[R-390] That's more like it!!!

[Cecil Acuff]

Well one things for sure....The Ole List......She ain't what she used to be!

Kinda miss the Ole days...lot of good info got passed around.  Lot of good
humor as well!

Probably a lot easier to manage this group though...

Cecil...
----- Original Message ----- 
From: "Barry Hauser" <barry@hausernet.com>
To: "K3PID" <k3pid@comcast.net>; <R-390@mailman.qth.net>
Sent: Sunday, January 25, 2004 11:38 PM
Subject: Re: [R-390] That's more like it!!!


> I see that Meir answered your first question as he posted his reply to the
> list.  I don't see a reply to your second question.  It appears that the
> general activity level of the list has diminished.  Part of this may be
due
> to the practice of replying off-list -- perhaps to conserve bandwidth,
keep
> a low profile, or, I dunno -- maybe solar flares wiping out the band?
> Anyway, there is the tendency to think -- well maybe the guy got his
answer,
> or I have an idea, but someone else out there is more expert or whatever.
> As for the first question -- I, for one, did not know the answer.  As for
> the second (about why some guy swapped out the balanced connector for an
> SO-239 instead of the balanced one), that sounded like the courtrooms
scene
> in the movies where one of the sides yells out "Objection!  Calls for a
> conclusion!" or conjecture, etc.
>
> Anyway, here goes nothin':
>
> I can't say with any assurance as to why the anonymous modder chose to
> replace the balanced connector instead of the unbalanced with an SO-239,
> however:  It is/was procedure to ground one side of the balanced connector
> when connecting an unbalanced line to the blalanced connector, even when
> using a twinax connector on it.  Also, there are adaptors around that
> convert from twinax to C-connector (like the unbalanced).  One side of the
> twinax is grounded inside the adaptor.  Most (maybe all?) of these
adapters
> are right angle/elbow shaped.  There may be variants that go to something
> other than a C-connector -- perhaps an SO-239 or an N-connector?
>
> So, it may have been a common mod in the functional sense, but doubtful
that
> many changed out the connector altogether.  If a made-up adapter is
> difficult to find, it's an easy matter to make up a twinax to SO-239
cable,
> or a longer coax going from a twinax plug (with one side grounded inside)
to
> a PL-259 plug.
>
> I can offer two theories as to why the Unknown One chose to replace the
> balanced connector:  A.  The unbalanced one looked more "normal" and thus
> likely to be found one day, and/or B.  Rumor or conventional wisdom had it
> that the balanced connection was better.  This may really have depended on
> which was used during alignment.  However, any inherent superiority may
have
> been undone by grounding one side.  Twinax connectors are now commonplace
> and cheap as they were used for computer network cabling.  This may not
have
> been the case or known to the modder at the time.
>
> Of course, this is all conjecture and further persuit may get us into the
> areas of Boatanchor Archeology, Boatanchor Anthropology and even, yes ..
> Boatanchor Forensics.  These are rather unusual fields of endeavor.
> (generally recommended that one keep his or her day job ;-)  On the other
> hand, perhaps someone will unearth an article entitled "Replace that Weird
> Balanced Connector with a Good Ol' SO-239" among some crumbling scrolls or
> musty magazines which would shed further light on the motivations at play
at
> the time.  In the Day's of Yore it was customary and fashionable to
perform
> what are now considered abominations upon vintage and historical objects
and
> there were numerous heretical tracts in circulation.  The pendulum has
swung
> back in the direction of orthodoxy, such that  authenticity is prized over
> practicality,  to the extent that artifacts such as original knobs, tags,
> and even dynamotors are much sought after.
>
> If you wish to restore your R-390 (non-A?), you may be able to fit a
> standard twinax panel connector, or, if not, get another antenna relay
> assembly.  I have a supply of R-390A type available, plus some odd ones
that
> include a gas discharge tube.  I forget now what the difference is between
> the R-390 and R-390A versions.  However, on an electrical/functional
basis,
> what you have there is a fairly standard setup.
>
> Barry
>
>
> > ANTENNA INPUT MODIFICATIONS 1/23/2004
> >
> > On my R-390 someone removed the twinaxial socket on the balanced input
and
> > replaced it with an SO-239. The center conductor of the new connector
> passes
> > thru to the high side of the transformer while the other side is now
> > grounded. Was this a common mod? why wouldn't you just replace the
> connector
> > on the unbalanced input with the SO-239?
>
>
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