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LF: Re: RE: DCF39 now 21 db above the noise!

To: [email protected]
Subject: LF: Re: RE: DCF39 now 21 db above the noise!
From: "Larry Kayser" <[email protected]>
Date: Sat, 12 Feb 2000 09:18:14 -0500
Reply-to: [email protected]
Sender: <[email protected]>
FB Larry! Please continue the experiments. It is essential to learn the
propagation paterns and fading phenomena. I would like to take a look at
one
of your .WAV files.

The sample WAV file is large, 800K, will send separately to anyone who wants
it.

For the record:
In the Netherlands DCF39 is S9+50dB. The strongest German stations located
near DCF can make signals at a level near S9! This indicating a relative
ERP
level of approx. -50dB. At the 21dB above noise from DCF39 in Canada we can
estimate the Radio Amateurs at 29dB BELOW! noise level. If DCF is monitored
already at minimum bandwith and with maximum noise reducing techniques i am
afraid we still have to figure out how to dig deep into the noise and
detect
the signals.

I agree that we need some help from technology.  I think however that the
Swedish guys last weekend had a good idea, excellent idea, excellent way to
knock off 10 to 15 of those DB's that keep getting in the way.  My receiving
system here is not optimized yet either.  I know I can do better on the RX
side, a lot better.  What we need today is a box that one can hook in the
feedline to the antenna and what comes out is minus the Loran-C garbage.
The Loran-C garbage to come out the port with the 50 ohm resistor on it!
When I first did single yagi EME I was told it would not work, I would never
be heard.  When I used a large lake over here to provide a perfect ground
reflection gain I worked EME easily, the db problem had gone away.  LF is no
different, let us together find out how to move those dB's around to our
advantage.

Who has experience with <-29dB to noise level signal identification?
CoherentCW, PSK, SlowCW, dedicated DSP algotithms? There are lock-in
amplifiers using similar techniques maybe we can benifit there.

Yes, some of this will help.  We need basic tools as well,  DSP Programs for
us that will monitor DCF39, record the signal levels regularly and send an
alarm when the signal peaks above a set threshold.  For your side, the same
but monitoring CFH.  When we understand the propagation behaviour over the
North Atlantic we will solve the riddle of having a QSO.  In an Economic
sense - when we have perfect information we will do the trick that wants to
be done.....

Best 73's and gl on lf
Michael Sanders, PA3BSH

Yes, I am looking forward to working with your side of the Atlantic.  Lots
to do for those who are game to do it.  Today I am off to find a 40 ft long
insulated mast I can hang a 25 ft diameter single turn receiving loop on, as
I said the receiver side here needs more work.

73 for the moment.....

Larry
VA3LK



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