Hi Reed,
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Just one note of caution - when pulling the paper covers off the can
capacitors, be careful they are not charged. The can is usually insulated
because it is a part of a negative supply or the bottom capacitor in a series
pair.
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Best regards,
Tom
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----- Original Message -----
Sent: Tuesday, July 10, 2012 11:38
PM
Subject: [TekScopes] Notes about washing
Tektronix Oscillosopes
?
I want to pass on to the forum members the procedures Stan Griffiths has
developed
for washing, cleaning and drying scopes. One salient point,
make sure
the water you
use in these procedures is soft. Hard water has
been proven to leave a
slightly conductive
residue inside transformers
that, over time, causes conductive paths and
eventual failure.
To
control the temperature in my "oven", I use a hot water heater
thermostat
purchased at a plumbing supply house. This is used to cycle,
on and off, a
plug strip with hot plates plugged into it. The thermostat
can be set to
temperatures in the 110-130 degree area which I think is safe
for all parts
in most scopes. Before washing remove the CRT and any
cardboard insulators
placed over filter cap cans. Remove the mesh air
filter before cleaning.
My wash procedure is something like
this:
1. Wet the scope down with luke-warm water. Avoid spraying water
directly
into the transformer(s) or fan motor.
2. Spray the entire scope
with the 10:1 diluted Simple Green so it can
soak
and get the dirt
softened.
3. Scrub all flat parts of the scope with a soft plastic bristle
brush.
Use some undiluted Simple Green in the really dirty areas. A tooth
brush
or long handled bottle brush helps get into tight areas.
4. Scrub
all the front panel knobs with a tooth brush and concentrated
Simple
Green.
5. Spray the entire scope again with the 10:1 Simple Green solution
and
scrub some more in the really dirty areas.
6. Rinse with LOTS of
luke-warm water until you see no more soap bubbles
coming off the
scope.
7. Change to an air-only spray gun and blow as much of the water off
of
the
scope as you can.
8. Put the scope in your "oven" for about
48 hours at about 120 degrees F.
I have plans to rip the guts out of an
old 220 V electric clothes drier
and place them inside an
equally old
refrigerator with holes cut to allow air to circulate. The
drier
temperature control
could probably be used to control the heat and the
drier fan should
supply sufficient air flow
to completely dry the scope
in the prescribed time or less.
Forum members are invited to start a
thread on this topic.
Reed Dickinson
