Re: LF: JT9-1 and 2, echoes, waterfall

[John Langridge <jlangridge@sbcglobal.net>]

The bursts you were seeing were resolved by several of us here stateside by selecting a different audio codec under setup/options.  I know of two of us that personally found the Direct-X HD codec listed in the drop down box to work well for Vista and Win7 64.

73,

John KB5NJD/WG2XIQ

---

From: Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>
To: rsgb_lf_group@blacksheep.org
Sent: Tue, October 30, 2012 8:33:26 AM
Subject: Re: LF: JT9-1 and 2, echoes, waterfall

Hi Eddie, LF,

Am 30.10.2012 11:25, schrieb g3zjo:

Hi Stefan

I found the lack / loss of decodes annoying, one cause was slight frequency drift in my transverter, WSPR is not effected but JT9-2 is.
I feel there were other periods of unexplained non de-codes too.

Was it you who mentioned the burst at the end of the signal. I was hearing a tuneful diddle at the end of G3XIZ transmission, I hear a burst of distorted rattle on my own signal.

Eddie

No, it was DF6NM who mentioned the burst at the end but i saw it as well. It was part of the end of my signal.

With the new version things became a bit better. The initial crashes didn't happen any more for me. As i assume, this is probably due to the decoder that has to much work to do in a 1 minute period when the range is set to center+-50 Hz and if the CPU power is relatively low or other task have to be performed to the same time. When reducing the range to e.g. +-10 Hz there was no problem on my XP PC (512 MB RAM)  (no decodes though). On my Win7 PC (32 bit, 4GB RAM) there were no problems and i got successful decodes.

Probably there have to be some improvements on the decoder. We all confirmed that these problems are not present in WSPR, so Joe may already know what the culprit is.

It's one of the first releases of the software so we obviously have to be patient for some more time.

On request of DU1GM i will transmit JT9-30, beginning arround 15 UTC on 137.44 kHz (+- a few Hz), full power!

73, Stefan/DK7FC