21 February 2013

ARLR Inter. DX Contest CW

Date Feb 16-17 March 2013. From 0000UTC Saturday - 2359 Sunday.

I participated in this interesting contest. The contest aim is to contact as many W/VE stations as possible. It is aimed at encouraging an understanding of DX propagation on the part of W/VE operators. 

I set up my field station at the Krugersdorp game reserve day picnic area. This is an excellent spot for radio. and there was no local noise on the band. There are many sky hooks in the form of very large eucalyptus trees and a lot of wide open spaces. The day entrance fee is R30 (I think per person?). The gate is open from 7am - 6pm local during summer, however I was told that you can depart the area anytime up to 10pm. I am not sure that the security is adequate after dark, but I did notice a number of security guards around the gate area. There are many braai areas and plenty of shade. The ground slopes up slightly towards the west which probably reduces the signals in that direction? The ground is soft and with few rocks, making it easy to hammer in pegs for guying masts etc. On the slight down side there are 4 lapa's there. On saturday there was a big and noisy party going on in one of the lapa's. On sunday there was more loud music coming from a group of picnickers. The area is also near the main road and thus there is a constant sound of traffic in the distance. All in all, I feel this is an excellent site. There is easily enough room to set up multiple antennas for experimental and comparative purposes.

I ran my Elecraft K2 at 5 watts QRP and operated on 15m and 10m of which I succeeded only in making  QSO's on 10m.  My key is a mini Palm which is designed for field operations. I used the internal battery in my K2 for the entire operation. My Antenna system was an inverted V center fed doublet on 15m. The apex was up in a tree about 10 meters and the wire length was about 40 meters long. This was center fed with a 300 ohm ladder line which did not quite reach the operating position. So I lengthened it with a piece of 450 ohm ladder line. This was tuned by an ancient ZW1 balanced tuner. On 10 meters I used a prototype moxon beam which I had fashioned out of some pieces of 20 mm pvc pipe, 0.5mm bare wire and a piece of plywood which I used as the hub. I attached a 1.5 meter piece of doweling to the top of my new ZS6TJS mast with two hose clips. The moxon can then be rotated using the armstrong method (see pics). See my separate write up for more details of this. 

On Saturday I was QRV at 12:30UTC. Setup time was about  50 minutes due to my unfamiliarity with the new mast set up procedure. I operated until 15:45UTC when it started to get dark and I had to leave the site. A total of 3.25 hours. I found that the 15m band was opened and that there was a huge amount of QRM from Europe. There was no way that the W/VE stations were going to hear my QRP signal. I moved to 10m which had much less QRM than 15m. On 10m I was able to get the attention of the big gun stations. I really appreciated their patience in pulling my signal out of the noise. Most of the stations asked for a repeat. I think this was due to a combination of weak signal and my difficult call sign. I noted that they generally copied ZS6R.. but had trouble figuring out the S and H hi hi. I did find that by QRS'ing down to about 19wpm that I scored a better non-repeat rate. I felt that many of the stations had multiple 10m antennas pointing in different directions since I did not notice any of them rotating their beams in my direction. Well put it this way, I did not notice their signal levels increase. These operators are very patient. I feel bad for them many times when they have to spend precious minutes digging out my weak QRP signal. But never once did an operator abandon the attempt and there was satisfaction expressed in the form of vy fb once they had copied and I sent QSL! I also noticed that a small tweek of my antenna to beam more accurately in their direction often resulted in them copying me. Next time I will take better azimuth bearing information to the field. The following stations were in my log for Saturday. K3OO (PA), K1LZ (MA), K3LR (PA), NY4A (NC), K1RX (NH), W3EP (CT), KE9I (IN), N4OX (FL), VE9AA (NB), K5RX (TX), N8AA (OH) gave me an honest 579, WB9Z (IL), W2FU (NY). When I went QRT the band was still opened and the signals were coming up as the sun set.

On Sunday I was QRV from the same site at 14:00UTC. This time I was a bit further up the slope and I only set up the moxon for 10m. I did not check out any of the other bands. I felt that the signals were stronger. However I noted that I had already worked many of the stronger signals. This time I stayed later and was QRT by 16:30UTC having operated for 2.5hours. I really noticed the signal strengths coming up as it got darker. There was much more QRM from Europe. Not sure if this was because they had exhausted 15m or if the band condx were better? The following stations were in my log for Sunday. K1ZZ (CT), N1UR (VT), K1WHS (ME), K8GL (MI), K4RO (TN), VE3JM (ON), VE3UTJ (ON), K3AJ (MD). 

In total I worked 21 stations over a period of 5.75 hours on 10 meters. The moxon performed excellently. However I wonder if a vertical might be more suitable for field DX purposes on the 10m band? It certainly would be easier to set up. The moxon has excellent F/B ratio but not much forward gain. However the problem for QRP is not so much eliminating QRM (since it is easy to copy the big guns) but more an issue of forward gain (IMHO). In a low noise field environment a vertical may perform better. It would be interesting to do some comparisons.

1 comment:

  1. Dick,

    Congratulations for getting your blog up and running.

    IMHO You certainly did very well during the ARRL DX CW contest with QRP.

    It will be interesting to see if the vertical antenna could outperform the Moxon antenna. It sure will be easier to erect.

    73, Pierre ZS6A