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KT34 Antenna

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by WA4OTD, Aug 11, 2012.

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  1. WA4OTD

    WA4OTD XML Subscriber QRZ Page

    I will soon be a KT34 expert I think. Friend of local SK was able to pass on to me about 16 elements of KT34 antennas and one 3 inch boom. I have been downloading all manuals and instructions I can fidn. I hope to put together a 3 element tribander for my attic and one to use for portable operation or install at my mom's house in TN. Generally people that have this antenna seem to love it once it is together.

    Comments on the KT34 antenna?

    I didn't get a balun so will have to make one or buy a balun.

    Attached Files:

  2. WA6MHZ

    WA6MHZ Subscriber QRZ Page

    I have one up and the remaints of a 2nd one in the driveway. One element fell off the one in the air and I need a bucket truck to put it back on. So, be sure when U mount it, U put in the hold-it screw into the Hose clamp on the boom. If U get a few bucks up, I would recommend doing the M2 Mod to the KT34, which makes it much more sturdy and does away with all the plastic insulators on the elements which tend to break up and cause problems. The M2 Kit isn't easy though. It took me a couple months of wirebrushing each element and then some have to be cut and modified to use in the new kit. Looks like U have more than one beam there. If U do keep it stock, make sure you score a manual to it as all element lengths are very critical and difficult. Probably the most intricate antenna ever made.
    But they work well once up in the air. Just wish I could get my 4th element back on the boom here.
  3. K9XR

    K9XR Ham Member QRZ Page

    I had one of the first KT-34s in 1979. I had it up at 96 feet for about 13 years. I was never real happy with the SWR curve as it was in a pretty flat line but never got much below 1.5:1 on any band. I replaced 4 Element mono-banders on 15 and 20 and 5 el on 10 with the KT-34. Although I never was able to compare the antennas side-by-side it "felt good" to me. It was up about 20 feet higher than the 10 and 15 meter antennas and at the same height as the 20 meter antenna so that might have made a little difference on longer paths. I can count the number of times on one hand that I thought the difference in antennas was significant. I have used just about every tri-bander ever made and I really think this was as good if not better than any of them including the bigger ones like the TH-6 and the TA-36. I am sure that none of the smaller tri-banders came close to it.

    About the only problem I had was with the boom insulators cracking. It was a very common on the earlier antennas but was corrected on the later ones.

    If I remember right the Balun was a 4:1 and it seemed very small compared to Hy-Gain and even the W2AU Baluns, but it seemed to do the job.

    With the 16 ft. Boom and the linear loaded elements the turning radius probably isn't much worse than a TA-33 or TH-3.
  4. K7MH

    K7MH Ham Member QRZ Page

    I used to have one. There are about two billion parts in that beam!! Measurements need to be accurate. The only band I had trouble with getting a good SWR was 15 for some reason but it worked pretty well otherwise.
  5. WA4OTD

    WA4OTD XML Subscriber QRZ Page

    Thanks for the comments, this is an interesting antenna. Many of the elements are just 1/2 loosened up and folded over so I hope I can get those together quickly. Everyone talks about how critical the measurements are, which isn't my strong point so hope it works out.
  6. W9GB

    W9GB Ham Member QRZ Page


    You have some decisions to make before you start restoration of this KT-34 antenna.
    Which restoration path do you desire to take?

    My personal preference, IF you want to keep the Antenna, Purchase the M2 Upgrade Kit,
    land rebuild he entire antenna, cleaning aluminum tubing and joints as you go.

    I have a personal preference with antennas, get it right the FIRST time, saves time and $$.

    KLM KT-34 Bandpass assembly manual, circa May 2, 1980

    KLM KT-34A Bandpass Tribander assembly manual, circa October 24, 1983

    M2 KT-34(A) to M2 KT-34M2 UPGRADE KIT, Current M2 offering for KLM owners
    The M2 KT34(A)-KT34M2 UPGRADE KIT provides all the parts to bring up your old KT34(A) to current ‘34M2 specifications and keep it that way.
    Over the years it has become evident (to the original designers) that the original sheet metal straps loosen with time and the connections become intermittent and / or lossy. The new close tolerance, CNC machined shorting BARS produce solid, low loss connections for years. The machined bars also add mechanical stiffness to the element.
    In addition, all new hardware has been supplied as well as new UV stabilized Capacitor Caps and tubes needed for the new ‘T‘ match. TO KT34M2 UPGRADE KIT.pdf

    4402 N. Selland Av.
    Fresno, CA 93722
    559-432 8873
    fax 559 432 3059
    Email to:
    Last edited: Aug 12, 2012
  7. WA4OTD

    WA4OTD XML Subscriber QRZ Page

    Thanks very much for the info!

  8. WA6MHZ

    WA6MHZ Subscriber QRZ Page

    What makes a big difference in the rebuild is to WIRE WHEEL BRUSH the elements. I went overboard and completely brushed each and every element, and each inch of every element down to bare metal, removing decades of corrosion. This is a very tiring and messy process, but well worth it. I bought a Grinder at harbor Freight and replaced one of the wheels with a wire brush. The thing spins at a way high speed, and can rip the element right out of your hand if you aren't careful. But the shine it leaves is like none other, and you can be ASSURED of having a perfect joint for metal attachment when the time comes. Yes, it took me several MONTHS to do it. I would come into work and sit outside weekends, wirebrushing away.

    In the M2 Kit, I found a few things weren't quite right. Some of the antenna elements wind up too short, and I had to find some correct size tubing to replace the elements with. Also, there were some fibreglass insulating inserts that were not as described and I had to order new ones from the factory. But I got my M2 rebuild kit 2nd hand for $25 from a Silent Key sale, along with a whole bunch more elements.

    My original KT-34 was up on a Pushup mast and a big wind blew it over smashing it into the roof. So I had to score a 2nd KT-34 to get the wasted elements replaced. I can't remember when I ever worked so hard on ONE antenna!!!! The elements, as modified, were built here on the WORKPLACE floor, and measured out to perfection.

    Getting it up proved to be a nightmare, and many attempts were fruitless, including trying to PULL UP the tower with a big rope lashed around the Town Car! That was a mess! Only when some great guys came all the way from Hemet to help out were we able to Walk it up, Mt Surabachi Style, did the antenna finally get into the air. But, alas, it was a shortlived success when the front director fell off due to not having checked that the hose clamp was tight and secure.

    I Still have worked lotsa DX on it without the director, but it is very compromised. No chance the antenna can be brought down, other than just cutting the guys and letting it fall over, smashing itself into smithereens. So, months have turned into YEARS of trying to find a BUCKET TRUCK to get the element back on. THis has been so agonizing, especially over the 7O6T debacle. While everyone else in town heard them 5x9, I could just BARELY tell they were in there because of the missing element. I even inquired into renting a lift, but they quoted me well over $500 for a few minutes work. I tried to get a Power Company bucket truck to help me out, but they refused as it was against company regulations.

    So, here i sit with a KT-33, still working DX, but just barely.
  9. WA4OTD

    WA4OTD XML Subscriber QRZ Page

    Sorry to hear that Pat. Maybe some tree service has a bucket truck that would reach you antenna and do it for reasonable price. I think I could spend a long time with a wire bush on my elements.

    I hope I can get 2 elements in my attic and maybe 3 elements. I'm sure the lack of a balun has my present single element tri-bander not performing so well. My first task is to wind a few 50-200 ohm baluns. they are a beautiful antenna. The more I study them the more I'm impressed with them.

    Attached Files:

  10. KH2G

    KH2G Ham Member QRZ Page

    I really liked mine, enough to send it to various islands with me. I t was finally laid to rest on Guam when I didn't get a chance to take it down soon enough and a 200+ MPH typhoon hitting Guam did the job for me. The comments regarding making sure the contact points are clean and accurate are true and will have a large effect on the performance.
    I believe, if you take your time and add some antioxidant at each joint during assy, you will have no regrets and find you won't need high power for that DX out there.
    73, Dick
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