Tuesday, December 16, 2008

ARRL 10 Metre Contest...13th/14th December 2008

Considering that this is the only band I am really currently active on, I was on during the 2 days of this ARRL contest to see what would pop up. At this stage of the solar cycle, the solar flux level (~70) is way too low to support direct F2 propogation from this far North in Europe (52 deg N). However, some Winter time Sporadic-E came to the rescue and there were short weak openings to F and EA from here. It's amazing that when all that activity is concentrated on one band, every propogation path becomes obvious and is spotted on the DX-Cluster. Most of the signals were weak although one French station did peak at 599+10dB. However overall, most signals were weak and CW was really the only way of working most stations.
Some observations...
1) In total over the 2 days, I worked 7 EA stations, 3 F stations and 1 S5 station. There might have been some openings to Germany as well but either I was missing or it was too weak for me to hear. The band opened up for a while to LA as well with the beacon LA4TEN in JO28 making an appearance for a while. No LA stations were heard though. In terms of DX, V51AS was heard although very weakly.

As you see from the map, the orange areas represent was worked....all Sporadic-E and about 1,000 to 1,800 kms distance. The V51 station was probably a combination of both Sporadic-E and F2 layer propogation. Sporadic-E from here (IO51) to Spain and from there probably by F2 to V51.

2) This year, the contest coincided with the peak of the Geminids meteor shower. I heard plenty of pings from beacons over the weekend and no doubt, a good few contacts made by stations in the contest may have been due to meteor scatter whether they realised it or not!

3) On a personal level, several years off the radio didn't do much for my CW!.........Oooo........very rusty ;o)

4) After I worked the S5 station, I heard Robbie, EI2IP working him. Later that night I noticed that Robbie had put up the following spot on the DX Cluster

EI2IP-@ 28000.0 EI7GL John ur cw tone is not so clear! 1215 14 Dec

So, I turned on a 2nd reciever with no antenna attached and listened to my signal on 5 watts....

di...di...di...dah.....di...di...di...dah........sounds ok........Turned up the power to 50 watts.....

ch...ch...ch...chirp.....ch...ch...ch...chirp.......Oooooo......Not so good!! :o(

It reminded me of when back in the days when the Soviet Union existed and a lot of the stations there were using home made rigs and plenty would have a chirp on cw.

How to fix my problem??? I thought at first it might be too much RF in the shack. I know I cause interference to the loudspeakers of the PC in the shack so I thought that might have something to do with it. Perhaps RF was getting into the power supply or somewhere else.

Connected up my 20 year old home brew 100 watt dummy load and tried it...

ch...ch...ch...chirp.....mmm.....no joy. Then I looked at the power supply. It's a variable power supply going from 0V to 20V with a small analogue meter to show the o/p voltage and current. Looked a bit low.......mmm......checked it with a digital volt meter.....~11 volts!

Turned it up to 13.5 volts and tried again...

di...di...di...dah...success!!...........It turned out that I must have knocked the voltage dial at some stage and the Kenwood transciever didn't like transmitting with a low voltage supply. Not only that but my max power out now has increased from 80 watts to the full 100 watts.

All from a simple spot on the cluster!....Thanks Robbie :o)

5) .....and on a final note, I found myself listening nearly all the time on the CW part of 10 metres for the duration of the contest. I listened to the SSB section for a while, heard some weak signals but to be honest, I never felt inclined to open the drawer, take the microphone out, plug it in to the rig and call someone. I wonder if I was operating just SSB only, would I just get bored of the whole radio thing again???


Ei2iP said...

Happy to help John.

My best DX over the weekend on 28Mhz CW was;

ZS1EL & V51AS.

Also worked MI0LLL maybe tropo on SSB.



John Desmond, EI7GL said...

Interesting about the MI0LLL station. Sometimes it can be hard to call what the exact type of propogation was. I assume he was weak. If you were beaming North at the time, I'd guess tropo. If you were beaming South/South-East, it could still be tropo or it might be Sporadic-E back scatter.
If you look at the link above, he has a fine setup there for contesting.

Ei2iP said...

I think at the time I was beaming SE, peaked 57 a few times..as you said hard to determine what exact propagation, as I heard him several times. He was working DL's at the time so maybe some form of side scatter...
I think next dry day I will try to get the 50MHz yagi on mast, but I need to change the rotator pole first!