Hi Joe ,
Well its mid summer again !
Best I advice I can give is head for the middle of the two bands ,
op32 137.55 or op08 137.65 , this allows for any off sets in the the
Rx side etc, 5 or 10 Hz off the band edges should give full
performance, Op is about 2 Hz b/w so there is very little chance of
'doubling' in the classic , way .
One thing to check is resident carriers in the pass band , I think
Marcus has indicated there are some loran lines in band , further
over may be some of the Russian stations can indicate if there is a
problem, once again , more than a few Hz will not cause problems
There is good chain of Op32 monitors from the uk west coast out to
the east , so you should see good results, also inside the USA and
across to west coast , not to mention Laurence up in Alaska , at
least with the 50% duty cycle it will keep the heat down !
if your TX p/c is not web linked . there will be no tx beacon or
decode spots , but its possible , to run the windows app on a web
linked pc set band and set the tx timer - beacon on , sync with the
tx driver , that way you can send the tx beacon ( will indicate
op8 or op32) and collect the decode spots via the web directly , as
there is no time locking , the tx beacon is just for indication
Where as Op is designed to use standard tx/rx and soundcards with
afc routines , Marcus is running a correlation process , looking for
the pattern match , this in effect is decoding a single data 'bit'
and stability will affect his decode system , but with another 10 dB
s/n it may extend the range considerably !
Good luck and 73
Graham
G0NBD
OP32 137.5 137.6
OP08 137.6 137.7
--------------------------------------------------
From: <[email protected]>
Sent: Thursday, June 06, 2013 5:26 PM
To: <[email protected]>
Subject: Re: LF: VO1NA - 137.7770 kHz
Hi Andy and thanks for the report and gratifying info on the stability.
It seems to be working quite well and the frequency reports are
very good, given that the DDS resolution is about 15 mHz.
To Jay, thanks for the info on your RX ant. This explains why the sigs
are not seen sometimes, but there is still some directionality with
the wire (assuming the tower to be omni). The wire actually appears to
have some gain towards the east, but is weaker than the tower towards
the west. The wire is also lower than the tower.
Graham, G0NBD, could you suggest a good QRG for OP32 now that the TX
is no longer rock bound on 137.777 kHz as it has been for the past decade.
Incidently, last month marked the 10th anniversary of the reception by
Alan, G3NYK of my QRSS75 on 137.777 kHz. This was the first TA signal
received from NL Canada. The source was an old Peggelsender running on
13.7777 kHz divided down by a pair of 7490 decade counters. It was not
very stable and so was replaced by a 13.7 MHz xtal in a ocxo.
The TX will be on again tonight with hourly QRSS30 starting 0000 utc.
73 & GL
Joe VO1NA
On Thu, 6 Jun 2013, Andre Guyé wrote:
Hello Joe,
No problem. As usual, your QRSS signal gave here a strong trace this
morning with peak around 0230 TU. Stable signal better than .005 Hz / 2
hours, no chirp.
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