Basically, correct - if you transmit 10B/s PSK on 137kHz without any bandwidth
filtering people get a bit upset. We did look at turning it into some phase
continuous mode - CPM - but there seemed to be little interest in advancing the
technology. Likewise GPS locked BPSK - straightforward, very robust and
bound to give vastly superior weak signal performance, but more than the
average plug-and-play mode.
I've been doing a lot with GPS recently (for professional purposes, not for
play) and currently have access to five different types of GPS module - all low
the cost ones. They're getting very, very small now - some are postage stamp
sized. In terms of ease of use though, as far as amateurs are concerned, I'd
go with the older Garmin GPS25 module any day! All the other ones have to, at
least initially, be programmed in complex binary mode before the simple data
output format of NMEA can be enabled. FUrthermore, the later modules operate
LESS well with poor signals and partially obstructed view of the sky than the
latest 12 satellite simultaneous view machines do.
Just a quick observation and will bear further experimentation, if possible to
do so.
Andy G4JNT
-----Original Message-----
From: Alan Melia [SMTP:[email protected]]
Sent: 2004/01/12 14:11
To: [email protected]
Subject: LF: Re: Re: First WOLF QSO!
Hi Ed, as John says, I do not recall any two-way WOLF qsos. I think only Jim
M0BMU, Andy G4JNT have transmit it, that I can remember. It is basically an
"off-line" decoding system, where with weak signals one may have to process
the recorded file several times. I think a lot of us were waiting and maybe
hoping for a "instant", real-time version. Then Alberto came along with
Jason as a keyboard decoded mode, and WOLF did not seem to progress.
(Stewart provided some adaptive code to improve the decoder in Alberto's
system) I also believe that WOLF is transmit as BPSK which generally
requires a linear PA. (Jason is an FSK mode so can use non-linear PAs)
Generally for high power station one requires a DDS exciter with a non
linear PA, to prouce "soft" phase transitions. It is possible with some
hardware that Jim developed to produce soft phase changes which would be
required on a high power station to control bandwidth. I dont think the
bandwidth is such an issue with FCC Part 15, 1 watt output, stations.
Details from memory (liable to suffer dropped bits these days ...:-)) Look
at
http://www.scgroup.com/ham/wolf.html
for the full story.
Well done on repairing the aerial at Machta and we look forward to hearing
your signals again.
Cheers de Alan G3NYK
[email protected]
----- Original Message -----
From: "Ed Lesnichy" <[email protected]>
To: <[email protected]>
Sent: 12 January 2004 11:17
Subject: LF: Re: First WOLF QSO!
John, Dex and LF-enthusiasts!
My congratulations to John W1TAG and Dex W4DEX!
It is remarkable result at such very small ERP!
I believe what to RX a very weak signal at 1w DC input max (not 1w
ERP!!), and antenna less than 15m on distance abt 1080km it is very
difficult in any modes...probably in WOLF is especial...and at the
daytime...
On what greatest distance it was possible to RX in long QRSS such small
ERP at night?
US's Lowfers have saved wide experience in reception of very weak
signals on LF - when already they will appear on 136 or 160-190kHz for
longway 2-way QSO with high-grade ERP?
The first(?) reception of Europe signal in North America on WOLF:
John W1TAG RX Jim M0BMU at March 9, 2001 at QRB abt 5307km
Whether who has made 2-way QSO on WOLF in Europe?
When (date) Stewart KK7KA has made WOLF mode?
73! Ed RU6LA [email protected] http://136.73.ru
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