I'm starting my first refurbishment of an old receiver.

Even before I power up I want to replace the electrolytics based on age
degradation principles. [I'm a retired EE and understand age degradation in 40+
year old capacitors]].

Being away from parts suppliers for 10+ years leaves me ignorant of what is
where. Therefore my original question: "What is a good source for electrolytics?"]

/S/ DD, W1MCE

Dave, You have some choices. Antique Electronic Supply and Surplus
Sales of Nebraska both offer said-to-be-new can-type electrolytics at
very high (relatively speaking) prices. If below the chassis esthetics
are of less importance, leave the cans in place and wire around them
using an appropriate value replacement, one typical brand being
axial-lead XICONs. Mouser has the best price on these. Also available
are "snap-in" type computer caps. No leads on these, of course, just
tabs. The third possibility is to remove the offending can capacitor,
gut it and re-stuff with one of the new, smaller types. Personally, I
below chassis wire in XICONs. But, it all depends on what your pleasure
is. de Jeep/K3HVG

Dave wrote:
I'm starting my first refurbishment of an old receiver.

Even before I power up I want to replace the electrolytics based on age
degradation principles. [I'm a retired EE and understand age degradation
in 40+ year old capacitors]].

Being away from parts suppliers for 10+ years leaves me ignorant of what
is where. Therefore my original question: "What is a good source for
electrolytics?"]

/S/ DD, W1MCE

Dave wrote:
I'm starting my first refurbishment of an old receiver.

Even before I power up I want to replace the electrolytics based on age
degradation principles. [I'm a retired EE and understand age degradation
in 40+ year old capacitors]].

Before you go to the trouble of replacing the electrolytics, you really ought
to reform them. If they are still moist inside, they will usually reform to
like new characteristics... If you don't first ruin them by turning the radio
on.

To reform, you need a DC supply at the WV rating of the capacitor, and a 2K
5W series resistor to limit current. If your supply has a roll back current
limit pot, you can set that to a few tens of milliamps instead. It usually
only takes a half hour to reform a cap. You can tell how you are doing by
what happens with the current. The current should drop to near zero.

-Chuck

Dave wrote:

Even before I power up I want to replace the electrolytics based on age
degradation principles. [I'm a retired EE and understand age degradation in 40+
year old capacitors]].

Being away from parts suppliers for 10+ years leaves me ignorant of what is
where. Therefore my original question: "What is a good source for electrolytics?"]

Digi-Key, Mouser, and when you absolutely need can caps, Antique Electronics
Supply. A phone call to 1-800-DIGI-KEY for a catalogue will be an eye-opener
if you remember what their catalogue was like ten years ago. These days it's
bigger than Newark or Allied.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Dave wrote:
I'm starting my first refurbishment of an old receiver.

Even before I power up I want to replace the electrolytics based on age
degradation principles. [I'm a retired EE and understand age degradation
in 40+ year old capacitors]].

Being away from parts suppliers for 10+ years leaves me ignorant of what
is where. Therefore my original question: "What is a good source for
electrolytics?"]

/S/ DD, W1MCE


Hi Dave,

If you don't find what you need surplus, www.jameco.com has better
prices on most than www.mouser.com A couple others to compare with
would be www.alliedelec.com or www.newark.com .

I often find what I need from some of the places that buy excess
inventory from manufacturers but do watch their prices. Sometimes they
are more expensive than just ordering new. You can check out
www.allelectronics.com www.alltronics.com or www.mpja.com

Good luck on your project!

Paul
WD8OSU

TOP POSTED ... UGH! But pls forgive me.

TU for the 4 replies. Gets me going in a good direction.

/s/ DD, W1MCE

Dave wrote:

I'm starting my first refurbishment of an old receiver.

Even before I power up I want to replace the electrolytics based on age
degradation principles. [I'm a retired EE and understand age degradation
in 40+ year old capacitors]].

Being away from parts suppliers for 10+ years leaves me ignorant of what
is where. Therefore my original question: "What is a good source for
electrolytics?"]

/S/ DD, W1MCE

People can honestly disagree about reforming, but personally I have had poor
luck with it. Some caps will reform, but I found that they were not reliable
for the long haul.

Why risk frying an expensive power transformer just to save a few bucks
worth of electrolytics?

Phil Nelson

Phil Nelson wrote:
People can honestly disagree about reforming, but personally I have had poor
luck with it. Some caps will reform, but I found that they were not reliable
for the long haul.

Why risk frying an expensive power transformer just to save a few bucks
worth of electrolytics?

Why risk frying an expensive power transformer by turning on an antique
radio?

If you reform the caps the way I said to, you will know before you finish
if the cap is going to be good for the long haul. I have never had one
fail that correctly went through a reformation.

That said, I have lost electrolytics when I have tried the trick of using
a variac to "reform" the whole power supply before applying full mains
voltage. I am quite sure that most of them would have reformed correctly
if I hadn't skimped on the process.

-Chuck

"Chuck Harris" wrote in message
...
Phil Nelson wrote:
People can honestly disagree about reforming, but personally I have had
poor luck with it. Some caps will reform, but I found that they were not
reliable for the long haul.

Why risk frying an expensive power transformer just to save a few bucks
worth of electrolytics?

Why risk frying an expensive power transformer by turning on an antique
radio?

If you reform the caps the way I said to, you will know before you finish
if the cap is going to be good for the long haul. I have never had one
fail that correctly went through a reformation.

That said, I have lost electrolytics when I have tried the trick of using
a variac to "reform" the whole power supply before applying full mains
voltage. I am quite sure that most of them would have reformed correctly
if I hadn't skimped on the process.

-Chuck

If I'm going to go to all the trouble to remove a cap I'm going to replace
it not play patty cake with it and take chances

--

Clif Holland KA5IPF
www.avvid.com

Clif Holland wrote:
"Chuck Harris" wrote in message


That said, I have lost electrolytics when I have tried the trick of using
a variac to "reform" the whole power supply before applying full mains
voltage. I am quite sure that most of them would have reformed correctly
if I hadn't skimped on the process.

-Chuck

If I'm going to go to all the trouble to remove a cap I'm going to replace
it not play patty cake with it and take chances


Why would you remove the cap to reform it?

On tube circuits, you can do the job in place, just don't fire
up the filaments.

The important point to reforming is that you don't supply buckets of
current to the subject capacitor. If you do, the capacitor will create
little localized hot-spots where the oxide is too thin.

-Chuck