Set the new freq just after you announced the QSY, and get the
occasional demod at DF = +430Hz which is correct for 1700Hz sync. But
S/N has fallen and is now in the region of -30dB S/N so oughtn't
really to expect a decode.
Assuming JT65A is 3dB better than the B version, a S/N of around
-25dB ought to be the threshold based on past experience.
I'd know better if you could generate 3dB more signal :-)
Andy G4JNT
On 22/03/2008, Graham <[email protected]> wrote:
> Ok Andy,
>
> Well its decoding off air ok at my qth , keying looks ok offair and at
> birmingham ,
> im running 10 watts per tone (20 watts peak during dual tx)
>
> I have just made a qsy inside the passband , to set the jt65 above the wspr
> signal ,
> jt65 now using sync tone 1700 Hz dial freq still 501.5 usb
>
> Im not sure if wspr and wsjt6 will run at the same time , but I can try over
> the wekend
> if needs be , ive just downloded the windows version of wspr .. but not
> sorted out the
> soundcard yet as he's using , 0123 ... very trad hihi
>
>
> Tnx - G ..
>
>
>
>
>
> ----- Original Message -----
> From: "Andy Talbot" <[email protected]>
> To: <[email protected]>
> Sent: Saturday, March 22, 2008 8:28 PM
> Subject: Re: LF: Re: Re: WSPR == ON AIR TEST NOW 1545 HRS = 503 KHz
>
>
> > Very Interesting. In the WSJT user screen there are several sucessive
> > -19dB S/N individual listings and, out of 70 sequences, it has
> > selected 22 of them as being valid, but not one single correct decode.
> > Experience on JT65B receiving the GB3RAL and GB3VHF beacons shows
> > that -19dB S/N will give perfect copy, and -22dB will decode after two
> > or three averaging sessions, so there's something very odd going on.
> > What I can make out on the spectrogram, the sync tone is in
> > more-or-less the righ place.
> >
> > Your WSPR signal is just 3 Hz low, and the JT65A sync tone about 15Hz
> > lower that stated, which is more than near enough for a valid decode -
> > and the user screen shows its doing just as it should - with some
> > strong enough individual demods BUT NO DECODES - why???????????????.
> >
> > Do I understand you are not using the actual WSJT software to encode
> > the data? Are you actually sure the MultiPSK implementation is doing
> > its job properly.
> > Try WSJT 5.98
> >
> > Andy G4JNT
> >
> >
> > On 22/03/2008, Graham <[email protected]> wrote:
> >> Ok Andy,
> >>
> >> Looks like making headway ....
> >>
> >> I'm using multipsk (the test version) which has jt65-modes .. and for
> >> want
> >> of a better way of describing the frequency ..sorry if it sounds a 'cb'
> >> like ... but .. ' The purple line' is set at the 1000 Hz mark on the
> >> waterfall display giving 1002 hz showing on the l/h fequency window
> >> ...as
> >> you say is 270 hz (ish) from the normal point ... but if you set the
> >> prog
> >> to that point , means you can engauge the narrow filter
> >>
> >> WSPR is running at 1500 Hz tone o/p giving 503.00 khz rf carrier
> >> frequency
> >>
> >> I though jt65 would of out performed wspr ...be intresting to see the
> >> parallel decodes
> >>
> >> Tnx - G ..
> >>
> >>
> >>
> >>
> >> ----- Original Message -----
> >> From: "Andy Talbot" <[email protected]>
> >> To: <[email protected]>
> >> Sent: Saturday, March 22, 2008 7:03 PM
> >> Subject: Re: LF: Re: Re: WSPR == ON AIR TEST NOW 1545 HRS = 503 KHz
> >>
> >>
> >> > Hi Graham
> >> > Yes, I've got the right sequence time and am running WSPR and WSJT
> >> > 5.98 in parallel. Surprising the WSJT averaging won't extract a valid
> >> > decode. Some of the sessions are being tagged as having the sync
> >> > detected, with a resulting 2.5kHz S/N in the --25dB ballpark, but they
> >> > don't want to seem to be pulled together by the averaging. The DF
> >> > figure is coming up as -285Hz, suggesting you're 15Hz lower than
> >> > advertised (should be -270Hz)
> >> >
> >> > Do have very bad QRM here. I've just gone over to th the old 137kHz
> >> > antenna minus its loading coil rather than the HF vertical that was
> >> > the existing 500kHz Rx. The LF Tee is further from the house and
> >> > there is about 10dB less localised E field noise. Its a pity about
> >> > the deliberate jamming taking place just above the upper tone
> >> > frequency. I'm not sure how well JT65 can cope with that.
> >> >
> >> > Update on the WSPR decodes below - it really does seem a very good
> >> > weak signal mode. I'm just about to write June's Data Column for
> >> > radcom. I'll give WSPR a section having now played with it for a
> >> > while in real hard off-air conditions
> >> >
> >> > Andy G4JNT
> >> >
> >> > c:\WSPR>wspr Rx 0
> >> > 1750 8 -17 -0.1 0.001487 G0NBD IO83 37 28.3
> >> > 1752 6 -18 0.1 0.001487 G0NBD IO83 37 28.3
> >> > 1754 5 -20 0.0 0.001487 G0NBD IO83 37 28.2
> >> > 1756 3 -20 0.1 0.001487 G0NBD IO83 37 28.4
> >> > 1758 8 -18 0.1 0.001487 G0NBD IO83 37 28.9
> >> > 1800 8 -14 -0.3 0.001487 G0NBD IO83 37 30.1
> >> > 1802 1 -24 0.0 0.001487 28.7
> >> > 1804 4 -20 -0.2 0.001487 27.5
> >> > 1814 3 -22 -0.2 0.001487 28.1
> >> > 1816 1 -23 -0.6 0.001487 27.9
> >> > 1818 4 -24 0.0 0.001487 27.8
> >> > 1820 7 -19 -0.4 0.001487 G0NBD IO83 37 27.4
> >> > 1822 3 -24 -0.1 0.001487 27.6
> >> > 1828 2 -24 -0.3 0.001487 20.1
> >> > 1830 5 -23 -0.2 0.001487 G0NBD IO83 37 27.2
> >> > 1832 4 -20 -0.1 0.001487 G0NBD IO83 37 24.6
> >> > 1834 4 -24 -0.3 0.001487 G0NBD IO83 37 21.9
> >> > 1836 5 -23 -0.2 0.001487 G0NBD IO83 37 22.8
> >> > 1842 2 -24 -0.3 0.001487 G0NBD IO83 37 23.2
> >> > 1844 1 -26 -0.3 0.001487 22.3
> >> > 1848 7 -19 -0.2 0.001487 G0NBD IO83 37 21.9
> >> > 1850 2 -24 0.0 0.001487 24.0
> >> > 1852 7 -19 -0.1 0.001487 G0NBD IO83 37 27.3
> >> > 1854 5 -19 -0.1 0.001487 G0NBD IO83 37 23.5
> >> > 1856 3 -19 -0.1 0.001487 G0NBD IO83 37 24.9
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > On 22/03/2008, Graham <[email protected]> wrote:
> >> >> Ok Andy,
> >> >>
> >> >> Thanks for taking a look , the jt65 been running for a while now , did
> >> >> you
> >> >> have
> >> >> the 2 systems on when you decoded the wspr signals ?
> >> >>
> >> >> jt56 is sending at even mins , check the birmingham grabber , should
> >> >> show
> >> >> the 2 tone sets
> >> >>
> >> >> Tnx
> >> >>
> >> >> Graham ,
> >> >>
> >> >>
> >> >>
> >> >>
> >> >> ----- Original Message -----
> >> >> From: "Andy Talbot" <[email protected]>
> >> >> To: <[email protected]>
> >> >> Sent: Saturday, March 22, 2008 6:17 PM
> >> >> Subject: Re: LF: Re: Re: WSPR == ON AIR TEST NOW 1545 HRS = 503 KHz
> >> >>
> >> >>
> >> >
> >> >
> >> >
> >> >
> >> > --
> >> > No virus found in this incoming message.
> >> > Checked by AVG.
> >> > Version: 7.5.519 / Virus Database: 269.21.8/1338 - Release Date:
> >> > 3/21/2008
> >> > 17:52
> >> >
> >>
> >>
> >>
> >>
> >
> >
> > --
> > Andy G4JNT
> > www.scrbg.org/g4jnt
> >
> >
> >
> >
> > --
> > No virus found in this incoming message.
> > Checked by AVG.
> > Version: 7.5.519 / Virus Database: 269.21.8/1338 - Release Date: 3/21/2008
> > 17:52
> >
> >
>
>
>
>
--
Andy G4JNT
www.scrbg.org/g4jnt
|
