[NLRS] Beacon Question and a Modest Proposal
Doug Reed
n0nas at amsat.org
Fri Sep 23 14:47:49 EDT 2011
Hi Bill.
Interesting issue about the beacon frequency restriction.... Maybe that
is only for CW beacons? I know that <http://propnet.org/> has been doing
automated PSK31 propagation beacons on most bands. On 6M they are up at
50.291MHz. I had a PropNET 6M packet beacon station on the air before that.
As for the beacon mode, I'd say stay with CW if you want something that
anyone sitting at the radio can tune in and use. But if you want
something that will be an automated propagation beacon, then choose
either WSPRnet or PropNET. Both systems are digital beacons that listen
for other stations as well as transmit your beacon several times an
hour. Both systems report back to a central Internet site saying what
they heard and anyone can access the results on a real-time map from
their web site. So far both systems are independent and don't share
their info.
Personally, I like the glitz and eye candy of the WSPRnet web page but I
prefer the PSK31 mode used by PropNET. The main reason for my choice of
PropNET over WSPRnet is that WPRSnet can decode signals about 24dB below
the noise floor while PSK31 can dig down about 17dB below the noise.
Since I want my propagation beacon to be useful to people running 50-100
watts of SSB, I need to limit the beacon power according to those
figures. That means my PSK31 beacon should be 1 watt or less, a WSPRnet
beacon should be UNDER 100mw......
In similar fashion, I'd suggest a 6M CW beacon should be under 25 watts.
If it is heard reasonably well, that would indicate that a SSB QSO could
probably be made with 25-50 watts or more.
Back when I had the PropNET FM packet beacon station on the air, I think
I was running 25 watts from the radio. My reasoning is that FM needs a
fairly strong signal in the .5 to 1uv range to decode a packet message.
So if my 25W packet beacon was received, I know that a SSB QSO should be
possible with a similar power level. But PropNET doesn't use FM packet
beacons any more....
So if you want a beacon that anyone can tune around a radio and hear,
stay with CW. But if you want a beacon that anyone can check on the
Internet, choose PropNET or WSPRnet. So far there are not a lot of
people using 6M with either system. Most PropNET and WSPRnet activity is
on 10M or 30M. WSPRnet has a better international following,
particularly on 30M. They may be about equal on 10M.
Those are my opinions regarding beacons. Probably the biggest thing I
have against either system is the need to dedicate a fairly fast
computer and a decent sound card to either mode. And the need to use a
SSB radio. A CW beacon transmitter can be a lot simpler and could be
built from an old commercial FM radio if you wanted to.... Although
you'd probably want use a crystal oven or replace the crystal with a
more stable oscillator.
Good luck with the project!
73, Doug Reed, N0NAS.
Bill Ockert wrote:
> I have been considering a 6m beacon for EN07 for some time but rather than
> sticking with the
> traditional CW beacon I was thinking of an updated one. With the technology
> that the WSJT
> protocols made available and the margin that those protocols provides there
> are likely potential
> openings that are being missed.
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