[TowerTalk] TH6DXX Problem?

[Mike Sims]

Hello TowerTalkians,

The TH6DXX problem is too much reflected power (100 w reflected for 1000
watts indicated forward) on 15 meters when amplifier power out is above
300/400 watts.  At lower power, the reflected is well below a 2 to 1 SWR
situation.  The reflected power on twenty and ten meters looks okay.  Has
anyone had a similar situation with a TH6DXX and what did you do to solve
it?  What should I look for in checking out the ant.?  

The ant. was purchased used, but all the parts were removed, cleaned and new
hardware installed with Nolox used on all the overlapping aluminum joints.
The traps weren't disassembled and inspected.  The balun is a new 5 Kw Radio
Works Yagi balun.

The ant. had a high reflected power on 15 meters when it was installed in
June.  However, the next time it was tried on 15 meters, the reflected power
was acceptable - 40 watts for 1200 watts forward.  Two days later the ant.
was used on 15 meters and the reflected power was back up to 100 reflected
for 1000 watts forward indicated and has been that way since then.  

If the 15 meter traps have to be inspected, what's a good method of
disassembling the traps?  The driven elements can be reached and removed
without removing the ant. from the tower.

Lot of questions, but the real important question is "what is the 15 meter
problem at power levels above 300 watts?

Appreciate all the past help with ant./tower questions.  Thanks in advance
for all the help this time.

        73,
        Mike, K4GMH


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