........

JT65. An Internet VHF/UHF QSO Machine???
If you are using JT65 you may be interested of reading the lines from a skilled EME operator.

Please open


Peter starts saying:

"I really dislike the present dumbing down of amateur radio. The JT65
software is helping just that, people have little understanding of what is going on, and standards are thrown out the window.
This is done without an open discussion among the EME group. One man, K1JT has decided to set his own standards, and thereby invented a QSO machine that heavily rely on known information and constant liason via the Internet.........."

Oliver, DL1EJA, January 07 2006:
"....the fact that the JT65A software has some very bad weaknesses and that some of the more experianced users don't like to have them published or removed. If this is really the case, then you might have the idea that it is wanted! The conclusion if this result is that this experience OPs like to run
"complete QSOs" with beginners who don't know anything about the "wrong decodings" and QSL........."



Post by VK2KRR » Thu Jan 26, 2006 1:36 pm

Interesting link Steve. Thanks for pointing that one out.

A few comments from me:

I personally think that WSJT is a brilliant achievement and has greatly helped advance Amateur Radio. Well done Joe Taylor K1JT.

JT65 is terrific for weak signal detection. I think its fairly simple and is a legal QSO. Virtually the same info can be sent on CW just in a different format.

"EME QSO's are no longer treated as achievements" - I think EME QSOs are over rated in the first place. I mean, its a bit like a satellite. We know when its going to be there, its going to come over the horizon at a certain time and set at a certain time. Its line of sight to a reflector from both stations. You just need enough antenna and power at each end.
Try working a 3000 Km terrestrial path each time the moon comes up and see how hard that is. Now thats an achievement.

"Well, it is mainly because of the JT65 software with false decodes, lack of
information being transferred over the airwaves and the need for full Internet liason to make the QSOs."
- Yes JT65 has false decodes if you leave the Call3.txt file intact. Thats why I deleted every callsign from within it to make it more realistic. You do not need full or any internet liason to make contacts.

there is not much decoding to be done when you just have to verify
the very presence of two tones.
- Yes but which two tones? different tone sets indicate a different message. CW is only a single tone sent with different lengths, even simpler.

How can correct callsigns be displayed without any input what so ever
(or just white noise) to the computer soundcard?
- By leaving the call3.txt intact. Delete the contents.

If you delete the file call3.txt from the folder, WSJT crashes! - Just delete the contents of call3.txt. Dont delete the whole file.

Now, this is where corners are really cut!! The program detects the tone separation, or establishes that one tone switches on/off at a rate of about 1.5 seconds, then it prints the shorthand message!! - Yeah? it has to work it out some how. Again CW has different length tones separated by certain time periods. Same thing.

So, instead of the CPU actually decoding R and O, one can look at the tone separation on a waterfall
display and say "Complete QSO!!". Is this a secure communication protocol? There is NO information
sent, there is only a pattern to be seen. In the quest for generating an EME QSO machine, this is about
a low you can go.
- Wtf? Actually the QSO is not complete when you see RO, you need RRR. But this is not the point. Does it really matter if the CPU decodes the R and O or if its seen on the waterfall? What difference is there to that and having your ears and brain decode a CW ... (ie dit dit dit) and a --- (ie dah dah dah). The ... or --- also generates a pattern on a waterfall display as you can see here ... --- so there is no difference. Yes there is information being sent R and O. exactly the same as the CW is also R O just sent a different way.

It is clear that Joe has done away with unknowns to produce his QSO machine!! - What? how do you know what the other station is sending and when? How do you know who the other station is?

QSO's are 99% set up via a logger or via the DX-cluster,
so the focus on radio communication has diminished to virtually non existing.
- I do know of a few early QSO's way before the internet that were set up by sending postal letters or by telephone. Again no different. Communication has not diminished, in fact it has increased due to a new level of efficiency and simplicity.


Post by VK3OT » Tue Jan 31, 2006 8:07 pm

This is why I posted it in the PC section and not the radio forums. 73

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