[TowerTalk] TH7 puzzle

[Steve Lawrence]

SUMMARY response:

Puzzle: Intermittent Hi SWR when barefoot and down to QRP levels on a  
TH7 but only on 20m. Clears when hit with legal limit power and then  
returning to LP.
.
Signal path: rig-amp-pwr meter-ant switch-coax-TH7 (w/BN4000 balun).

With rig connected directly to a dummy load, SWR is normal but the  
problem continues to appear when rig is connected directly to the TH7  
coax.

Others have had similar experiences narrowed down to the only 20m  
unique part of the TH7's DEs: the clamp on the element tip and / or  
the far end of the 15m trap. Cured by tightening.

Looks like a trip up the tower is called for.

TKS to: K4SAV, W4EF, N2TK, K1IR, N8CC, WA6TLA, W5AH and anyone else I  
may have left out.

73 - Steve WB6RSE