Radio W4KAZ

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2009 ARRL 160m

Got a chance to work on the matching network for the inverted-L, adding in series capacitance, a choke, and balun. This gave me a good match at about 1840, and the SWR was decent from 1815 up to about 1860. The results seemed to be an improvement in the chances of being heard by most stations. That’s with just 100w. Decent results, given the low power and inefficient antenna.

Got in three really nice runs. The first was disrupted by another station sliding in. That was annoying, because the 10 minute rate was up over 100. After I moved, I settled into a nice 40 minute run that finally pooped out of its own.

There was only a limited amount of time available, so the periods from 2300 local “until” were chosen from both evenings. There seemed a whole lot less activity on Saturday evening. Logged about 3 hours and 130 Q’s Friday night but only 2 hours and 70 Q’s Saturday.

Found KH6ZM working a big pile-up on Friday night. Listened to that for a while, but I only heard him work a couple of east coast stations. The west coast and mid-west were pretty thick, so I didn’t waste time. Tuning up the band I found HI3 calling with no pile-up. Also worked a G3 and a few Caribbean stations.

The K9AY made the difference on several Q’s. The noise wasn’t bad, but There were a couple of relatively weak stations that really peaked on the K9AY but were in the noise floor and not copiable on the inverted-L. Armchair copy on the K9AY. Interesting. Many others were easier copy on the xmit antenna. Also interesting.

The matching network is another great application for a relay box, so I can have a good match at selected parts of the 160m band. With low power, the 3KV panasonic capacitors seemed up to the task, and I saw no signs of the SWR shifting when running, so I presume they are able to handle the 100w level. With several in parallel they seemed to handle the current. Given the bandwidths I am seeing, resonance points at 1815, 1840, 1865, 1900, and 1930 should serve the purpose.


  • Elecraft K2, 100w, into inverted-L and four direction K9AY rx array

The Good:

  • The matching network changes worked.
  • The inverted-L improvements seemed to help the station to be heard, but there’s no easy way to quantify that.
  • Rain shield added to cover feedpoint held up to nasty WX.

The Bad:

  • Not enough time available to operate.
  • Missed the start of the contest.

The Ugly:

  • None!


Call: W4KAZ
Class: Single Op LP
Operating Time (hrs): 5

Total: QSOs = 200 Sections = 50 Countries = 5 Total Score = 22,825

    2 comments to 2009 ARRL 160m

    • Looks like the capacitors are serving you well Keith. The 160 contest is a lot of fun. The rates can be pretty darn quick in that one. I’m hoping to get on for an extended period of time in the CQ 160 CW at the end of January.



      • Yeah, the match net really seems to have helped. I was surprised to be able to run stations so easily. Rooting around, I realized I’m out of cat5 for making new switch control cables, so the project to switch in capacitors to give a better match across more bandwidth is gonna languish til next year. Maybe I’ll luck out and find some surplus cat3 or cat5 at a ‘fest. I need about a hundred feet to go from the shack to the “antenna hub”[all of the antennas are centered around the sixpak]

        73 de w4kaz

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