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Re: LF: Re: Opera v qrs evaluation

To: <[email protected]>
Subject: Re: LF: Re: Opera v qrs evaluation
From: "mal hamilton" <[email protected]>
Date: Wed, 1 Feb 2012 10:04:49 -0000
References: <006201cce044$06c16f80$0401a8c0@xphd97xgq27nyf> <3A9A60CAE4EB4355A5B0A30CDA0F450A@JimPC> <AE79F5BD0B964D4CBF8E04AD01E73808@JimPC> <[email protected]> <001b01cce0c1$49ec88d0$0401a8c0@xphd97xgq27nyf> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
I would say your qrs on 500 was heard/seen but no one could be bothered to
report it.
I personally do not report QRS beacon acty on any band.
The majority of 500 Beacons are normal CW and I can hear the USA and Canada
frequently and strong enough for a QSO
I thought a PIC was an implement to dig a hole with !!


----- Original Message -----
From: "qrss" <[email protected]>
To: <[email protected]>
Sent: Wednesday, February 01, 2012 9:29 AM
Subject: Re: LF: Re: Opera v qrs evaluation


> Mal
>
> Fact. Everyone including G3KEV has missed my QRS3 and QRS10 on 500kHz
> every time I have had it on, using this same TX, in fact I removed the
> PIC which sends the QRS and inserted OPERA, viola PA0's at 493km decode
me.
>
> Please be technical not emotional about the subject it doesn't help.
>
> 73 Eddie
>
>
> On 01/02/2012 09:10, mal hamilton wrote:
> > QRSS does NOT get lost or missed  in the noise as you suggest and one
can
> > always see at least part of the information trace, whereas Opera is all
or
> > nothing and I have noticed at times a TRACE but NO DECODE.
> > I wonder what your next distortion of the facts will be
> > g3kev
> >
> > ----- Original Message -----
> > From: "qrss"<[email protected]>
> > To:<[email protected]>
> > Sent: Tuesday, January 31, 2012 11:37 PM
> > Subject: Re: LF: Re: Opera v qrs evaluation
> >
> >
> >> Dear Jim, Rik, Laurence
> >>
> >> Thanks for the information, it does seem from all tests that QRS3 and
> >> OP4 are about equivalent.
> >> QRS as we know takes a human to notice its there among noise and can
get
> >> missed. With OPERA (and WSPR) if there is an RX on in range it's
de-coded.
> >>
> >> 73 Eddie G3ZJO
> >>
> >>
> >> On 31/01/2012 22:51, James Moritz wrote:
> >>> Dear Eddie, LF Group,
> >>>
> >>> I did a rough and ready comparative test on the "sensitivity" of QRSS3
> >>> and Op4 using your back-to-back transmissions. For 500kHz reception,
> >>> broadband noise from the broadcast stations just east of here is being
> >>> nulled out using a loop oriented N-S. Rotating the loop out of the
> >>> null position gives a convenient way of adjusting the SNR on Eddie's
> >>> signal. So I increased the noise level until I judged Eddie's QRSS was
> >>> just fully readable (using 0.3Hz FFT resolution), then left everything
> >>> in the same position for 4 transmissions, during which signal and
> >>> noise levels stayed nearly constant (see the attachment). Opera
> >>> reported an SNR of -31dB on Eddie's Op4 signal for all the
> > transmissions.
> >>> So, from what Graham said, Op4 may have a small margin in SNR with
> >>> these conditions. You could argue about what constitutes "readable"
> >>> QRSS, but there can't be more than a few dB difference between this
> >>> signal and something indecipherable without prior knowledge. It takes
> >>> 4 minutes to send a callsign using Op4; you could increase the dot
> >>> length perhaps to 4s  and transmit most callsigns in 4 minutes, which
> >>> would gain you about 1.2dB. But for practical purposes I think, in
> >>> this test anyway, the two modes are approximately equivalent in their
> >>> efficiency in sending callsigns.
> >>>
> >>> Cheers, Jim Moritz
> >>> 73 de M0BMU
> >>
> >
> >
>
>



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