Thursday, 5 March 2015

Increase activity with JT9

Since eQSL has now 2 certificates you can get with JT9 digimode I hope activity will increase because of this. You can get those certificates when you got 100 DXCC JT9 QSO confirmed by eQSL (eDX100) and 50 USA states JT9 QSO confirmed by eQSL (eWAS). I think the ePFX300 award is to follow. I'm curious how many operators have worked 100 DXCC on JT9, I don't think there are already 100 DXCC active with JT9 actually so that will be a hard one to get. Overall these certificates are a great way to increase activity with JT9 as many do collect awards and want to have a goal to accomplish. I tried to make some QSOs in JT9 mode last evening but still find activity low compared with JT65.

Although not everyone is a certificate hunter it is nice to have a goal if you need one. To obtain the JT9 certificates on eQSL I still have a long way to go.

Some of the best designed eQSLs received are from digital mode operators and JT9 especially.

Still I am suprised there are not many more that use JT9 digimode but stick at JT65. I think it has to do with the fact that only WSJT-X is capable of JT9 at the moment and JT65 can be done by a lot of other programs.

Monday, 2 March 2015

CQWW 160m SSB contest last weekend

It has been 2007 when I last participate in this contest. I then was the only participant on SSB from the Netherlands and of course got first place! Actually the time this contest is on (best at night) is a good thing when you haven't got much radio time at daylight. I mainly participate this time to work HV0A from the Vatican as a new band one. I managed to work HV0A after a hour or so. I stopped at 100 QSOs sunday evening. Now I read the rules afterwards (stupid me!) and it is not allowed for single operator low power to use any assistance. And of course I did, and so did many others according to the "logs received" page of the CQ 160 contest .

So that leaves me with a choice of high power assisted only. That is probabely why they put me in multi-op section in 2007. Another handicap at least for dutch operators was occurring as well to me, we are not allowed to transmit above 1880 KHz though other countries can operate till 2000KHz. So dutch operators can never seriously take part in the 160m SSB contest as they just miss too many multipliers and QSOs. I heard HK1T (Colombia) with S9 sunday night but it was above 1880 KHz so it was not possible to try and make a QSO. Anyway it suprised me that I managed to create a small pile-up and even got spotted on a DX cluster. I switched between the loop fed as endfed and the vertical, although I had the idea both antennas produced a identical signal. In the end I worked 30 different DXCC. It has been a long time I made so many QSOs on 160m in one weekend and it was certainly fun!

Saturday, 28 February 2015

Interesting loop tests with 1:1 baluns on 160m

After reading some advice on a radioamateur forum regarding the use of a "short" loop like I have on 160m I tried a 1:1 balun between the ladderline and tuner instead of the built in 1:4 balun. I can't tune my loop on 160m unfortenately, it could be the Palstar AT1KM differential T-tuner has not enough capacity. The story goes that the R of the loop is lower as 50 Ohm and if you use a 1:4 balun R would be even 4 times less which is the cause of difficult to no tune. Another story goes that a 1:1 balun between the transceiver and the loop should supress interference, noise or whatever. Time to test the truth!

The Palstar is able to act as a endfed tuner by removing a bridge to the 1:4 balun inside. I tested it with only one end of the loop connected it didn't make much difference against my short vertical fed by coax and a autotuner at the feedpoint although the noise was 1 S-unit stronger. I use the vertical as reference for the tests I made.

I first connected a Diamond BU-50 1:1 balun to the ladderline and tuner. It immidiatly occured to me that tuning on 160m and 80m was easy but 40-10 got difficult. I then made a transmission on JT65 on 160m and was received but not with that good signals. I tuned in on some SSB stations from Italy and switched over to my vertical. The difference was astonishing, the vertical receive was at least 4 S-units better. And I was able to hear other stations that could not be heard on the loop. The balun is ok, nothing wrong with it. So this was not a great succes, the only advantage was that I could tune the loop!

Now, I don't have a lot of noise on 160m. But with the pre-amp of the Icom-706 on I can produce a S6 noise signal. Time to test the noise reducing story. This time I used a homemade balun with 50 Ohm semi rigid coax cable on a 4C65 ferrit core. You can see it on the picture. I connected it between the tuner and the radio. To keep a long story short, I cannot hear or see any difference! The noise was S6 with or without the balun. I then switched to the loop acting as a endfed and have S7 noise, again tested it with and without the balun and it did not make any difference.

What is my conclusion? Or what did I learn? Well, I can get the loop working on 160m with the tuner and a 1:1 balun but not with a 1:4 balun. Strange as others with similair loops can, though I doubt the effectivity of those antennas. My too short vertical is defenitely doing a lot better. Besides that, standard antenna theory never works here, for some reason it is always different from what others experience. I learned that when building a endfed and several other antennas. What I learned is that the advice given by others is not always working, actually I knew that already.

I have a great time in the CQ 160m SSB right now. Just worked HV0A from the Vatican with.....the loop fed as a endfed.