Okay fellows, thanks for all the ideas. I need to let everyone know it was
necessary to round up a wench to finally get these two pieces of aluminum
apart! (And a mighty find wench she was, I must say!)
On the other side of the element, this joint slipped apart real easy. (This is
the side that points True North.) This afternoon I took the antenna down to
work on it on the ground. I ended up sacrificing the smaller diameter tube even
after soaking the joint overnight with LPS and downing the Coke as instructed.
Sears was back ordered on the pipe wrench and I'm not allowed to play with
matches so heating the outer tube was not an option.
Once I got them separated, I saw there WAS oxigard (or whatever the grey stuff
is called) in this joint, but part of it had hardened like concrete. Other
areas were still "wet". I ended up strapping the "thick" end of the element to
my Ford tractor 3-point hitch using hose clamps. I was necessary to grip the
smaller tube with vise grips... thus the sacrifice. When I spun the smaller
tube I asked the wench to pull on the loose end. In about 2 minutes we had it
apart. But you wouldn't believe how HOT that tubing got from the friction!
In any case, I salvaged a replacement piece of tubing from an old yagi. (Never
throw anything away!) I cleaned everything up and put it back together. I ran
some VSWR sweeps with this element sitting on a step ladder. Right now it
resonates about 6600 KHz. When I raise it back to the 65 foot level this will
move up the band. Just how much I'll report later this weekend. (BTW, when I
lay it on the ground, it resonates at 4400 KHz, so 5 feet makes a big
difference!)
The first time I put this element up (to chase 3Y0X in February), I
under-estimated how much it would shift up in frequency. So the resonance ended
up about 7500 KHz. (I think it moved up over a half meg!)
That's what started this whole fiasco in the first place... my desire to
lengthen it and get it to resonant in the 40m band! I'm starting with 75 ft 5
in total length this time. If I did my math correct, that should put it on 7150
KHz.
Just why this dipole needs to be so much longer than formula escapes me! (I am
taking my measurements at the feedpoint, without coax.)
73 de Bob - K0RC
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