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The start of this test to see if Bill W4HBK and I
could get my QRSS Signal from Las Cruces, New Mexico to Pensacola
Florida, a distance of 1,164 miles at a power level of 1 microwatt.
We started in November of 2013. We started the test at about
100uW on 30M with this test setup. It is a Hans Sommers Ultimate,
some attenuators, and my M cubed Power Meter/Frequency Counter.
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This setup worked pretty well until the middle of December
the variations in temperature in my garage shop was causing the
frequency and the 10 minute repeat timing to vary. To counteract
the temperature changes, I built a foam cocoon for the transmitter
to live in. This worked for a while longer but it wasn't tight
enough or thick enough to provide a stable temperature vessel.
Here is a picture of this configuration.
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Along about the middle of February, I acquired a Hans Sommers
Ultimate 2 from my friend NM7J and built it up with its 9850
DDS Oscillator and set it up to run on the 30M frequency with
the 10 minute interval and using my Trimble GPS 1 PPS to stabilize
it. It automatically calibrated the unit and from then on my
frequency and transmitting timing were spot on. By this time
we were getting down into the 25uW and lower ranges but the propagation
was really being ustable with lots of solar flares and no signals
were getting between us. I made a new cabinet for my new transmitter
out of a $2 cardfile cardboard box, alumimum tape, and some presentation
foam board. I also found a Omaha Steaks shipping container that
was a much better thermal container than my pink cocoon. The
final transmitter configuration is shown here.
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The lowest we could get on 30M was 15uW on 3/3/2014.
Try as we might we just couldn't get a lower signal level. The
noise, QRM from WSJT JT65A and being clobbered by Over the Horizon
Radar signals made the task very difficult. Plus, we were running
out of time as the spring storms and summer noise was about to
pickup at W4HBK's site in Pensacola. Here is the stack of the
15uW 30M signal that we were working with: (The thing that makes
me most proud of this screenshot is the pencil thin lines of
my signal - this means that the frequency was ROCK stable and
the 10 minute repeat cycle was very exact. I think that this
is a stack of 22 separate images. Even though the signal was
weak, it was still very distinct.)
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Because of the 30M QRM problems and being stuck and
not being able to copy anything lower than 15uW, Bill W4HBK suggested
that we move to 20M to see if it was any better. The frequency
is a lot clearer and there wasn't any WSJT JT65A traffic. Plus,
I have a 3 element beam that could be used to boost the signal
some 8dB. So, we went to 20M and reset the test transmitter to
23uW to see if it could be copied. In quick sucession we went
from 23uW on 4/24/2014 to 3.12uW on 5/5/2014. Its screen shot
is below.
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Now is it really getting tough. The noise at W4HBK's Pensacola
location is really starting to become a problem even on 20M and
we still had one more 3dB step to go. The space weather was being
active with a number of sunspots spitting out numerous C and
M class flares and the A index was above the 7 mark for most
of the time. Every once in a while there would be what Bill refered
to as Magic Propagation. My 1uW signal would come out of the
noise for a 1 or 2 minute period and you could see it without
any aids. Unfortunately, These periods were not long enough for
my whole call sign which takes about 7 and one half minutes to
complete. So we needed a good quality, long period where my signal
was visible on W4HBK's 6 Hour grabber display so he could pick
the time periods he wanted to use to stack to bring my signals
out of the noise. This event happened on 5/17/2014. My signal
was visible on the 6 hour display for over 3 and 1/2 hours and
Bill was able to gather up enough 10 minute segments to stack
to bring the signal up out of the noise. Here is the 6 Hour display
from 5/17.2014:
Here is the stacked image of those 10 minute screenshots
and what we worked so hard for 6 months to get:
The above screenshot is the result of 6 months of work
generating the signal and copying it over a 1,164 mile path between
my house in Las Cruces, New Mexico and W4HBK's house in Gulf
Breeze, Florida. We did it through wind storms, hail storms,
Bill went through multiple tornados and a flood. Cold nights,
Antenna repairs when Bill's racoons decided that they needed
to rewire his antennas. Battling the swamp, posionous snakes,
hot sun, Equipment failures, unpredictable propagation, Massive
QRM from Over the Horizon RADAR, a Lightning Strike on Bills
Station. Just about everything that can happen ... DID. But through
all of that, We still accomplished what we both thought of as
impossible... 1,164,000,000 Miles per WATT. Using a measured
.000001 Watt signal to the antenna. We have applied and are waiting
for our QRSS certificates from the QRP ARCI. It is an amazing
accomplishment that I am still trying to get my brain around.
THANKS BILL W4HBK FOR A FANTASTIC RIDE. |
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W4HBK'S QRSS RECEIVING STATION
A picture of W4HBK's Shack needs to be included to
give you a complete picture of the whole test setup. We both
are just using standard Amateur Radio equipment that has been
modified for the stability and frequency control to do these
type of experiments. Below is a picture of Bill's shack:
The litte vertical box with the yellow LED is Bill's temperature
control unit for the Master Oscillator of his Kenwood TS-440S.
He has that receiver stable to within 1 Hz. The information on
his Temperature control system for this transceiver can be viewed
at his
blog. His DDS controled Manned Experimental Propagation Transmitter
is the unit just above the Heathkit HW-8. The screen is displaying
the Spectrum Lab program by Wolf Buescher DL4YHF and his excellent
tips for using this program can be viewed on his
blog. |
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The picture below shows Bill's very excellent antenna farm
that he uses for his excellent PENSACOLA SNAPPER GRABBER. With
these antennas and a Antenna Tuner, He covers all bands and has
copied many weak QRSS and WSPR signals from all over the world.
It is really amazing how very well this antenna system works.
Bill's Blog site is a wealth of technical information for
most operations associated with QRSS. He has excelled in his
study of this very weak signal mode and the physical effects
that are seen on the air. He is always willing to help the newcomer
and the old timer. His Grabber THE PENSACOLA SNAPPER is always
on the air giving us all a known site to check our
transmissions. You can visit his BLOG site HERE.
You can find his PENSACOLA SNAPPER GRABBER at this SITE.
For Bill's Version of our "Adventure" check out
his blog site HERE |
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The 1,000 Mile Per Watt
Certificate for a
1.164 Billion Miles
Well, Above is the 1,164,000,000 Miles per Watt certificate
issued by the QRP Amateur Radio Club International after submission
of our data from the 1uW one-way contact between W4HBK and myself.
It is a mind boggling accomplishment to me as I really didn't
think that it was possible. But I don't think this is the end.
As more Amateur Radio Operators become interested in QRSS and
the advancing technology of Spectrum Analyzers and Receiving
Techniques. This accomplishment will be eclipsed hopefully many
times. As long as there are inquisitive minds who wonder if it
can really be done, There will always be those trying to do it.
So, Bill and I have shown it can be done at this RF power level.
Who is going to be next to better it?
73 Dave WA5DJJ |
