Greetings Gang;
Lee wrote:
<<The TA-33 is acting funny....snip.. On Ten meters it is OK. SWR is fine
and it shows a curve that is "normal" Same thing on Fifteen meters. When I
get to 20 meters, well the SWR is 2.7 to one all across the band. snip>>
Last year, I helped a friend refurbish a TA-33 that he purchased used. It
had similar problems. SWR wasn't too bad on 10 & 15, but on 20 it was 2:1,
but not quite as bad as yours.
Our fix:
1) Dissasemble each joint, clean with scotchbrite, and apply Penetrox (or
No-Alox) and reassemble. This improved the swr only slightly.
<head scratching session, followed by cold drinks>
2) Dissasemble each trap assembly, loosen and retighten each screw that
terminates the coil for wire ends. These are aluminum screws on aluminum
wire. You know the story there over time. Refreshing the screw contact
breaks through the oxide. We should have spot applied penetrox here but we
didn't. We also noticed that 2 of the coil forms were cracked, causing minor
distortion in the coils. We ignored these and reassembled.
3) The SWR was remarkably improved, the beam is in service now, and Tony is
very happy with it.
Hope this helps you.
--...MARK_N1LO...--
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