Cleaning valvebases Etc.

[Valvewhiz1]

Hi all,

As part of the restoration of the AR80 I'm working on I needed two ceramic valvebases, I had some I removed from a scrapped AR88 but they were very dirty.

I used the idea I've used before, get a plastic container washing tablet container is ideal, raid the kitchen cupboard and look for oxy clean powder or similar, put one scoopful in to the container, then add very hot, not boiling, water, throw in the valve bases and leave to soak. After a few minutes pull them out and check, they should look like new, if not put them back for a bit longer.

This also works great on switches, variable capacitors as well.

Mmmm! I wonder if it would work on a chassis, must find a bigger box!!

[Radio Wrangler]

I just bung things in the dishwasher, but I avoid bare aluminium because the detergents tend to etch it.

When I designed test gear, the firm's parts specification drawings always required components to 'Withstand a dishwasher cycle with Calgonite detergent'

Back then I thought Calgonite was some strange american substance that might worry superman a little.

David

[G6Tanuki]

An aged radio-amateur of my aquaintance ( now alas passed on to the land of eternally-perfect propagation ) was known to use one of his "Steradent" denture-cleaning tablets to remove crud from things like ceramic valve-bases, antenna insulators and the big ceramic rotary switches he loved to use in ATUs. The 2c39A and 4x150A-type ceramic/metal valves clean up nicely this way too.

[PaulR]

A bit off topic, but when I first started work we made tea in very large aluminium teapots. Eventually the holes where the spout fitted bunged up with all the remains of tea. A couple of Steradent tablets left in over the weekend brought it up shiny and new looking.

[ColinTheAmpMan1]

Originally Posted by Radio Wrangler

I just bung things in the dishwasher....

Cor! I bet SWBO loves that!
Colin.

[Bazz4CQJ]

Originally Posted by Radio Wrangler

When I designed test gear, the firm's parts specification drawings always required components to 'Withstand a dishwasher cycle with Calgonite detergent'

David

Surely, that was just to get the HP Sauce off?

I first heard about dishwasher cleaning some years ago; some American had cleaned the 4 gang tuning condenser from an HRO in his dishwasher. I still find the idea incredible - might try it out on sacrificial test pieces.

Bazz

[PaulR]

It works perfectly. Brings a tuning capacitor up like new and gets rid of all the old oil off the bearings.

A friend who is a mechanic says it also works well on carburettors!

[Radio Wrangler]

It's almost as good as having an ultrasonic cleaner and it can take larger items.

The cleaning action gets to otherwise inaccessible places where staking and other one-way assembly techniques stop you getting at things. Wish I'd known in the 80's. We wrote-off a set of 42DCNFs clogged with muck in an inaccessible place. Dearer than a new dishwasher.

Now why do I have a mental image of someone staggering around Curry's with an autochanger looking for a new dishwasher?

David

[PaulR]

I never thought of trying it on an autochanger...

[Alistair D]

On something like an autochanger would you remove the rubber parts first?

Al

[PaulR]

I imagine you would, together with the motor or any coils. Also the paint would be vulnerable. Maybe better as a "thought experiment" rather than for real.

[Radio Wrangler]

And definitely remove a crystal cartridge!

But there must be some piece of legendary awfulness that no-one would miss?

I'm the guy that says that drug tests and LD50 tests should use spammers and cold-callers not cuddly animals.

David

[G6Tanuki]

A couple of cycles in a dishwasher is a great way to clean-up stuff.

Ages back I acquired for a pittance at a junk-auction a dozen IBM "Model M" keyboards.

Now, anyone who has spent time in the world of IT will know that these are to geeks what NOS boxed GEC KT88s are to audiophools.

Anyway, these Model-Ms were utterly filthy - they came from an industrial environment and were caked with unmentionable levels of encrusted gruesomeness.

A few cycles in the dishwasher, then immersion in a tank of deionised water and a week in a drying-cabinet [5% RH, 30 Centigrade] and they came out looking as if they'd just left the production-line.

I punted them out on The_Auction_Site_whose_Name_Must_Not_Be_Mentioned with a "Buy Now" of £100 a time.

And sold the lot. If you did a "Buy Now" I threw in a long curly cable as a freebie.

That little escapade raised the funds to tax/insure/MoT my cars for a year.

[Radio Wrangler]

Dishwashers for fun and profit!

They never tell you about that in the showrooms....

I think those IBM keyboards were the contactless jobs done with variable coupling transformer coils implemented in the PCB, the keys bringing down metal plates close to the coils.

David

[G6Tanuki]

Originally Posted by Radio Wrangler

I think those IBM keyboards were the contactless jobs done with variable coupling transformer coils implemented in the PCB, the keys bringing down metal plates close to the coils.David

The "Model M" is a contact-based keyboard: the big thing about it is that it uses a "buckling spring" mechanism which results in it rewarding the user with an uniquely satisfying and delightfully-tactile typing experience:

http://en.wikipedia.org/wiki/Buckling_spring

I'm typing this on a "Model M"; it has an "IBM Greenock" manufacturing-date sticker of 1985 on the back.

--G6Tanuki.

[FrankB]

Dishwashers have long been used here to clean tuning capacitors (remove the trimmer micas first),
And even commercial 2 way radios.
One of my 2 waybtech buddies used to take home the chassis from
work and put them in the xyl's dishwasher.
Then after they were thoroughly dry, they replaced all the electrolytics and pots, realigned, and
collected the big bux.
They came out looking new.