Oil filled, mica transmitting capacitors

[N8YX]

Just came across a largish box of these last weekend. Person who has them (XYL of an SK) said to make her an offer that she won't refuse.

Islanders get first crack at them.

I'll get specifics if anyone is interested.

[N4VGB]

Capacitance and ratings rule price.

[N8YX]

Next time I get over that-a-way I'll make some notes.

[kd8dey]

Next time I get over that-a-way I'll make some notes.

I have seen oil filled capacitors used for H.V. power supplies BUT I didn't know they were Mica.

[W1GUH]

How old? Close to expiration?

[N8YX]

I have seen oil filled capacitors used for H.V. power supplies BUT I didn't know they were Mica.
Note the comma.

Both types (oil-filled and mica) are in the box. ;)

[N8YX]

How old? Close to expiration?
Will get that info when I see them next.

[KA5PIU]

Will get that info when I see them next.

Hello.

Unlike electrolytic caps, both Mica and Oil filled can last for years.
Power utilities as well as electric clocks use oil filled capacitors and the life can easily be 70+ years.
The same is true of Mica caps, to a degree.
Mica caps can corrode and change value.
A good cleaning in distilled water in an ultrasonic cleaner will work wonders.
But, it will also frequently clean off any printed markings!

[N4VGB]

Hello.

Unlike electrolytic caps, both Mica and Oil filled can last for years.
Power utilities as well as electric clocks use oil filled capacitors and the life can easily be 70+ years.
The same is true of Mica caps, to a degree.
Mica caps can corrode and change value.
A good cleaning in distilled water in an ultrasonic cleaner will work wonders.
But, it will also frequently clean off any printed markings!

I dunno what we'd do without you.

[NQ6U]

I dunno what we'd do without you.

Me either, but I'd like to find out...

[PA5COR]

^ Snark :lol:

[ab1ga]

Nah, we gotta keep Rudi. His posts run from unnerving to irritating to humorous to downright inspired.
(Full disclosure: I admit to looking at surplus APUs as the power system for a homebrew hybrid car. Too big for my taste.)

[n2ize]

Will get that info when I see them next.

If they are PCB filled they'll last a lifetime :)

[WØTKX]

In ya liva! ;)

[W1GUH]

If they are PCB filled they'll last a lifetime :)

And provide you and yours some extra nutrition.

But seriously, there was a recent thread somewhere else about oil-filled caps definitely having a shelf life, but I forget the particulars & don't have the stomach to go back there to check out the story. Just sayin'

[n2ize]

And provide you and yours some extra nutrition.

But seriously, there was a recent thread somewhere else about oil-filled caps definitely having a shelf life, but I forget the particulars & don't have the stomach to go back there to check out the story. Just sayin'

Well, I have several oil filled caps laying around here, many of the PCB filled variety and some of the non-PCB filled variety, many dating back to the 1940's. Any time I've picked one off the shelf and put it into a circuit it worked perfectly and was still well within its rated specs.So, if there is a shelf life I have never noticed it. As long as they aren't leaking they seem to be good.

[n2ize]

Just came across a largish box of these last weekend. Person who has them (XYL of an SK) said to make her an offer that she won't refuse.

Islanders get first crack at them.

I'll get specifics if anyone is interested.

Are you sure they are oil filled ? Reason I ask is that there are some large rectangular transmitting caps that resemble oils but they actually use a non-oil dielectric inside.

[N5RLR]

FWIW, I've read that mica caps can be problematic in some cases, as mentioned here. [click] (http://amfone.net/Amforum/index.php?topic=18534.msg198772#msg198772) YMMV.

Also, oil-filled [PCB- and non] caps should be okay provided they're not bulging, dented, leaking, or otherwise damaged/abused. Best to check with a capacitance meter before putting serious voltage to them.

[KA5PIU]

Hello.

Read that article carefully.
It indicates that most of the higher value and higher voltage units were fine.
That is to be expected, as hams are very much noted for taking a component that is rated for receiving and placing it in transmitting service.
Also, I stated 70 years as prior to that it was not uncommon to use acid solder.
And, yes, a transformer filled with pcb's is far more stable than one without.
http://en.wikipedia.org/wiki/Polychlorinated_biphenyl
Our power transformer is 70+ years old and still works just fine.
It has lead paint and was refilled in the 70's with pcb and repainted when the pole was replaced.
It is of the very old multi primary tap type as well as the super deluxe 117/234 secondary.
In its era, the customer bought the transformer as well as the meter and even had to pay for the pole.

[KX5JT]

Any news on this caps yet?

[N8YX]

Any news on this caps yet?
Not yet - I'll try to get over to my friend's place sometime in the next week or two.

[N8YX]

Here's the list:

Sangamo, GE 4, 6, 8, 10uF, 600WVDC oil-filled - a couple (low values) to 5 (high values) of each.

Assorted .05/.1/.25 uF, 600/1000 WVDC oil-filled - a couple of each

.0001uF, 1KV mica transmitting caps - 1
.001/4.5KV, .006/2.5KV mica transmitting caps - one each
.01uF, 250V mica transmitting caps - 1
.02uF, 1KV mica transmitting caps - 1
.0005uF 2.5KV mica transmitting caps - 8
.01uF, 1KV mica transmitting caps - 1
.02uF, 2.5KV mica transmitting caps - 1

Brackets for the larger oil-filled caps - 16

The box weighs around 25lbs.

Make me an offer for the lot which I won't refuse. These are from the estate of a buddy of mine and all proceeds go to benefit his widow, who is also a ham.