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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 12th Aug 2019, 9:05 pm   #1
G6Tanuki
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Default Crumbly RS capacitors.

We're all familiar with the horrors of 1950s/1960s brown- and black-Hunts moulded capacitors whose encapsulation crumbles away like a vampire-exposed-to-daylight.

But it's not just Hunts that suffer this way: here are a couple of photos of early-1970s RS capacitors that have clearly passed-over to the dark side....

Not what you want to see in the grid-coupling capacitors to a push-pull pair of 6L6, I think you'll agree.
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Old 12th Aug 2019, 9:17 pm   #2
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Default Re: Crumbly RS capacitors.

That particular type do seem to crack and crumble, seen lot during my time in the trade, sold a nice amplifier here some time back, full of the things, all split open, still gamely working a bit though!.
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Old 13th Aug 2019, 11:59 am   #3
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Default Re: Crumbly RS capacitors.

Paper capacitors in general tend to do that.
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Old 13th Aug 2019, 1:07 pm   #4
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Default Re: Crumbly RS capacitors.

These are very old and I remember changing them years ago.
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Old 13th Aug 2019, 1:29 pm   #5
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Default Re: Crumbly RS capacitors.

Quote:
Originally Posted by HamishBoxer View Post
These are very old and I remember changing them years ago.

Yep, you tell by the "made in England" writing on them

- from the good ol' days before we were "all Bankster ridden "
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Old 13th Aug 2019, 1:38 pm   #6
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Default Re: Crumbly RS capacitors.

RS didn’t make any caps as far as I know. They were sourced from the main manufacturers with an RS logo.
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Old 13th Aug 2019, 1:56 pm   #7
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Default Re: Crumbly RS capacitors.

I heard that Plessey made a lot of their capacitors.
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Old 13th Aug 2019, 2:01 pm   #8
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Default Re: Crumbly RS capacitors.

I never really liked (feel free to interpret as "trusted"....) the way that RS had all sorts of things own-labelled- why not let things for sale be labelled Hunts or Erie or National Semiconductor or whatever, unless perhaps they were "B" grade items that the OEM didn't want going out with the original brand.

Those capacitors look rather like a (possibly later) grey plastic-packaged version of the brown and black-cased Hunts types that we all know and don't love. Possibly, the original encapsulent had a degree of suppleness/flexibility for the first few years that catered for thermal expansion/contraction of the inner contents but it hardened and became brittle over time, with the resultant cracking from differential expansion.

Once again, this looks like a component of not particularly exalted quality that continued in use beyond its expected lifespan by quite some margin.
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Old 13th Aug 2019, 2:38 pm   #9
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Default Re: Crumbly RS capacitors.

Quote:
Originally Posted by turretslug View Post
I never really liked (feel free to interpret as "trusted"....) the way that RS had all sorts of things own-labelled- why not let things for sale be labelled Hunts or Erie or National Semiconductor or whatever, unless perhaps they were "B" grade items that the OEM didn't want going out with the original brand.

They are still at it with their "RS Pro" line. Allthough they now don't often rebrand individual components with the RS Logo, you never quite know what you are getting bar it will be a second tier manufacture i.e not Panasonic or Rubycon but "Jackson" capacitors etc.
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Old 13th Aug 2019, 2:56 pm   #10
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Default Re: Crumbly RS capacitors.

It is wrong to assume all grey RS caps are the same. A type of 250/400V axial is a glossy
plastic cup containing the capacitor with the open end filled with a coloured resin. This
type (also seen with a black body) is very reliable. Later caps of the Hunts design were
labelled Erie. Some of these had a red case and have a greater longevity.
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Old 13th Aug 2019, 3:55 pm   #11
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Default Re: Crumbly RS capacitors.

https://www.vintage-radio.net/forum/...ad.php?t=98964
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Old 13th Aug 2019, 4:39 pm   #12
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Default Re: Crumbly RS capacitors.

I have examples of the same capacitor marked ERO, a brand of Ernst Roederstein in Germany, who made capacitors from the 1920s until they were taken over by Vishay in the '90s. But it may not be as simple as Roederstein making them for RS. Like your RS-branded caps, the ROE items in my pic below state 'Made in England' but I am not aware of Roederstein having a manufacturing plant in the UK. Nor is the ROE marking in their normal trademark style, inclined within a square. Most Roederstein product lines are instantly recognisable, either resin dipped or wrap-and-fill, whereas these 'Made in England' items break the mould, as it were.

Either whoever made them for RS also made them for Roederstein, or the 'Made in England' is not strictly accurate. Funny how the font of 'Made in England' is different to the other printing on the caps, and rather familiar when compared with a Hunts Moldseal. I've seen Moldseals badged for RTC in both red and green moulding compound although all other details were identical to the normal Hunts edition (albeit with a null date code of BBB).

The shape of the moulding ends of these grey ones is different but could they actually be Moldseals in disguise?

Quote:
Later caps of the Hunts design were labelled Erie.
Erie took over A.H. Hunt in 1969 IIRC, so this isn't a re-badge as such.
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Old 13th Aug 2019, 5:18 pm   #13
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Default Re: Crumbly RS capacitors.

Quote:
Originally Posted by turretslug View Post
I never really liked (feel free to interpret as "trusted"....) the way that RS had all sorts of things own-labelled- why not let things for sale be labelled Hunts or Erie or National Semiconductor or whatever, unless perhaps they were "B" grade items that the OEM didn't want going out with the original brand.
They were trying to promote themselves. As far as I know they didn't use any second-grade units (they weren't Sinclair, selling below-spec transistors and IC's). They had the buying power to ask for branding, and get it.

I recall a rep from Electrolube (suppliers of encapsulating resins, and aerosol cleaners and lubricants) explaining that the Electrolube brand is trusted and their products are often copied, never equalled, "except by RS. We supply to RS but they want their own branding. But when a company offers you a contract to buy 10,000 cans of Fluxclene a year, but they want their own label as part of the deal, you accept."
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Old 13th Aug 2019, 6:16 pm   #14
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Default Re: Crumbly RS capacitors.

I don’t recall Radio Spares (RS) from 50 years ago being second tier, we used a lot of their components and they worked as well and sometimes better than named varieties. Never a problem with support either, if there was a failure the rep promptly sorted a replacement.
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Old 13th Aug 2019, 6:27 pm   #15
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Default Re: Crumbly RS capacitors.

I don't think they were.
From personal experience though I would seriously council again using "RS Pro" stuff now for critical commercial repairs. I had a few "bounces" within the warranty period (not straight away) due to using their caps branded thus - sometimes you really do get what you pay for.
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Old 13th Aug 2019, 7:21 pm   #16
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Default Re: Crumbly RS capacitors.

I remember the RS rep telling us that, like supermarket own-label stuff, they could control the overall appearance of the product even though the OEM may have changed several times...consistency and all that. For example, he pointed to our 'RS' oscilloscope, saying 'ah..good scopes those, but we changed supplier when the sterling-yen rate changed'. After he went, I took a closer look at the scope and found I could peel off the front vinyl label, revealing the original one still underneath; a japanese 'Leader'.

The RS-Pro stuff is, as far as I can see, RS's response to the bargain-end of the market: you beat 'em or join 'em.

I think you can still buy with confidence though, for example I had some RS-Pro smpsu's and they were made by Meanwell...a well regarded maker.

Some RS-Pro stuff isn't even re-branded, for example we had some proximity sensors a while back and they were made by Micro-Detectors, an OEM who also subcontracts for Erwin Sick, amongst others.
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Old 13th Aug 2019, 8:00 pm   #17
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Default Re: Crumbly RS capacitors.

As a slight aside, similar-looking large grey coupling caps appear in 1950s Pamphonic amplifiers proudly carrying the Pamphonic brand! I wonder why they bothered. They did that with their speakers as well.
However, my tests on all those "Pamphonic" grey caps in that amp (a 1958 Model 3001) while doing restoration proved that they are all still perfect. No leakage or cracking.
That's more than I can say for those horrid orange electrolytics, every one of which had to be replaced (over 20 in all)!
-Jeremy
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Old 13th Aug 2019, 10:33 pm   #18
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Default Re: Crumbly RS capacitors.

RS was the 'one stop' supplier of components to the radio/TV trade back when they started and R&TV manufacturers restricted parts to their own dealers. RS could supply most general parts and many special parts by return of post. They had reps on the road who would call into the shops in their area on a regular basis. They had samples in their little grey box to show you and the prices were competitive.
They had a catalogue stapled together from sheets printed on a Gestetner printer.
They had a reputation for quality parts, at least as good as the major makers, who often made the parts for them anyway. They grew by expanding into a wider range of electrical/electronic parts to be one of the largest distributors of these products.
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Old 14th Aug 2019, 11:06 am   #19
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Default Re: Crumbly RS capacitors.

Dubilier ?

Lawrence.
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Old 15th Aug 2019, 9:23 am   #20
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Default Re: Crumbly RS capacitors.

Lavender and blue 1980s RS electrolytics, made in Japan. Are these Panasonics?
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