Re: Old AR88 restoration tips?


Jim wrote:

On Thu, 30 Jul 2009 06:11:50 +0100, "Brian Reay" <seewebsite@xxxxxxxxxxx>
wrote:


"Andy" <andy@xxxxxxxxx> wrote in message
news:h4qc62$luc$1@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx

I have recovered an AR88 from my parents loft, I must have left there 15
years back. I remember the the AR88 was prone to capacitors drying
out; are replacements available?

What is the best way to clean the black greasy fluff from the chassis and
valves?

Any other tips?

Sometimes you can open up the old capacitors, remove the innards, and fit
new ones inside. I've even heard of old resistors being "drilled out" and
having new modern ones slide inside.

Remove the "fluff" with a paint brush and a vacuum. Those grease removal
wipes which smell of citrus fruit can also help*.

On first power up, use a variac to slowly bring up the mains supply.

At some point, replace any rubber insulated wires. If you don't like the
idea of modern wire, try and get some "empire cloth" sleeving.

It goes without saying to be careful of the voltages etc.

*Starship may have some cleaning tips, he seems to be a professional cleaner
;-)

Just like 'LVN.

You'll probably need to replace all of the decoupling
capacitors

Not necessarily.

I have not replaced a single capacitor in any of the WWII gear that
I've broiught back to life. I outlined the methods in another post

and don't forget to check and replace any
bias resistors which may have moved in value, or replace
both Rs and Cs as a matter of course.

That rather depends on what philosopy the OP wished to bring to bear
regarding this piece of kit.

He could do anything from bringing the old girl back to life in the
way I suggested keeping it as near original as possible, to replacing
just about everything in an attempt to get maximum performance and
'improve' it. It's his call.

Personally, I've never replaced a resistor either, accepting that
performance may be below optimum - but one can use modern stuff for
that.

As I recall, the HT smoothing/reservoir capacitors were
paper rather than electrolytic.

But can still be reclaimed by the method metioned.
--

from
Aero Spike
Not a member of RAOTA for 28 years 1981 - 2009
Not a member of the RSGB for 50 years 1959 - 2009
.

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