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RE: LF: JT9-10 @ 474 +1400

To: "[email protected]" <[email protected]>
Subject: RE: LF: JT9-10 @ 474 +1400
From: Rik Strobbe <[email protected]>
Date: Tue, 18 Dec 2012 13:57:46 +0000
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Thread-topic: LF: JT9-10 @ 474 +1400
Hello Tobias,

sorry, I didn't think of the lower offset (1000Hz) with JT9-10.
But I will stick to 501.4kHz TX frequency = 500.4kHz dial for 1000Hz audio.
I will start at 20:00UTC and initially go for 3 rounds (so 20:00-20:10 , 
20:20-20:30 and 20:40-20:50).
It will be just for test purposes:
1. check if my setup is stable enough for JT9-10.
2. if there is significant TX (or RX) drift to provide some audio files for Joe 
(K1JT)
So those who will monitor my signal are encouraged to save audio files of the 
transmissions and eventually send them to Joe.

73, Rik  ON7YD - OR7T

________________________________________
Van: Tobias DG3LV [[email protected]]
Verzonden: dinsdag 18 december 2012 12:41
To: Rik Strobbe
Onderwerp: Re: LF: JT9-10 @ 474 +1400

Hi Rik !

My station will be running. Please specify "tonight" more precisely. I
will try to sync on your signal and transmit/reply on the 475 kHz band.
Conditions seem to be very good these days as i was heard by OH5YW and
EI0CF during daylight already (on WSPR) !

Please consider using a lower offset than 1400 Hertz on JT9-10, as Joe
has written :

 From Joe K1JT "WSJT-X_Users_Guide.pdf" :

"3. The waterfall frequency range always starts at 1000 Hz. This means
that your on-the-air frequency range starts exactly 1 kHz above your
dial frequency. The upper frequency limit depends on JT9 sub-mode, the
setting of FFT bins/pixel, and the width of the waterfall graph. In
normal use the recommended audio frequency range is 1000–2000 Hz for
sub-modes JT9-1 and JT9-2, 1000–1300 Hz for JT9-5, 1000–1150 Hz for
JT9-10, and 1000–1050 Hz for JT9-30."

I do not have much experience with with JT9-10 yet, so I cannot tell
whether the above text is a recommendation or a must.

The "wide graph" window is automatically zoomed when using JT9-10, so
the absolute maximum Offset would be 1240 Hertz at 1 FFT bins/pixel.

See you tonite !

73 de dg3lv Tobias


Am 18.12.2012 09:10, schrieb Rik Strobbe:
> Hello Joe, all,
>
> if there are some "takers" I could do some JT9-10 transmission tonight on 
> 501.4kHz (500kHz dial) starting 20 UTC.
>
> The setup here is a Kenwood TS440 transmitting on 3.5MHz mixed with 3MHz xtal 
> osc. down to 500kHz, filtered and amplified to 6W RF (estimated 20mW ERP).
> With this setup I was copied up to 1600km (OH) in JT9-1 and JT9-2.
>
> It would be interesting to know if the frequency stability such a basic setup 
> is OK for JT9-10.
>
> 73, Rik  ON7YD - OR7T
>
> ________________________________________
> Van: [email protected] [[email protected]] 
> namens Joe Taylor [[email protected]]
> Verzonden: maandag 17 december 2012 23:47
> To: [email protected]
> Onderwerp: Re: LF: JT9-10 @ 474 +1400
>
> Hi Laurence, Steinar, and all,
>
> On 12/17/2012 5:15 PM, Laurence KL1 X wrote:
>> Steinar I was getting some reasonable syncs but appeared not
>> stable enough - so that confirms it :-) Laurence KL 1 X
>
> LA5VNA wrote:
>>> Thanks Tobias. The conclusion is clear , my system in NOT stable enough
>>> when using JT9-10. Pity , but that's life ;(
>
> Please send me an example of a JT9-10 file that seems like it should
> have decoded, but did not.  NOBODY has yet done so.  I am reasonably
> sure that small amounts of frequency drift can be detected and
> adequately compensated in software... but I can't do it without some
> typical examples.
>
> If you know it, it will help to have, along with the file, the message
> that was being transmitted.
>
> Note to all: I am presently working on a version or WSPR that will allow
> transmissions of length 10 (or 15?) and 30 minutes, with other features
> like the traditional WSPR.  Sensitivity should be as good as the WSPR-8
> and WSPR-32 tests made by Marcus (and others).
>
>          -- 73, Joe, K!JT
>

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