Saturday, June 11, 2011

6m digital DX

Conditions were again great on 6 metres yesterday afternoon and evening, with the Sporadic E favouring Scandinavia and the Baltic countries. After making a few contacts on SSB - it's always gratifying when using an attic dipole to have stations come right back to your call and give you a 59 report - I was tuning up the band and heard the unmistakable sound of PSK31 activity.

I worked LA8OKA and OH2NAF using PSK31 and SM7OYP using PSK63. I thought these may have been my first PSK contacts on 6m but my log tells me I worked Spain using the digimode during June last year.

Signals were strong and steady and most people were using their regular macros and brag files and exchanging greetings rather than sending quick report and locator overs as you might expect for sporadic propagation.

Some bloggers have been advocating using the weak signal digital modes like WSPR or JT65A on 6m but when propagation is this strong I'd rather use a digital mode that allows me to have a proper QSO and exchange names and other details with the stations I'm working.

8 comments:

Paul PC4T said...

Hi Julian, I think JT65A will better perform than PSK31. Only activity is too low, most of the JT65A users gather around on 14076. So best alternative for 6 meter is PSK. What frequency are you using? 50.250? 73 Paul

Julian said...

I'm not sure JT65A is appropriate because signals are anything but weak. The contacts I made were around 50.250.

PE4BAS, Bas said...

JT65A could be interesting with multihop ES for instance to the USA. But with the strong european ES I guess PSK is one of the best modes to get digital. I did work some 6m PSK laast year as well. WSPR activity on 6m today was low, only been received in Scotland. 73, Bas

Paul PC4T said...

Hi Julian, lower your power and you will become weak. ;-)

And Bas will use AM modulation instead of SSB when Es is strong?

I don't understand his argumentation. I do hear enough weak signals on 6 meter. Not only strong.

Anyway...

Julian said...

Sporadic-E propagation is only here for a short time, I think to make the most of it you should try to accomplish contacts in a short time and JT65A is too slow. If signals are weak it means the Es clouds are moving away or dissipating - another reason to complete the contact quickly. But I am not one of those people who believes in using low power for the sake of it. The point of QRP for me is so you can use simple or battery powered equipment. If your radio can do 100W and it gets the contact made quicker or better, why not use it?

Paul PC4T said...

How slow is slow? A normal First round with PSK31 takes 28 seconds. A JT65A takes 46 sec, a difference of 18 seconds. We are not talking about meteor trails, which will last for a few seconds. Es clouds normally, during the summer season, stays a lot longer. Much longer than 18 seconds. A ISCAT or JT6M CQ takes 28 seconds for meteor scatter. From experiments is proven that PSK31 is not that sensitive and accurate in decoding as JT65A. QRP is not a religion for me, and I am not a purist. For DX-ing I use sometimes 40 watts with digital modes, if necessary. And occasionally I use 100 watt SSB on 6 meter. Hi. Everybody should use the mode he likes to use. Useful or not, but I hope that more radio amateurs will use JT65A on 6 meters just for fun and experiments and not only gathering around 14076 KHz. 73 Paul

Martin said...

Hi Julian, it was a pleasure to work you on Friday evening!
Too bad I didn't have any time for chatting; I was quite busy working the pile-up.
I agree with you regarding the long macros. I actually did the same mistake myself, starting with too long macros because I didn't had any macros suitable for this kind of operation. I later changed to my contest macros and made them suitable for this kind of operation, and later on I changed to PSK-63 to speed up things even more.
It was very fun to have a pile-up from LA. I have only had a pile-up from LA on a couple of occasions before and was taken by surprise!
When I worked HF from OX and HF and 50 MHz from JW I expected that it might be a pile-up, but I didn't expected that on Friday evening when I sat down in front of the transceiver just to check if there was something "on the band". It was kind of a "learn to drive while driving" experience to me.
Next time I will be better prepared!
When the conditions started to get lower, PSK-31 was too slow to use on sporadic E. PSK-63 worked better when the rapid fading occurred. PSK-125 would probably have worked even better. With condition like it was on Friday evening with strong signals and rapid fading, I suggest using a fast mode and short macros.
Since PSK-63 and PSK-125 operation is familiar to more people than ISCAT, JT65A and JT6M, PSK-63 and PSK-125 will probably make more QSO’s giving more people a chance to work the DX when condition are like they were on Friday evening.

Paul PC4T said...

Hi Martin, indeed would be PSK63 and PSK-125 a good choice for Es propagation. I wonder why hams are using SSB and CW most of the time on 6 meter. There are enough PSK amateurs, why not on 6 meter. I never heard any PSK lately on 6 meter. Why not? 73 Paul