In a message dated 11/3/01 5:35:51 AM Pacific Standard Time, realex@flash.net
writes:<<
I recently disassembled an old Hygain DB1015 that had elements thoroughly
stuck together by pouring some hydrogen peroxide over the joints in
question. It
will loosen or break up the oxidation holding the joints together. Repeat
as needed
73, Bob, W5AH
-----Original Message-----
I picked up a Telrex 20M646 which I am working on adjusting the element
lengths. Many of the elements are tight and will not budge. I have tried a
number of things to get the element end loose with no success. Has anyone
else experienced the same problem and found a solution?
>>
Heating with a BurnsOmatic torch can help also. Laying the tubing on
concrete and tapping with a hammer will help break things loose and if
pounded enough will actually enlarge the diameter. I've bolted a plug into
one end and used long rods to tap it out. One bean had been together for
about 40 years I got from a friend. I took a 3' 1/2" steel rod and slipped
it in one end of the tubing. Holding it on the edge of the roof I tilted it
vertical and let the rod fall inside as a jack hammer 33' to an end plug held
by 2 1/4" bolts. I even had to jerk the tubing up at impact. After about 50
or more jack hammers I got the elements apart without damage. The aluminum
oxide had grown .015" thick on the telescoping joint creating a fair
compression joint. The ohmmeter test showed in was a capacitor. This was an
extreme case but many yagis have a capacitive joints in time. Quads have one
permanently soldered joint and no deterioration of performance.
When someone offers you an old beam--run as fast as you can-the other way.
k7gco.
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