Re: [amsat-bb] : DSLWP: First Amateur Radio Transmissions from
Bob:
Thanks very much for the detailed reply! I'm sure I'm not the only appreciative reader either.
So from your description it sounds like a station with approximately 1/4 the antenna elements typically considered necessary for closing an EME echo path on CW might be the lower margin of success. I have had 22 elements in the air on 70cm before but not now unfortunately, and not on an "EL" rotor before. I have some work to do.
I'm not familiar with the Airspy's dynamic range off hand, but the RTLSDR's is not great. Seems like SDRs with a few more sampling bits would provide a leg up like the Lime.
Anyway, it certainly helps to know where to start. Thanks again!
73; Bob KV4PC
On Wed, Jun 6, 2018, 11:36 PM N6RFM1 gmail n6rfm1@gmail.com wrote:
Hi Bob,
As you have read in earlier posts, several of us (and the list grows slowly I think) have been able to both receive and decode signals. My understanding is that early in the launch PY2SDR, CD3NDC, PY4ZBZ, K4KDR and myself received signals. By some quirk of fate, I was able to report the first properly decoded packet back to the team’s server.
The setup here – 11 elements on 70cm (custom “Alaskan Arrows” with solid elements), SSB E. SP-7000 on UHF preamp, 28 meters of ½ inch hardline, bias-T,
Airspy rtl-sdr dongle. Not a superstation by any stretch.
At this point the DSLWP-B is in a lunar orbit. While DSLWP-A has been reported on S-band, we don’t know its status or location.
See http://destevez.net/2018/06/dslwp-bs-journey-to-the-moon-part-iii/ for much more detail. This blog reflects a tremendous effort by many experts including EA4GPZ, BG2BHC and Scott Tilley, among others. (Early this year Scott discovered that the “long dead” IMAGE satellite was in fact alive.)
The DSLWP team has now conducted several tests after the lunar injection. Cees Bassa and Jan PA3FXB have had some amazing results with the Dwingeloo radio telescope in the Netherlands, during a lunar test window a few days ago. Alas, we can only dream of such an antenna, and place to put it!
Perhaps more relevant to your question - a very big round of applause for Piotr SP5ULN who was successful with a decode from the lunar orbit. Piotyr’s setup is a Cushcraft 719B 19 el Yagi, SSB Electronics LNA (SP-7000), 30m of RF-10 coax, bias tee and simple RTL-SDR. So, we remain hopeful… Others may have also been successful, but the DSLWP telemetry server seems to be down and I can’t tell if there were any other recent contributors. Perhaps Wei BG2BHC will give us another update and we can find out what the setup was.
BTW, there is another test and hopefully some of the friends in Japan will be successful too.
One more point, as far as I am aware only GMSK has been transmitted. But, there is also a JT4G transmitter on –B. Hopefully, JT4G will be easier to receive. I for one hope that will be the case.
73,
Bob
N6RFM
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Robert Ehresman