Friday, 17 August 2012

Reflections from D64K Part 2

I was in the shack at 03:30 AM local for another attempt this morning. The band noise was exceptionally low in the direction of Comoros. After 1 hour of FSK441 I gave up. Nothing was heard or seen from D64K. To be honest I have a feeling there was no one on the other side. I guess they needed sleep more than I needed the MS QSO.

Since my first posting we have had several further attempts at completing a QSO via meteor scatter without much success. The accumulated time most likely exceeds 6 hours of WSJT FSK441 of rapid “machine gun fire”

To succeed with stretching the distance requires the following:
Heightened meteor activity such as provided by Perseids MS, well equipped stations with high ERP and lots of patience. A shower with a radiant south of the equator would also be most beneficial.

I discovered a very interesting web site that shows real time data of radio reflections from meteors. Using this info it clearly shows that the prediction for the peak activity for Perseids was spot on.

The best decode I received from D64K and the record breaking (South African) QSO that took place between Braam ZS6AYE and Comoros took place at the peak of Perseids MS on 12 August at 11:30 UTC. If only we tried 10 hours earlier........

With regards to the best mode to used, that is pretty much a contentious issue. I am a bit old school I think FSK441 still is the best IMHO. Better still if we were not so dogmatic that a QSO must consist of the exchange of calls and a report (or other bit of information) it would be much easier. Anyone that has ever played with WSJT software will know just how effective the ST- Single tones are. If the only requirement was to positively ensure that a two way radio path existed then using the single tone or the dual tones “railway tracks” would be most effective. It is uncanny to see how well that works compared to all the other high speed modes.

Some you win some you lose……

Josep EA3AKY the 6m operator on the D64K DX expedition has excelled at his task.
Thanks for the opportunity of trying to do the impossible and your patience and willingness to try.


 Congratulations to Braam, ZS6AYE, and D64K on Comoros Island for establishing a new 50 MHz digital record in the early morning of 14 August 2012.  The new record of 2011 km was accomplished on FSK441 during the current Perseids meteor shower, and broke the old record of 1929 km set up in 2003 by ZS2BWB and TO4E.

MS activity Perseids peak 12 Aug 2012

Monday, 13 August 2012

Reflections from D64K

A while back, I saw a posting on the D64K - DX expedition to Comoros Islands web site. It was obvious that they were very well equipped for 6m. They had a serious antenna; low loss feed lines and some power to boot. The plan was to operate EME at their moon rise and moon set, some TEP/F2 work and possibly MS work into Africa.

I determined that the distance was 2,247 km from my QTH. After speaking to some of the local VHF doyens my initial excitement was a bit dampened. They thought that it was just a bit too far and my expectations were unrealistic.

Yesterday I saw on the reflector that they were beaming towards Africa using FSK441. Due to some confusion it turned out we were all transmitting in the same period. After 30 minutes, I stopped transmission and decoded a ping from them. Only after the sked did I realize that the 140 ms long ping contained the full call and grid locator. See screen shot below. I immediately arranged for a further sked.

We have just completed another marathon session of 1 hour and 20 minutes. I received absolutely nothing from them this morning. After we quit, I received a message from them stating that they decoded 4 pings from me, the longest being 2 seconds long. This was incredibly good news!

I believe we have a real chance at completing a MS QSO, we just need patience and a few rocks from the Perseids meteor shower……

After looking at the South African VHF records, I now understand why the doyens were skeptical. The record distance via meteor scatter is only 1,929 km

Good thing I did not see this before……

ZS6A - D64K 6m MS 2,247 km

Thursday, 9 August 2012

“CQ DX4U EU up”

The DX stations often in an attempt to control the size of a pileup by using directional call e.g. “NA up” for example. The problem is the ‘wall’ created by Europe or the Americas or Asia can be substantial, so it is quite understandable that the DX operator will make use of the directional call system.

There is however a problem with this system. The operators very seldom if ever will call “AF”. That means we here in Africa have no option, but to ignore the directional call and each and every time we stand the chance of a rebuttal or worse a NIL log entry.

I managed to work 9M4SLL Spratley Island a few moments ago on 20m CW, the operator was extremely slick and was working and using the directional call system. He did respond to me during “NA”, but I distinctly got the feeling I was on thin ice……

I would like to know from others what we are to do. Do we disobey the directional call or do we call regardless?

I see CY9M Saint Paul Island has uploaded their logs to LoTW. That is a shining example of how it should be done. Because of this I have already made a small financial donation. I do not believe the QSL system should be used to extort funds.

73, Pierre ZS6A