Tubular Blue "Molded" Capacitors - Who made them? [Updated w/reply from Fender]

mabinogeon

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Hi all,

This is another one of those questions that doesn't really matter, but I'm curious anyway.

I've heard the tubular blue molded caps in '60s Fender amps variously referred to as "Ajax", "Mallory", and "Sprague", but I just stumbled across a couple NOS .1µF 1000V caps that are labeled Packard-Bell.


The top two .047µF caps in that picture are the ground switch caps out of two '60s Fender amps I own.

Does anyone happen to have a definitive answer on this? Did Packard Bell manufacture their own components for use in their radios and TVs and computers back then? Or were these made by someone else and rebranded Packard Bell (that is my assumption)? Is there a datasheet for these floating around out there somewhere?

Thanks! :)
 

VICOwner

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I’m pretty sure they are called Astron blue caps. They are supposed to be the cream of the crop for fender amps.
 

mabinogeon

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Was it Astron?

Someone elsewhere suggested these might be two different types of capacitor, but I think they’re the same.

Here's another picture of the capacitors I have, this time of the ends:

They look pretty similar to me: same paper label, same color casing, same bump on the outer foil-side endcap.

Regarding the Astrons: I can't find where they ever made a 1000V cap, one in blue, and the construction appears different based on what I'm seeing on ebay. But who knows what was going on 50+ years ago...

It looks like some ""Molded" caps have square-ish ends and some have the more familiar rounded ends. Perhaps this is due to capacitance and voltage? here's a "Molded" .022uF 200V with square ends, and here is a .022uF 200V with rounded ends.

And here's a pair, one with a "Molded" label and one with a Packard-Bell label.

Perhaps we've been dealing with two different types of capacitors all along and just didn't know it? Nah

Perhaps we'll never know for sure?

Thanks again :)
 

Jeff Gehring

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My understanding is that Ajax was the maker, but I really don't know, either. It's curious that the mold shapes vary so much, from the hemispherical ends you see in most BF Fenders to completely squared off ends, like the 0.01uF caps shown here:

index.php
 

mabinogeon

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I'm fairly sure the "Blue Molded" ones are Ajax.
My understanding is that Ajax was the maker,
I’ve always heard them called Ajax, too.
I'd love to be able to find a datasheet for these.

Did they print datasheets for this sort of thing back then? Maybe there's one tucked away in the back of a dusty file cabinet at Fender HQ :)

I know tubes from that era have datasheets, but I've never seen a 50-year-old resistor or capacitor datasheet.
 

HotBluePlates

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I have no idea about the maker of Fender's blue molded caps. I've read "Ajax" and I've read "Mallory." I've yet to see any advertising or catalog stuff from the 60s that matches them (though many companies were figuring out plastic dielectric and molded construction were good things).

The yellow Astron caps were called "Astron Blue-Point" because there was a little blue dot visible where the lead exited the body of the cap.

NOS-Astron-005-uf-600v-Mustard-Capacitor-Guitar.jpg

Unfortunately, they leak as they get older. A guy that has actually cut some open says they're paper dielectric (explains the eventual leaking), until some point when there was a paper/plastic hybrid dielectric.

Found this last night:

 

mabinogeon

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That's a very interesting site. I think I will email him this evening.

On the very bottom of the page, he says he is looking for info on the "Mallory "blue molded" caps, as used in Fender amplifiers and some Conn and Thomas organs, among others (they hold up very well, and are probably plastic-film)." Mallory isn't Ajax, so back to square one :D
 
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mabinogeon

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Just for fun I did some digging.

Some but not all blue Molded caps, whether they have the paper labels, the yellow text, or are branded Packard-Bell, are stamped MC1 followed by a date code. So I think from that we can surmise they are all the same type of capacitor from the same manufacturer, but we're still no closer to confirming who that manufacturer was:


I assume the "MC" stands for Molded (or perhaps Mylar) Capacitor.

(photos taken from ebay listings)
 
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HotBluePlates

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... "Mallory "blue molded" caps ... Mallory isn't Ajax, so back to square one :D
... stamped MC1 ...

"Ajax" could be a trade-name for a model of capacitor, like "Atom."

worldradiohistory.com has books, magazine, trade publications, and catalogs from the 30's through the 70's. I haven't gone through much of it, but when I saw catalog-style lists of Mallory caps I did not see "MC1" nor any reference to blue molded caps.

That doesn't mean they're not out there. But documentation seems thin on the ground.
 

mabinogeon

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"Ajax" could be a trade-name for a model of capacitor, like "Atom."

worldradiohistory.com has books, magazine, trade publications, and catalogs from the 30's through the 70's. I haven't gone through much of it, but when I saw catalog-style lists of Mallory caps I did not see "MC1" nor any reference to blue molded caps.

That doesn't mean they're not out there. But documentation seems thin on the ground.
That's a cool site, and I hadn't ever heard of it until your previous post. I will spend some time perusing it after my kiddos get to bed tonight. Thanks!

A point of interest: all the yellow-labeled caps I've seen have a date code of 1967, but I've seen some paper-labeled ones dated 1968. Admittedly, a few dozen eBay listings is a very small sample size.

Makes me wonder if the yellow-labels weren't well received, so they went back to the paper labels.
 
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mabinogeon

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It appears as though Ajax also made a ceramic-shell mylar cap during this era, the 705 series, which was actually labeled as Ajax:

 

VICOwner

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Yep, I looked around too. Ajax blue, Mallory blue. The Astron I referred to earlier was my mistake. What I’m pretty sure about though is that they are the ones to put in a Fender.
 

Kyle B

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I know who made them. It was Frank McMority and Jacob Farnzwell. They were the two managers who ran that cap line back in the 60's.

Frank and Jacob were both WWII Navy vets, Frank having served aboard the USS Condensor and Jacob on the USS Coulomb. Frank passed away in 2004 in Mylar Springs, Florida, while Jacob is still with us - Living at the St. Flux nursing home in Cleveland, Ohio.

Although sadly, as of late Jacob is showing some signs of dementia - He thinks his name is "Henry"


I thought everybody knew this stuff. Geez - And you guys are "experts"....
 




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