[TowerTalk] KLM Vertical

[ABowenN4OO]

At 06:31 AM 10/3/2000 -0700, W7ZR wrote:

>Anyone know of a KLM 160-80 vertical?  A friend told me KLM made such an
>antenna.  Any out there for sale?  Any information from past or current users?
=====================
KLM made an SSV 80-40-15 which could be base loaded for 160. It consisted 
of a tripod of 2" OD tubing which extended to 30 ft. Additional tubing 
extended from one leg going through a series of size reductions to the last 
piece which was 3/8" diameter and was adjustable. Overall height was around 
68 feet.

The other 2 legs were insulated from the "long" leg at the center and top 
and were fed in parallel on 40 and 15. Tuning on 40 was very broad, 
covering about 6.5 to 8 mhz according to the spec sheet.

KLM offered a coil of 3" dia., #10, 4 TPI for base loading on 160. The 
antenna would not be very efficient on 160 unless an extensive ground 
system was installed. Even then, the efficiency would be down 3-6 db 
compared to a full size vertical (maybe more), depending on the length and 
quantity of radials.

I do not think that KLM produces this antenna now.

I have one of these antennas, obtained in a swap a few years ago. I changed 
the tubing schedule of the top section to stiffen it up. I also added 3 guy 
lines at the 45 ft level to minimize the sway of the upper element. In a 
stiff breeze, the original element would bend almost horizontal.

I used mine on 80M, but never attempted 160 since I already have a shunt 
fed tower with 60 radials. For the KLM, I put down 60, 65 ft radials. The 
feed impedance was fairly low, so an L network matched it to 50 ohms. I 
worked everything I could hear with the antenna.

A recent lightning hit reduced the L network to small pieces of #12 wire 
and chunks of an old style, large mica capacitor. In addition, the 
lightning current welded the male/female connectors together at the antenna 
and also at the RCS8V remote switching relay. The PC board in the relay box 
was about 60 percent destroyed and contacts on 2 relays were welded 
together. The antenna had a burn spot about 18" down from the tip but there 
was no other damage. The next iteration of this antenna will have a spark 
gap device connected to the ground system.

INK N4OO



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