Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: LF: Re: Opera v qrs evaluation

To: [email protected]
Subject: Re: LF: Re: Opera v qrs evaluation
From: qrss <[email protected]>
Date: Wed, 01 Feb 2012 10:29:26 +0000
In-reply-to: <004301cce0c8$ef41a700$0401a8c0@xphd97xgq27nyf>
References: <006201cce044$06c16f80$0401a8c0@xphd97xgq27nyf> <3A9A60CAE4EB4355A5B0A30CDA0F450A@JimPC> <AE79F5BD0B964D4CBF8E04AD01E73808@JimPC> <[email protected]> <001b01cce0c1$49ec88d0$0401a8c0@xphd97xgq27nyf> <[email protected]> <004301cce0c8$ef41a700$0401a8c0@xphd97xgq27nyf>
Reply-to: [email protected]
Sender: [email protected]
User-agent: Mozilla/5.0 (Windows NT 5.1; rv:9.0) Gecko/20111222 Thunderbird/9.0.1

But but but but, how do you know some QRS is a Beacon until you notice it and decode it. You Mal then normally post a comment about the 'time an band width waster'. I am pretty sure that until yesterday you had never seen my signal on 500kHz. Remember you did order me off 500kHz with my 'band width wasting WSPR' when I first got my NOV without even seeing my signal.:-)

Eddie

On 01/02/2012 10:04, mal hamilton wrote:
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







<Prev in Thread] Current Thread [Next in Thread>