Mark:
Regarding the 0.5 ohms on the KT34-XA, it is desireable to have the least
amount of resistance in an antenna of this type in order to have max
current and consequently since P = I * I *R, have max power. If you look
at the tip elements of a KT34, you will see two aluminum tubes with blue
caps on them and butted together. If you trace a path from the short tube
(10 meter capacitor) you will go down an "a" strap to a3/8 " linear loading
section to a Linear Jumper Strap then to a 6 foot , 3/8" tube all the way
to the right through the capacitors to a 15 meter shorting strap to a 1/2"
alum. tube to a clamp and then to another strap and finally arrive at the
15 meter capacitor section. This should be a continuous low-resistance
path somewhere between 0.1 to 1.0 ohms. This info does not appear in the
instruction manual; however, they do say "Check for continuity across each
joint. This check will almost invariably expose the problem and we
consider it a most valuable time spent to insure trouble free operation".
By measuring between the two capacitors, you can determine the path
resistance. There are many reasons for not achieving this low resistance
condition such as: 1.loose connections 2.corrosion between metal to metal
contact points 3. A sort of hard grey substance (at the joints) which is
left over from the copper based "penetrox" (KLM's wording) paste and seems
to act as an insulator (after years of exposure). When I measured my
antenna elements I had ohmic values all over the place....240, 120,75, 20,
and 0.7(!) ohms. Thus, in order to achieve max efficiency, It is
necessary to take the elements apart and clean them up once more to a
bright shiny surface and then to re-apply noalox or penetrox or whatever.
KLM is now using a different kind of paste then I was supplied with. My
tube of noalox does say that it prevents corrosion and enhances continutiy
!!! So, anyway, I'll use it and keep fingers crossed.
I could go on a lot more but it's time to go design some cars. Let me know
if I can be of further help.
73,
Bill Haselmire WX8S
wbh3@chrysler.com
MREISING@aol.com on 10/29/98 11:23:32 PM
To: rikik@inter.net.il, WBH3@chrysler.com
cc: k6_ll@juno.com, towertalk@contesting.com
Subject: Re: [TowerTalk] Re: KT34XA refurb/0.5 ohms
Apparantly I missed the first part of this thread. I recently acquired a
KT34XA from an SK and it is awaiting the installation of my tower. What is
the reference to 0.5 ohms? I might as well refurbish the antenna while it
is
apart. Thanks for any info provided.
73 de Mark, WB9BVV
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