[Hallicrafters] SX101 Drift Problem

[Al Parker]

Bill,   (I think it was you who started this)
    You might want to check/swap-out the osc. and mixer tubes.  I was
having the same problem with my latest SX-101A, and did replace a cupla
tubes.  Don't remember at the moment which of those it was, but it did
help immensely (mighta bn the 12BY7).  This was well over a yr ago, I
hadn't done anything else to the rcvr, it's all original, and the
dampchaser works.  (grid bypasses in the IF?????   ain't no such in the
101A)  (I've always wondered why they used a 12BY7 as an osc. in these -
it's stout enuf to use as a driver for the finals in the HT-32 and many
others.  Develops a lotta heat.)
73,
Al, W8UT
New Bern, NC
BoatAnchors appreciated here
http://www.thecompendium.net/radio/
http://www.hammarlund.info


----- Original Message ----- 
From: "Rbethman" <rbethman at comcast.net>
To: "Edward B Richards" <zuu6k at juno.com>
Cc: <wd4hen at bellsouth.net>; <hallicrafters at mailman.qth.net>
Sent: Tuesday, May 11, 2004 7:15 PM
Subject: Re: [Hallicrafters] SX101 Drift Problem


> Sounds like the grid bypass BBODs in the IF stages were also replaced.
>
> Those should be left alone unless DEFINITELY testing bad.  The whole
> characteristic of these old caps in THAT specific chain WERE figured
> into their use.  You may want to relocate them AND put them back where
> they were.
>
> My SX-101 MkIII has had MINIMAL recapping just for that specific
> reason.  I don't have to chase the knob all over the dial.  The damp
> chaser is in place, and drift is minimal.  Yes these old girls drift,
> BUT, it isn't that bad at all.
>
> Bob - N)DGN
>