DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=googlemail.com; s=gamma;
        h=mime-version:date:message-id:subject:from:to:cc:content-type;
        b=uDuYOySKKLPAHXJTGCVGAgEtUxx0rWrFZEwIT3p9KvhL0bQkEkxtNFcqYcwmz7GFFF
         XTNSr9r3q9I8TLGzMcnxEtZt1k8FW5fiF7lJv19juQKmilEiJwpV5Z8724LWDRpPOjMe
         qUDB3zECRte29egj0v/jWcQmoqiGFHsrayfjw=
MIME-Version: 1.0
Date: Fri, 6 Mar 2009 11:03:41 +0000
Message-ID: <fc7eccec0903060303s443d8fbvd1083a6ff34f0e5f@mail.gmail.com>
From: Andy Talbot <andy.g4jnt@googlemail.com>
To: rsgb_lf_group@blacksheep.org
Cc: "jfell@tesco.net" <jfell@tesco.net>
DomainKey-Status: good (testing) 
Subject: LF: Multi-function beacon
Content-Type: multipart/alternative; boundary=001636c5a84edb64420464713c48
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org


--001636c5a84edb64420464713c48
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

I've now started transmitting a timed  beacon signal on 503.7kHz that
is identical in format to that of GB3SSS operated over the winter months of
the last two years  from Poldhu on 1.9 and 3.5MHz,  and has a similar signal
structure to the 5MHz beacons, GB3RAL, WES and ORK.  These all have an
initial CW ident and stepped power levels for aural reception, and a
precisely defined period of full-power plain carrier for S/N measurements.
See   http://www.rsgb-spectrumforum.org.uk/5mhz%20beacons.htm  for the
complete 5MHz  signal structure.  For this MF transmission, as on GB3SSS,
the pulsed sounder sequence of the 5MHz beacons is replaced with a PSK31
message which lasts from 30s to approx 48 seconds after the start

 Auto Monitoring software writen by G3PLX is available for monitoring these
beacons, it measures signal to noise during the carrier period and saves to
file as well as plotting the last 40 hours worth of measurements.
The software can be downloaded from
http://www.rsgb.org/spectrumforum/hf/beaconauto.php .   PSK31 data can be
copied with Digipan, Fldigi, PSK31SBW or a host of other packages.

*TIMING *
The 503.7kHz transmission takes place every 15 minutes at 4 minutes past the
quarter hour.
ie each transmission starts at *xx:04, xx:19, xx:34 and xx:49   * This time
slot has been selected so that the transmission do not interfere with my
continuous ongoing reception of the 5Mhz beacons - the active antenna used
for these is overloaded by the 500kHz signal and I have already lost data
when the WSPR beacon transmission coincided with one of the monitoring
windows.

NOTE   If using the G3PLX software, this only monitors for the three 5MHz
beacons at  00, 01 and 02 minutes.
*SO IT WILL BE NECESSARY TO FRIG THE SOFTWARE * to monitor this transmission
at the 04 minute point.   The necessary alteration can be done by firstly
setting your PC clock accurately to the correct time, then setting the Track
Time box to -240 (minus 240 seconds).  This will make the software look for
this transmission during the time window it thinks it would be receiving
GB3RAL, and log the MF transmission during the first minute, on the red
trace, as if it were GB3RAL

The beacon uses the identical hardware to the WSPR transmissions of the last
few weeks, with the the only change being a reprogramming of the controller
PIC.   In fact the very same hardware was previously loaned to the Poldhu
club for their beacons, with the only difference being a change to the final
Low Pass filter on the output of the broadband PA.

 Andy  G4JNT
www.g4jnt.com

--001636c5a84edb64420464713c48
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div>I&#39;ve now=A0started transmitting a timed=A0 beacon signal on 503.7kH=
z that is=A0identical in format to that of GB3SSS operated over the winter m=
onths of the last two years=A0=A0from Poldhu on 1.9 and 3.5MHz, =A0and has=
=A0a similar signal structure to the 5MHz beacons, GB3RAL, WES and ORK.=A0 T=
hese all have=A0an initial CW ident and=A0stepped power levels for aural rec=
eption,=A0and a precisely defined period of full-power plain carrier for S/N=
 measurements.=A0=A0</div>

<div>See=A0 =A0<a href=3D"http://www.rsgb-spectrumforum.org.uk/5mhz%20beacon=
s.htm">http://www.rsgb-spectrumforum.org.uk/5mhz%20beacons.htm</a>=A0 for th=
e complete 5MHz =A0signal structure.=A0=A0For this MF transmission, as on GB=
3SSS, the pulsed sounder sequence of the 5MHz beacons is replaced with a PSK=
31 message which lasts from=A030s to approx 48 seconds after the start</div>

<div>=A0</div>
<div></div>
<div>Auto Monitoring software writen by G3PLX is available for monitoring th=
ese beacons, it measures signal to noise during the carrier period and saves=
 to file as well as plotting the last 40 hours worth of measurements.</div>

<div>The software can be downloaded from=A0 <a href=3D"http://www.rsgb.org/s=
pectrumforum/hf/beaconauto.php">http://www.rsgb.org/spectrumforum/hf/beacona=
uto.php</a>=A0.=A0=A0 PSK31 data can be copied with Digipan, Fldigi, PSK31SB=
W or a host of other packages.</div>

<div>=A0</div>
<div><strong>TIMING </strong></div>
<div>The 503.7kHz transmission takes place every 15 minutes at 4 minutes pas=
t the quarter hour.=A0 </div>
<div>ie=A0each transmission starts at <strong>xx:04, xx:19, xx:34 and xx:49=
=A0=A0=A0</strong>=A0This time slot has been selected so that the transmissi=
on do not interfere with my continuous ongoing reception of the 5Mhz beacons=
 - the active antenna used for these is overloaded by the 500kHz signal and=20=
I have already lost data when the WSPR beacon transmission coincided with on=
e of the monitoring windows.</div>

<div>=A0</div>
<div>NOTE=A0=A0 If using the=A0G3PLX software, this only=A0monitors for the=20=
three 5MHz beacons at =A000, 01 and 02 minutes.</div>
<div><strong>SO IT WILL BE NECESSARY=A0TO FRIG=A0THE SOFTWARE </strong>=A0to=
 monitor this=A0transmission at the 04 minute point.=A0=A0=A0The necessary a=
lteration can be done by firstly setting=A0your PC clock accurately to the c=
orrect time, then setting the Track Time box to -240 (minus 240 seconds)..=
=A0 This will make the software look for this transmission during the time=
=A0window it thinks it would be receiving GB3RAL, and log the=A0MF transmiss=
ion during the first minute, on the red trace, as if it were GB3RAL=A0</div>

<div>=A0</div>
<div>The beacon uses the identical hardware to the=A0WSPR transmissions of=
=A0the last few weeks, with the the only change being a=A0reprogramming of t=
he controller PIC.=A0=A0 In fact the very same hardware was previously loane=
d to the Poldhu club for their beacons, with the only difference being a cha=
nge to the final Low Pass filter on the output of the broadband PA.</div>

<div>=A0</div>
<div></div>
<div>Andy =A0G4JNT</div>
<div><a href=3D"http://www.g4jnt.com">www.g4jnt.com</a></div>
<div></div>
<div></div>

--001636c5a84edb64420464713c48--