Capacitor from a Hunts Cap Analyser CRB2

[Bushbaby]

Hi All,
Can anyone recognise what type of cap this is as taken from a CRB2 analyser? I assume it a Hunts cap but its NOT an electrolytic.
Unfortunately it has not markings on it.

I've added some pics including the tester which arrived today.

Rob

[attachment=2394][attachment=2395][attachment=2396]

[Yorkie]

Hi All,
Can anyone recognise what type of cap this is as taken from a CRB2 analyser? I assume it a Hunts cap but its NOT an electrolytic.
Unfortunately it has not markings on it.

I've added some pics including the tester which arrived today.

Rob

I think it may be a metal clad ruggedised Mil spec one. After WW2 there were millions of brand new ex WD surplus components, while at the same time, until the makers could get back into peacetime production, there was a shortage of domestic ones, so makers pressed into service ex war surplus components, which were doubtless manufactured to a high standard, and thus, benefited customers (who'd already paid for them once over through their taxes!)

Why was it taken out Rob - just because it was old, or was known or suspected to be faulty?

I don't know if anyone else has any other info, but you see a lot of them in military stuff, and domestic radios made immediately after WW2.

Hope that helps a bit.

Nice looking things those Hunts Cap analysers!

David

[ucl82]

Aren't they usually branded as 'Sprague' or something similar? If so I have seen plenty of caps like it in just Post-War equipment so again supporting what David has said.
They seem to be the same as the usual capacitors encountered (Hunts, TCC etc) but in a metal case. A forerunner to the Metalmite perhaps?

[Bushbaby]

Hi David/Josh,
I don't know why it was removed as it came with the tester so I can only assume its faulty (pity I haven't a working cap tester to try it - ironic!).
I would agree with both of you that this is probably a hi spec component to I'll assume it needs something 'butch' to replace it.

Regards

Rob

[Bushbaby]

Just as a matter of interest, I've tested this on my ESR meter and it show a good reading. However, with no markings how can I test if this is indeed an electrolytic and the polarity?

Regards

Rob

[ucl82]

Hi Rob,
If it is an electrolytic it would definitely have either a + at one end or have one end coloured red. Maybe both of these things. However, if there was a case marking it could have become rubbed off. You could always sit under a strong light and try breathing on the case to see if there's any signs of old marks?

If it is a non electrolytic cap I'd suggest replacing with a 1000vdc component to be on the safe side, if the voltage rating is unknown.

It is interesting to see it was mounted in a clamp. I have only ever seen electrolytic capacitors mounted this way and it appears to be far larger than a typical non electrolytic cap.

Josh.

[Bushbaby]

Hi Josh,
I'm guessing that it may once have had a sleeve with the markings on this. I don't beleive that they would have put a component in this test instrument that was unmarked?

I've had a good look and there are no markings at all - very helpful!

Regards

Rob

[tiv48]

the only thing i found on google images is this so that cap looks like 1mf no electrolitic
rob t

[kevin.Hoyland]

[attachment=2406]Hello Rob.

Hope this will help you the Capacitor in my Tester is unmarked. The other CRB2 i have and is the best of the two the capacitor you have is not fitted in it.
Regards Kev.

[Yorkie]

I'm certain that it's not an electrolytic - much more likely to be say a 0.1uF. I've attached a pic of the underside of a 'Barker 88' chassis, c 1945 from which you'll spot several similar ones, with an indented band around each end of the metal jackets. I've taken a close look and they are indeed Sprague make. Barkers were a furniture store and had radio sets made for them to sell in their stores and the sets were branded 'Barker'. It's said that '88' stands for 8 valves, 8 Watts output from a push-pull pair. Barker sets seem to have used whatever valves and components that could be found at the time. EG, the listed output valves were a pair of 6F6G, but the data says that alternative valves may be found, such as 6V6G, KT61, or KT63. I've not checked to see if those are direct equivalents, but it's not relevant to this post anyway - it just reaffirms that in the immediate post-war years, many valves and components were either ex WD surplus, or were still coming off the same assembly lines as had been used for the war effort before switching to domestic production, so radio manufacturers used whatever they could lay their hands on.

As an aside, drifting yet further off topic, ironically, though military equipment had to be reliable and rugged, it didn't need to be long lasting - I believe that the average life of a Lancaster bomber at the height of the war was just 19 weeks, and indeed, many aircrew died not due to hostilities but crashed during training, so 1155s and 1154s and the like, didn't need to last even a year from a pragmatic point of view. Conversely, domestic radios used in a less hostile environment were in use daily for many hours, and needed to last several years.

For me, it's as much the socio-economic history of these old sets and pieces of test gear that as fascinating as restoring and owning them. I guess that's partly due to my being of a similar vintage - VE day - which signalled the end of the war in Europe, was five weeks before my sixth birthday!

Hope you soon have the Hunt's analyser working Rob!


David.