[R-390] R-390 (non A) power plug.

Tue, 09 Apr 2002 16:28:08 -0400

Jim:

The non-A is non-cost reduced version so came with a gen-u-wine, heavy duty,
deluxe power connector setup, as opposed to the cheaper terminals and
stamped cover of the Non-A, re-designed primarily to free up funds for
hammers and coffee pots.  (Naw, I like my A's and non-A's alike, as well as
SP-600's and even a RAK 'n RAL, BC-312/342 or two.  An equal opportunity
boatanchorist.)

Anyway, connect the green wire to the ground pin of the chassis plug.  Do
you have the correct connector?

Put the black hot wire to the fused/switched pin as recommended by others --
it's a safety requirement, and the neutral wire goes to the continiously
connected pin.  The 4th pin was for 28 volt accessories and is used in the
'391 for the autotune.  So forget about that one.

You can use the chassis ground terminal for earth ground, but earth
grounding might be better done solely to the coax shield at the point of
entry of the downlead.  Any opinions on this?  R-1051's have a similar 3-pin
version of that power connector and some R-390A's are fitted with the Navy
addon that converts fromt the raw terminals to the 3-pin Navy type.  The
1051's also use the ground pin, and also have separate grounding terminals
for the case.

I think most tie the chassis to earth ground in addition to the ground
through the power connector.  What say the group?

Barry

----- Original Message -----
From: "Jim Temple" <[email protected]>
To: <[email protected]>
Sent: Tuesday, April 09, 2002 4:14 PM
Subject: Re: [R-390] R-390 (non A) power plug.

> Thanks for the insights.  The only unanswered question is the grounding.
>
> Within the cable housing that attaches to the radio are:
>
> 1.  Post "C".  This, according to the schematic, goes to the radio
> electrical ground.
> 2.  Inside the connector housing, attached to the interior wall of the
> housing, is a post with nothing attached to it.  I would assume that if
this
> was attached to the outlet ground, it would provide a ground path to the
> radio frame.
>
> I have a curious mind, so I began thinking.......(watch out!!).
>
> The power outlet ground, on a R-390A, is attached directly to the radio
> frame. At least with mine this is so.  On the R-390, it seems that there
are
> two paths to ground the radio.  1.  Post "C" of the power connector, and
2.
> The radio frame.
>
> I would assume that both are, practically speaking, the same.  So
attaching
> to one or the other would accomplish the same purpose.  On the other hand,
> attaching to both, at the same time (within the housing), would probably
> accomplish the same chore, or could there be possible ground loops
> associated to grounding to both the radio electrical ground (power plug
post
> C) and the frame ground at the same time??  Also, within the attaching
> housing, the ground could be put in series or parallel  (One ground wire
> attaching both points, or one wire branched to each post separately.
>
> My experience says that multiple grounds can introduce unwanted feedback.
> Hence the importance of lead dress and routing.
>
> Am I being too persnikity here, or is this a valid question??
>
> Jim
>
> ----- Original Message -----
> From: "Roy Morgan" <[email protected]>
> To: "Jim Temple" <[email protected]>; <[email protected]>
> Sent: Tuesday, April 09, 2002 3:30 PM
> Subject: Re: [R-390] R-390 (non A) power plug.
>
>
> > At 02:28 PM 4/9/02 -0400, Jim Temple wrote:
> > >My new r-390 (NON-A)
> > >
> > >I have obtained a length of 3 wire and am installing it now.
> >
> > I assume you mean a three wire line cord with a grounded plug.
> >
> > >1.  Does it matter which lead, hot or common, is attached to F101?
> >
> > YES, it matters.
> >
> > >  Would it
> > >be best to wire the hot (black) wire to  post "D", which is attached to
> > >F101, for purposes of efficient fuse protection?
> >
> > SAFE is the word not "efficient". The hot wire (black in US Standard
> > cables) goes directly to the REAR terminal of the fuse holder (through
the
> > line filter in the case of R-39x radios).  This does two things:
> >
> >   1) Reduces to the minimum the amount of line voltage exposure inside
the
> > radio after the fuse blows.
> >   2) Protects you (to some degree) from contacting the line voltage as
you
> > replace the fuse.
> >
> > >2.  Would the power plug ground (green) best be utilized by attaching
it
> to:
> > >     a.  Post "C"?
> >
> > Yes, (I assume contact C is the one going to ground..)
> >
> > >     b.  The housing ground post?
> >
> > Do you mean the threaded center mechanical clamping post?  NO.  Do not
> > depend on that for grounding.. do not use it.
> >
> > Roy
> >
> >
> > - Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
> > 7130 Panorama Drive, Derwood MD 20855
> > Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
> > [email protected] --
> >
> > _______________________________________________
> > R-390 mailing list
> > [email protected]
> > http://mailman.qth.net/mailman/listinfo/r-390
> >
>
>
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