Jim et al:
First, I had a power failure yesterday. When I put the DDS back on line the
best I could do according to Bill de Carle was as follows....
"he's presently on 137,789.40 [0010 UTC]"
I will try and avoid messing this setup over this weekend. I am sending
continuously now, 90 second carrier with 90 second space.
I am trying today to quickly implement both 90 and 270 second carriers with
90 second spaces. If I am able to get this reliable today I will put it in
place by 21 utc for the rest of the weekend. If this happens I will put a
short note on the RSGB reflector to that effect.
Amongst other things, there were 2 continuous traces spaced by
about 0.1Hz, virtually astride the nominal frequency. These faded in
and out in a DX fashion. Also, there was a train of dashes and
spaces of 90s +/- several seconds duration. I estimated the
frequency to be 137.7894kHz, give or take about 0.1Hz. These
were also fading; there were several short periods of good
reception during the night between midnight and 0700, and one
long period between 0145 and 0300 when the signal was
strongest. I was using DL4YHF's "Spectrum Lab" software, set to
0.042Hz resolution and averaging over 2 FFTs; the SNR with these
settings was about 5-10dB, so quite clear.
The real issue is, what is the absolute frequency I am on and your listening
to and are they the same. I am working to get converted over to the G4JNT
DDS board with my Sulzer Labs frequency standard as the reference. When
that happens we will have rather excellent frequency control and
resetability over here. Now, I have no real control below 1 Hz resolution,
which is very good but no longer what I now need hi.
I don't know if this was VA3LK, the -0.6Hz seems rather large for
an error - perhaps Larry could confirm or deny. If they were not
VA3LK, it would be worth looking at what frequencies to avoid in
future tests. Neither the dashes or the continuous lines were
connected with the local Loran, I was able to check this by altering
the direction of the loop antenna.
Well if I look at your difference of .6 Hz and Bill de Carle's mesurement of
me being low by .6 Hz (after my power failure) we probably have agreement on
what you were watching. My sense is I should offer you Congratulations -
but maybe we should wait a bit longer for that.
Your effort is appreciated so very much - I do hope that I can make my
signal identifiable, I will try to get the two lengths of carrier
implemented today then you can have another run at the signal over the
weekend.
We have had some freezing drizzle here overnight and I am going up to the
remote site to see what effect that has had on the antenna current (I am
recording the antenna current every 10 seconds now), if that looks
manageable then I will start pushing the amplifier a little harder. My
loading coil is now uncovered, wide open, as the old cover melted (a plastic
laundry tub, large economy size hi) and I had to peel what was left of if
off and take it away. I have a sense that I should make a new cover / small
shed, to cover the loading coil. What I am waiting for is a consensus to be
arrived at as to what I should use for building materials. At the moment if
I have it right, I should line the inside of the cover / shed should be
lined with aluminum foil, my question is do I need to bond the foil together
and to ground or is it enough to just have it surrounding the coil?
Regardless Jim, your effort is greatly appreciated. What else besides the
two lengths of carrier can I do to make the signal more easily seen on your
system?
Larry
VA3LK
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