THIS ELKO EYV ELECTROLYTIC CAPACITOR IS A "PULL" - REMOVED/WORKING (BUT OLD - YES)
Ex obsolete (no longer has a useful purpose) Rohde & Schwarz Test Equipment
The WORKING equipment this was removed from (today) was very specialised audio analysis Rohde & Schwarz test equipment, German made. The functions of the equipment are no longer relevant in today's world of digital technology so I have carefully dismantled and parted out "useful" components that I am hoping will find a new life in other equipment.
This capacitor was part of the power supply filter network, having clean stable DC was extremely critical to the functioning of the original equipment.
Unfortunately a lot of my test equipment has found new homes (stupid me for selling them!) so I do NOT have any means of checking the characteristics of this capacitor but I do know the equipment was running to specifications and I did look at things like the ripple levels of the power supply, no problems at all. The beauty of these ROE (Roederstein) capacitors is their long term reliability & stability and they are especially favoured in high quality audio circuits.
ROE
So who is/was ROE? The company behind the market brand was Roederstein, they started manufacturing film capacitors way back in 1925 with aluminium electrolytics being added in 1955, the company was based in Berlin. In the early 1990's, Roederstein was acquired by Vishay - no more ROE but their product range lives on and even today you can purchase "modern" VISHAY/ROE capacitors although I have no idea if Vishay maintained the high production quality of Roederstein.
Original Roderstein capacitors are right up there with Siemens and Spraque in terms of quality, production standards and reliability over the long term.
It is IMPORTANT to read my information page about both new AND old stock electrolytic capacitors ... please go HERE
ROE (Roederstein) Germany
ELKO Series
Type EYV
Circa 1990's - (yes, 30 years old! But still working fine)
Aluminium Electrolytic
Can package PCB mount
-10 ~ +50% value tolerance with long term stability
Very long useful life: 15,000 h at 85 °C but this at the extremes of operating environment temperatures. At 40C the useful life is quoted as at least 200,000 h continous (that is 22 years having never been turned off!)
Low ESR
High ripple current capability
High resistance to shock and vibration
Operating temperature range -40 ~ +85C
22000uF
15V DC
Dimensions: 34mm diameter x 52mm height
Weight: 50g (this is why the capacitor has 4 terminals, 2 of which are intended as supports)
Most often these are used in linear power supplies as part of the DC filter network.
COSMETIC CONDITION:
Excellent physical condition
Absolutely no signs of stress or leakage! Not really surprising because the original equipment was only used periodically and certainly not continuously.
Untested characteristics (see my comments above about this) however the equipment this capacitor was removed from was fully functioning but of little use in today's world, being very outdated technology. Although I powered up the equipment for quite a few days (trying to understand what the equipment was supposed to measure!) it is a fact that over time of NON-USE, the capacitance of these EYV caps can go lower but when put back to use, the capacitor "reforms" and your capacitance comes right back up (if it was low in the first place), although the tolerances of the aluminium caps are pretty wide in anyway.
4x PCB mounting pins on the base
What? I hear you say, why 4 terminals?
Only two terminals matter, number 1 (positive) and the terminal with a - marked above it (negative) I have included a base diagram to help understand the terminal layout. The terminals 2 & 3 are used for mechanical stability only and not to be used in the filtering circuit. Just for interests sake I measured the DC resistance around the terminals 2 & 3. I measure infinity between these two terminals BUT I do get a very high reading (11M Ohm plus) between either terminal 2 or 3 and the capacitor terminals 1 or -. I cannot find any documentation about why this is so however.
