Test Equipment Project. Quiz.

[David Simpson]

What is it ? David

[TonyDuell]

A piece of sheet metal with some holes in it

[Could not resist...]

[kellys_eye]

Power supply?

Two holes at top look cut for fuse holders, the three along the bottom cut for binding posts.

Large cut-out for meter, others for pots/switches.

Wild guess.

[The Philpott]

Hand-fettled one-off project by someone? Many of those holes look carefully hand-made, not machine punched. Although the scallops in the edge suggest that at least the casing was a standard item

[David G4EBT]

The two holes at the top and the three at the bottom look like they're for 4mm sockets, which need a little notch to stop the sockets from rotating once they're fixed.

Certainly looks like a front panel, and a 'busy' one at that, with lots going on! (Can't think what the oblong slots with rounded ends could be for).

No indication as to size, but I'd suggest about 15cm x 7.5cm (6" x 3").

I came to these conclusion by using the time honoured 'SWAG' technique - Stupid Wild Ass Guess

[David Simpson]

4" x 8" aluminium sheet, 1mm thick(slightly thicker than the original).
This is a teaser. It took me ages to make, using the original faceplate off an as yet undisclosed item of vintage test equipment as the template.
An NOS GET116 in its heatsink to the first guy to cotton on.

Regards, David

[Radio Wrangler]

Hmmm... let me guess... valve tester?

David

[dave cox]

Avant-garde potato masher ?

[ms660]

Looks like holes for two grab handles there.

Avo related?

Lawrence.

[ms660]

Anything to do with an Avo transistor analyzer?

The shape kind of looks familiar.

Lawrence.

[David Simpson]

Lawrence, you win the prize. The faceplate off an old scrapped AVO Tr. Analyser Mk1's Battery Box.
But for what madcap hybrid simpson scheme ?

Regards, David

[ms660]

I would have got it sooner but it looks like some extra cut outs have been added to the original?

Sadly I wouldn't find any use for the prize David, maybe you keep it or donate it to a runner up or something.

Lawrence.

[David Simpson]

Folks, time to let the cat out of the bag :-
For nostalgia sake, and to pay homage to AVO Transistor Analysers of yesteryear - have fitted a Hong Kong All-in-One Component Tester(£9.19 on eBay) into an old redundant Mk1's Battery Box's framework.
Not quite finished, and am thinking of fitting the whole thing into a nice old wooden case from the Clare Loop Tester, (mentioned in another post).
My thanks to Pamphonica for recommending the Chinese tester, and the atlas DCA55. I've hundreds & hundreds, if not a thousand or so, transistors & diodes to test & catalogue. AVO Tr. An.'s are great to use from time to time, but laborious. Best just to use them for design &/or characteristic tabulations.
The Chinese Tester with just its wee lever locking connector & exposed pcb, and the DCA55 with just its flyleads & wee spring clips, would certainly benefit from a more robust container & connections for a lot of repetitive work.

Regards, David

[David Simpson]

Well, I guess that's it just about finished. Fitted nicely into the old wooden case which held the CLARE V133 Earth Loop Tester(Thread post on the 24th). Poor old case was much scratched, pitted & stained. Spent as much time tarting it up as was spent on the electronics.
The reason for this quirky quiz thread was to encourage folk to "think outside the box" when it comes to using & adapting new & old test equipment. Not to blow my own trumpet - too old in the tooth to fanny about like that.
The wee Chinese tester cost less than a tenner, and the rest came off the spares & junk shelves & cost next to nothing. I appreciate that not many folk have an old spare CT446 Battery Box. But suitable yaxley switches, moulded enclosures, banana plug sockets, clips, wiring, etc., can all be found dirt cheap at junk sales, or other venues, or scrounged for nowt off helpful Forum folk.
The St1 & St2 switch positions are Standard Ref transistors, kindly tested on his two testers, & supplied by Pamphonica :- OC81D PNP, and 2N3904 NPN.

Regards, David

[Pamphonica]

The worrying thing about this project (which I was slightly privy to) is the obvious effect it is having on David's ability to focus (his camera, that is). Was the project so stressful that generous "wee drams" had to be administered orally? Or is it just that the macro-mode on your camera is playing up?

Anyway, another very fine wooden-cased special from DS. (and yes, those little Chinese all-in-one testers are remarkably useful)

Jeremy

[Station X]

Originally Posted by Pamphonica

The worrying thing about this project (which I was slightly privy to) is the obvious effect it is having on David's ability to focus (his camera, that is). Was the project so stressful that generous "wee drams" had to be administered orally? Or is it just that the macro-mode on your camera is playing up?

Jeremy

I find it very difficult to take good in-focus macro shots indoors under artificial light. For me, taking such pictures out of doors under natural light yields better results, but shadows can be a problem.

[David Simpson]

Right enough, Jeremy & Graham, I need more practice in close-up photography. If I had the room, a dedicated stance with a fixed wee tripod or angle-poise contraption would be ideal. But, as Jeremy will tell you, I just don't have the space.
This was also my first attempt at etching & inking a blank wee sheet of aluminium. A Rotring stencil, a sharp hobbyist scriber, and a 0.3 Staedtler pen. It looked fine when first finished, but after two spray coats of acrylic lacquer to protect everything, the lettering & numbering faded somewhat. Still clear enough, but nothing like AVO's original lovely lettering on CT446's.
When considering making this wee faceplate, and the restoration of the AM Oscilloscope Type11's steel faceplate, I did make some enquiries with commercial producers. The quotes were astronomical, and they would only consider a run of 100 at least ! Stuff that, as the actress said to the bishop.
There was an old boy who lived locally a number of years back, who used to make lovely stampings &/or lettering on brass sheet & tin. As part of his scale model steam engine hobby. Sadly, he passed away some time ago.
I've lost the details of the kind Forum guy who provided the old CT446 chassis, for spares, several years ago. It helped in the repair of my recently acquired Mk2, and in the construction of this project. Many thanks anyway.
If anyone is considering making an enclosure for one of these cheapo Chinese component testers - make sure you cover the exposed pcb & all the diddy wee chips & components, and the screen, with masking tape whilst you measure up & mark & move around you bench during construction. The pcb does have two 6BA holes on either side which lend themselves to suitable mounting(back to the actress again). I'm guessing that they are a surplus run of fittings, originally destined to be inside a moulded hand-held device.

Regards, David

[David Simpson]

Well folks, I guess this thread has run its course. Have made a start on my heap of PNP transistors first, and am relocating them from a 45 year old cardboard box to a new component container. The Rapid Electronics plastic box is very sturdy & well built.
The atlas DCA55 fits nicely inside the recessed lid of the wooden case, which can be quickly in-hinged & used separately if needed.
I've even started to test a rare "Crystal Triode" - GEC's 1953 Germanium Point-Contact GET1.
The atlas doesn't recognise it, and the cheapo chinko thinks its a back to back double capacitor! So will test it on my Mk2 CT446, using the GEC spec sheet kindly provided by Andrew Wylie(Mr Transistor) several years ago.

Regards, David