Unusual 4-leg safety cap

[Jon A.]

This is in my 1976 Electrohome. Is anyone familiar with this kind? If so, are they failure-prone like the white Zenith and Magnavox caps?

I've put in a lot of hours on this set and have it working fairly well, I can't have it blow up now.

Grr, flipped photo again.

[zeno]

Dont think I ever seen one. Looks like it came
from Europe.

73 Zeno
LFOD !

[dieseljeep]

Originally Posted by zeno

Dont think I ever seen one. Looks like it came
from Europe.

73 Zeno
LFOD !

The ERO German caps were usually good quality.
I wonder, if Zenith named American Radionic, vendor of the year at one time.
The Magnavox replacements, were still made by them.
BTW, I took the hammer to the first one I changed. It was an oil cap and had a rubber band holding something together.
Maybe it was the rubber band that caused them to fail.

[Jon A.]

Yeah, I researched ERO caps last night. ERO is now Vishay. I found a post by Brian on ARF saying GE used blue ERO caps to replace the originals. Geez, did I use enough acronyms there?

American Radionics probably got a similar branding. Makes me think of the Dodge Omni/Plymouth Horizon being named 1982's "Lemon of the year".

By the way, what are the voltage and capacitance ratings of Zenith's 800-860 cap kit? I can't find this info anywhere. I have two of these kits and had one out for a look. The cap itself is marked 22-7504-01.

[N2IXK]

Originally Posted by dieseljeep

The ERO German caps were usually good quality.

The ERO electrolytics used in the Quasar "works in a drawer" sets were a common failure point...

[dieseljeep]

Originally Posted by N2IXK

The ERO electrolytics used in the Quasar "works in a drawer" sets were a common failure point...

Electrolytic caps were always a weak point, no matter what firm made them.

[centralradio]

The old Zeniths used those orange four legged safety caps in their sets.I remember at my friends shop that we replaced them alot.

[dieseljeep]

Originally Posted by centralradio

The old Zeniths used those orange four legged safety caps in their sets.I remember at my friends shop that we replaced them alot.

I don't remember the orange Spragues failing. It was good service practice to replace the white ones, whether they failed or not. Maybe some shops replaced the orange ones, just to be sure.
I was part-time and didn't handle the volume of work that many of the firms did. Some of the shops used to boast, 20 to 25 service calls a day, according to Electronic Servicing or similular magazines.

[old_coot88]

Originally Posted by dieseljeep

I don't remember the orange Spragues failing.

Same here. Never saw an orange drop as original equipment in a Zenith.

It was good service practice to replace the white ones, whether they failed or not.

Yup, standard SOP.

[Findm-Keepm]

American Radionic made the original white caps - Zenith and GE used these. Magnavox used a grayish American Radionic cap in their modular chassis (703744-X regulator sets, remember those?) Both Maggie and GE used ERO (Roederstein of Germany, ERO on the cap, now part of the Vishay group) as replacements - both were Blue bodied 4-lead caps. Zenith used 4-lead polypropylene orange drops - basically, their 716P dielectric, with heavier foil and a 4-lead fail safe configuration. Most were issued in kits, 800-something. The fail-safe opened the B+ to the Horizontal Output Transistor.

The American Radionic and the older CDE ceramic caps (two two-lead ceramic caps) failed open, detuning the flyback, causing the Horizontal drive to increase, increasing the HV to a point of failure.

Only the BLUE ERO/Roederstein and Sprague Orange Drop 4-lead caps were ever used by manufacturers as replacements. Orange EROs exist, and were the early GE replacements, but failed often. Only BLUE EROs were cleared in the GE chassis. Admiral used a multiple cap arrangement, similar to the 22-5001 Zenith .0018uF/1600V caps. Sears went with the Blue EROs (smaller values than the GEs, IIRC) in their sets as replacements - I have one NOS somewhere, but don't expect to find one of the old 528-prefixed Warwick sets.

The American Radionic caps and some Orange ERO 4-lead caps still show up on Fleabay, most in Workman or other discount blister packs. We dumped them at Cain Electronics in the mid-80s, after doing the research with help from Bluefield Distributing (a Zenith Distributor...). I still have one of the gray American Radionic caps, NOS in a Workman package, I merely kept it as a joke.....

[Jon A.]

So, the only thing I can safely replace this with is several orange drops connected parallel, adding up to the original's value? I reckon I can't get a suitable 4-lead orange drop.

[Findm-Keepm]

So yours is bad? It's of the same generation as the Blue EROs, which are the good kind.... that "-4d" is the key. Blue ones are also of the same generation of KP1831 caps:

http://www.ebay.com/itm/1pc-0056MFD-...-/182302985736



What's wrong with another ERO? Saw them for years, no problems. The blue ERO/Roerderstein caps are constructed like the orange drops - they have a failsafe construction - opening up the B+ line to the collector of the HO Transistor. Do a google search by value - somebody probably has one stashed somewhere. I'll look at some of my GE stash - I know I have the two lead variety, but not sure of any 4-lead stuff.

[Findm-Keepm]

0.011uF Sprague, 4-lead:

http://www.ebay.com/itm/SPRAGUE-PP16...YAAOxy6MBSQKOh

The "s11" is the value - a single zero, followed by two ones.

PP=polypropylene
16=1600V
S11=.011uf (S=Single, D=dual, P= none, D11 would be .0011uf, P11 would be .11uF)
S=Critical safety component

[Findm-Keepm]

Turns out, I have 3 different GE Blue ERO caps, 7 in total, all NOS. They are the -4d (4=4-lead, d=generation, the last and best...) They are .0047uf, .0062uf and .0065uf, all pointing to large screen GE sets. One is out of the package, and measures within 60pf of the marked value, after all these years, albeit never under load....

Sorry, no .012uf.

The white and gray baddies:

[zeno]

Theres your answer Jon...... I didnt get msg til last nite.

The Zenith kit is 800-860 . Often on E-bay.
BE VERY CAREFUL TO CHECK THE VALUE !!
The 13" 13GC10 + & the 17" & 19" EFL jugged sets used a different value.
Orange ones did fail. Either shorted popping breaker or opened causing
no HV. Never had one fail with causing too much HV.

Remember the blue ones in Warwick sets but never had a fail.
They were used in that terrible 19" with an RCA bonded yoke set.

Early GE SS sets used a 2 lead white cap behind the HOT.
went left & right. Instant death for the HOT. Change any white ones,
good ones were blue & from Europe IIRC. The white ones would
come apart by pulling on the leads even if still "good".

Maggy same as Zenith. Change any white ones. Sets with
703744-## reg modules also had a shut down. Too much HV would
cause the hoz osc to go way off with narrow pix to prevent disaster.
The symptom is usually the reg board or PC cons.
Other sets with this type SD circuit were RCA, Panny, Hitachi
& probably others. Can be very confusing....

73 Zeno
LFOD !