It would now appear that you have narrowed the problem quite nicely. The
only thing common to all of the permutations you have described is the
antenna system. From the connector at the shack to the antenna. It would
seem there is a corroded joint somewhere. I would suggest the bracket and
halving technique from the shack connector to the antenna. Only a guess, but
the aluminium joints in the beams would be my first guess. I suppose it
could be in any of the antennas, however. It would seem possibe to have
rectification almost anywhere where there is a strong RF field.
gud luk es 73,
Sam, W5LU
>From: "David Robbins" <k1ttt@arrl.net>
>To: "'Amps'" <amps@contesting.com>
>Subject: RE: [Amps] al-1500 parasitic?? or some other problem?
To: <amps@contesting.com>
>Date: Tue, 14 May 2002 22:30:11 -0000
>
>At this point nothing is a stupid question, I am definitely confused.
>
>I am using other radios in the shack to measure it. It was first
>noticed for the bad clicks on 15m. The 15m station has an ft-1000mp
>with antennas on a separate tower about 300' away from the 20m tower.
>To eliminate the rx as a problem I also hear it on a ts-680 that is
>connected to a 6m antenna on yet another tower.
>
>Add another twist or two...
>
>There is also a sub-harmonic being generated at exactly 1/2 the tx
>frequency. It comes and goes exactly in sync with the 1.5x 'harmonic'.
>
>Now the real kicker! I swapped the al-1500 out for an hf-2500, and the
>'harmonics' are still there. And they respond to the tune control on
>the hf-2500 exactly the same as on the al-1500.... so now I am down to
>the 'some other problem'... still related to amps, but apparently not
>specifically the al-1500. This makes the problem much more important to
>find and fix as the last resort plan was to move the al-1500 to 10m, but
>obviously this is not going to fix the problem now.
>
>
_________________________________________________________________
MSN Photos is the easiest way to share and print your photos:
http://photos.msn.com/support/worldwide.aspx
|