----- Original Message -----
From: "Lord Isildur" <mrfusion@umbar.vaxpower.org>
To: "Geoff Roberts" <geoffrob@stmarks.pp.catholic.edu.au>
Cc: "Gunther Schadow" <gunther@aurora.regenstrief.org>;
<port-vax@netbsd.org>
Sent: Friday, May 25, 2001 10:58 AM
Subject: Re: VAX 6420: what KDB50 cabling? RA91 anywhere?


> there is very certanily a condenser coil and compressor and cooling
fans
> in the bottom half of my TU78,

Certainly.

> with hoses carrying coolant

No coolant, just air, or vaccuum.  The intercooler is to cool the air
down, which is hot after being compressed, and
there is a water trap arrangement, as this will cause condensation as a
result.  Bear in mind that liquid is mostly incompressible, so you would
have a pump, not a compressor if it were liquid cooled.  This is a
compressor.  (I use it in my shed now, great tyre pump, and air for
blast cleaning)

>(apparently)

Sounds like you might have trapped water in the system, not surprising
if it's not in a controlled environment.
This could easily be mistaken for coolant, if you see liquid in there,
that's what it is.
Think about this.  What in a tape deck would produce so much heat it
would need to be liquid cooled?

> to and from the tape unit itself... *grin*

Yep.  Air lines.  The tape motors are air driven turbines.  The entire
deck runs on compressed air,
and the autothreading runs on vaccuum.
Swing open the tape deck and have a look at the back of it and you'll
see what I mean, it's a maze of tubes
and pnuematic servos etc.

Cheers

Geoff in Oz