Barry,
Not only short, but, as "fat" as possible!
73, Troy, W6HV
N1EU wrote:
> Thought I'd fill you all in on the final chapter of my
> little drama, in which N1EU triumphs after being
> plagued unceasingly by horrible nasty RF-induced ssb
> distortion from his Omni 6+/Centurion combo on 10, 12
> and 17m.
>
> I've had so many really helpful suggestions from many
> of the TT reflector gang all along the way - many,
> many thanks. And if I needed him to, Paul at Ten-Tec
> offered to go above & beyond what I believe any other
> manufacturer would have offered in helping to solve
> the problem. And now, the story . . .
>
> I was getting to the end of the rope. I had installed
> bypass caps in the 961 & Omni where they seemed to be
> lacking. I added gobs of ferrite everywhere I could
> think of (almost . .) I was ready to replace the
> internal audio wiring of my Omni when someone
> "knowingly" told me it was unshielded (upon
> inspection, found that it was not only shielded but
> ferrite beads are on the lines as well). I stripped
> the station set up down to the barebones -
> disconnecting everything but the Omni, Centurion, 961,
> dummy load and a mike - no improvement. I tried
> different mikes. Reworked the station ground. Etc,
> etc ad infinitum
>
> The first glimmering came when I lengthened the
> rig/amp coax interconnect from 3 feet to 6 feet and
> found an improvement. (Hmmm . .) On a whim I stuck
> my 238 tuner between the Omni & Centurion, nulled
> reflected power and completely eliminated the problem.
> (Double Hmmm . .) So I thought there might be a rig
> problem, but first I wanted to try a really good choke
> between the rig and amp. At the same time I got an
> idea on how I could drive an 8 ft ground rod into the
> subfloor almost right beneath the rig. I installed
> the new ground system with a total run of 5ft of 1
> inch braid between rig and rod (a shortening of 7 ft
> from the old connection to the house entry ground rod)
> - and used strict single point grounding for the
> station. The new ground eliminated 90% of the
> RF/distortion and the choke (currently a RadioWorks T4
> Line Isolator, soon to be a homebrew job) eliminated
> the remaining 10%.
>
> Whew, what a relief! I learned at least two things
> through all this - there's a lot of guys on the
> reflector who really want to help, and RF ground
> connections like to be S-H-O-R-T.
>
> Thanks & 73 to all,
> Barry N1EU
>
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