20 May 2013

Manyane Campsite Pilanesberg National Park

We had the usual great time at Manyane this past weekend where we hooked up with our friends Tony and Pat. They have a great camping trailer and we enjoyed  a number of excellent meals and a good social time there. The weather is still quite decent and mild so no problem staying warm.

From a field radio perspective, this was also a good fun learning experience. The sun spot number was reportedly over 200 which I believe is for the first time this cycle (I am not certain about that). The conditions were thus a bit different on 40meters.

I took along my prototype T-200-2 coupler (see pics below) and was able to preform extensive tests with ZS4SF, my friend Monk in Welkom. Path distance would be an  estimated 400-500Kms?  On Saturday morning I deployed both the 31 ft quarterwave counterpoise along the ground and a .05 wavelength 6ft 6 inch counterpoise. My EFHW was higher than usual. The horizontal part was about 45ft long and at a height of about 20ft. The last 20ft sloped down to my operating position. The band was a bit unstable and thus QSB did play a part. The 31ft was receiving very slightly better reports than the 6ft 6inch counterpoise but the results really were very similar. The only difference was the same as I had seen at home and in my previous park deployment and that was a significant difference in bandwidth.

I was very pleased to note that I had no problems loading up the efhw and achieving 1:1 SWR with both counterpoises. No problem at all.

On the Saturday AWA net I received lower signal reports than usual. Mostly 579 and using 5 watts. I don't know why this was? It could be that the antenna was a bit too high for NVIS work? Or the high sunspot number was affecting propagation? A station from CapeTown om Adrian did call into the net and I copied 549. However he was unable to copy me. He was able to copy the Joburg stations but down in the noise.

On Saturday afternoon I erected a 10m dipole at 25ft and was able to copy quite a few DX stations. The band was mainly open to the west and this was the direction that my dipole was deployed. I managed to work one station in India on SSB. I was running about 8 watts. He gave me a satisfying 57 report.

This was also the first time I got to try out my new efhw with the launch cord connected directly. I smoothed over the joint with plastic steel. This makes it easy for the system to slide through the branches. I need to get one more length of the smooth light cord since this slides over the branches so much easier than the thicker cord. The only negative is that if a knot is pulled tight it is much more difficult to undo the knot with the thin cord. I am not sure how to improve this factor.

I also tried out my new modular dipole system. I took only a single center connector/hub. Then I was able to change the dipole lengths accordingly by screwing the different quarterwave lengths into the chocolate strip using my leatherman knife. I found this time consuming and a pain. Give me a doublet any day!

Observations and future actions.

  1. The efhw fixed component doubler definitely works in the field without having to tweek it. Next adjust the smaller T-50-2 coupler using fixed components.
  2. The quarterwave counterpoise results in greater bandwidth than the 0.05 wavelength counterpoise, however the performance on the air is the same.
  3. An efhw deployed higher does not appear to really improve local (NVIS) communications when compared to a 10-15ft high configuration.
  4. The new fishing weight launcher is pure pleasure to use and I cannot think of any way to further optimize it. This launcher can be easily tied to any cord using a reef knot at about 3 ft length.
  5. The modular dipole system using a single hub to reduce weight is time consuming to erect. Consider using a single wire that is marked for resonance on each band and that is simply rolled onto two shuttles at each end. This system I remember was used in the old days by the Rhodesian Army Signal corp with good success although it is heavy.
  6. A coil of wire at the end of a counterpoise does not materially affect the length of the counterpoise. Uncoiling a wire to different lengths and leaving the remainder as a coil at the end makes sense.
I still don't have a good method to sucure the inverted L at the 'knee' point. This trip I tied a knot in the efhw. This came under some strain and I noticed that the pvc insulation had been slightly damaged. How can I solve this problem in future?

My Field gear for this trip. 
Click on pic to enlarge.

Top Left:
  1. ~ Quarterwave counterpoise for 40m. 31ft in length.
  2. ~ 0.06 wavelength counterpoise for 40m. Approx 6ft 6inches.
  3. Four lengths of 20meter slippery cord including the fishing weight antenna launcher.
  4. Leatherman.
  5. Microphone for the K2.
  6. Cable for connecting to the CW Paddles.
  7. CW paddles folded away. Palm Mini paddles from Morse Express.
  8. Altoids tin variable QRP coupler for EFHW antennas
  9. RG58 coax. About 20meters.
Center Left:
  1. Short coax connector  for coupler connection.
  2. Earplugs.
  3. Diploe center hub with 40m dipole connected.
  4. Quarterwave wires for 20m, 15m and 10m. Can be attached to the diplole center hub using choc strips.
  5. 12V battery cable for backup connection to car battery. (never been needed yet).
  6. A bag of different BNC and PL259 type connectors
Bottom Left:
  1. Pen.
  2. Small notebook.
  3. Box with prototype T-200-2 coupler
  4. Elecraft K2 full featured Kit Transceiver.
  5. K2 custom built carrying case.
  6. Small backpack for all the gear in this pic (except the K2)

Only in South Africa will you see cooking camp ware like this :)

Tony doing his thing. This is a serious breakfast buddy!

Prototype high power efhw coupler using a T-200-2 Toroid and 115 pf coax capacitor.

Berry, Pat and Tony alongside the camping trailer. Superb!

Pilanesberg National park. Click to enlarge.

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