[TowerTalk] 80 m 4-square high SWR with no obvious reason why - using COMTEK ACB-80

[kq2m at kq2m.com]

Hi,

Before WPXCW one month ago, my wire 80M 4-square using the COMTEK ACB-80 
was working very well, with ~ 1500 W out and 100 w reflected at 3.5 mhz 
and ~ 1500 W out and 50 w reflected at 3.7 mhz.  The F/S and F/B wer 
excellent and about as predicted when the DX station signals were low 
angle.

Between then and now (one month) we had two violent windstorms and a few 
nasty T-storms, with gusts approaching 50 - 60 mph but tame compared to 
what it has been through in the past.  2 wire elements broke off, the 
F/B and F/S disappeared and the forward power dropped to ~ 800 w with 
350 w reflected from from 3.5 - 3.7 mhz.  That's normal and to be 
expected.

However, when I fixed the two elements today, while the F/B and F/S 
improved somewhat, the forward/reflected power did not go back to the 
usual values. That is NOT normal.

I checked each of the connectors and continuity at the bottom of each 
element and everything appeared to be fine. I checked all the phasing 
lines and they appeared normal.  All the elevated radials were in the 
air at their normal elevations.  I could not find anything wrong.  There 
was one sketchy looking connection on the  feedline to the shack and I 
made a new connection with a new Amphenol pL259, but there was - still ~ 
800 w forward 350 w reflected from 3.5 to 3.7 mhz.

I seem to remember something like this happening about 10 years ago with 
high reflected power and loss of F/B and F/S as a result of multiple 
COMTEK external relay box cold solder joints that were not obvious.  DX 
Engineering checked it out found the cold solder joints (that COMTEK did 
NOT find) and fixed them and priority shipped it back to me so that I 
would get it before CQWWCW which I did!  But the F/B and F/S was worse 
then than it is now so I am not sure that it is the same thing.

What is striking to me is that the forward power has uniformly dropped 
and the reflected power has uniformly risen across the entire band as 
though the entire array was detuned by 500 khz, suggesting something 
systemic.  I suspect that the problem is in the relay box but I can't 
figure out what may be causing this.

Has anyone experienced a similar problem with their ACB-40, ACB-80 or 
ACB-160?  Does anyone have any idea of what to do look for next?

Tnx & 73

Bob, KQ2M