[Icom] Strange IC-765 40 meter problem

[Matt Erickson]

Check all coax connections. The root of the problem might be that you have 
a loose or corroded element on your 40 mtr beam.
Windy days would show that the element is moving around, and has a poor 
mechanical/electrical connection. If one element tip became disconnected, 
would severely unbalance the beam (which is a balanced system), and cause a 
mismatched system, even if the element is not the driven element.

73 de Matt KK5DR

At 06:43 AM 7/28/02 -0400, you wrote:
>For brief background, I began noticing something interesting with my 
>IC-765's performance on 40 meters earlier this year.  The receive level 
>would occasionally reduce considerably and suddenly (i.e. one second the 
>band sounds normal, the next it's severely attenuated).  After hitting the 
>keyer, even briefly, everything returned to normal.  I noticed this 
>happened more in windy conditions than not, so assumed it was my 40 meter 
>beam.  Also noticed that sometimes the SWR would go up to 3:1, then back 
>to a more normal 1.4:1.
>
>Decided to replace the balun and coax on the beam.  Also checked 
>everything else out while we were up there.  All looked fine.  Came back 
>down, fired things up, had a 1.2:1 SWR.  Stations sounded fine.  Then the 
>receive problem kicked in again, and the SWR is now > 3:1!!
>
>Is it possible this is something with the 765??  Has anyone seen or heard 
>of this happening?  It's so bad that even the antenna tuner won't knock 
>the SWR down.  I don't have another rig to test it with, so now I'm 
>stumped.  But we've replaced virtually everything that can be replaced on 
>the 40 meter beam, so I'm now out of ideas.
>
>Any suggestions will be more than welcome.
>
>73, Joe KQ3F
>
>----
>Your Moderator: Dick Flanagan W6OLD, icom-owner@mailman.qth.net
>Icom FAQ: http://www.qsl.net/icom/