[Milsurplus] Re: Plastics turning to cheesecake

[Al Parker]

Hi guys,
    Hue, maybe you, living out there in the great NW (I think), know
something abt this, but I heard it today & was a bit alarmed.  slightly on
the same topic--
    I told a friend, at the Raleigh, NC, 'fest today, that I was kinda
looking for an HP 8640 sig. gen.  He told me that he'd had a few (he has a
small commercial repair shop) but was steering away from them based on
info from knowledgeable sources, and reports he had on failures, that the
plastic used for the bandswitching mechanism (a turret?) was reaching the
end of it's expected life and they've been failing.  Strictly a mechanical
problem, and difficult, if not impossible, to remedy.
    Anybody have more input on this?  BTW, he said the 8654's don't have
the problem.  I'm not familiar with the construction of either.
73,
Al, W8UT
New Bern, NC
BoatAnchors appreciated here
http://www.thecompendium.net/radio/
http://www.hammarlund.info


Message: 5
Date: Sat, 16 Apr 2005 20:13:20 +1000
From: "Brian Clarke" <brianclarke01 at optusnet.com.au>
Subject: [Milsurplus] Re: [The WS No.19 Group] Plastics turning to
cheesecake
To: <Wireless-Set-No19 at yahoogroups.com>, <milsurplus at mailman.qth.net>,
"Hue Miller" <kargo_cult at msn.com>
Message-ID: <011001c5426c$eb299800$0404a8c0 at brian>
Content-Type: text/plain; charset="iso-8859-1"

Could be de-polymerisation of the poly-vinyl-chloride. Well-known problem
with house wiring = great income earner for electricians.
Brian.
  You wondered:
  I wonder: what is going on here. Is the "plasticizer" which lends
flexibility or some softness to plastics based materials, now migrating to
the surface? Or?
  Will all plastics based components meet this fate - the still solid ones
just waiting their turn?