[Hallicrafters] AC/DC Halli's, Grounds and HUM

[Phil Atchley]

Hello All
I have a Halli 5R10A (5 tube AC/DC set) that I recently completely recapped
and went through with a fine tooth comb.  While I was doing the refurb I
installed a new line cord with a  "polarized" (one prong fatter) line cord,
making SURE that the neutral line (fat prong) is tied to the B minus side of
the power supply (as it should be).  The chassis then connects to this B-
lead through a coupling capacitor for RF bypassing (AND AC line isolation).

The set shows ONE big quirk though (and it did when it arrived here before
the recap).  IF I tie the ground lug (connected to chassis) on the 3 screw
antenna strip to the station ground I get a LOT of hum.  The set DOES NOT
like to be grounded.  This precluded using my antenna/rig select switches to
apply an antenna to the set UNTIL I lifted the jumper from the ground screw
to one of the antenna screws and operate the set in the "isolated" antenna
mode (I.E. Doublet setup).  Doing this the hum does NOT show up and
everything appears to be fine.

Question 1:  Is this typical of the Hallicrafters AC/DC rigs of 5R10A, S-38
vintage or should I be looking for a problem somewhere? (I don't remember
this happening on my S-120 though back in the barracks in '63 I don't think
I used a ground)

Question 2:  Does anybody have the schematic and service notes for the 5R10A
that they could scan and send me?  The set is so simple one can really do
all the work without them (as I did) but it'd be nice to have.  (No, the set
isn't on the BAMA site).

73 de Phil  KO6BB
Loving home provided for wayward Boatanchor Receivers
ko6bb at elite.net
Merced, Central California
37.18N 120.29W CM97sh





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