What is it? (component)

[Ivan Vegvary]

Size and shape is identical to a 1/4 watt carbon axial lead resistor.

Body is glass-like and has a red band on each end.

Markings are: 104M - - 50V - - WC - - 8421

Analog ohm meter reads infinity but slowly drops to about 5 meg in about 10 seconds time. Readings in both directions are identical.

Thanks for the help,
Ivan Vegvary

 

[Phil Allison]

"Ivan Vegvary"

Size and shape is identical to a 1/4 watt carbon axial lead resistor.

Body is glass-like and has a red band on each end.

Markings are: 104M - - 50V - - WC - - 8421

** Class encapsulated, ceramic capacitor.

100nF, 20% tolerance 50V rating - made in the 21st week of 1984.

Likely manufactured by Unitrode.

Old Peavey guitar amps were full of them - easily mistaken for zener
diodes.



..... Phil

 

[Michael Black]

On Sun, 11 Nov 2012, Phil Allison wrote:

"Ivan Vegvary"

Size and shape is identical to a 1/4 watt carbon axial lead resistor.

Body is glass-like and has a red band on each end.

Markings are: 104M - - 50V - - WC - - 8421


** Class encapsulated, ceramic capacitor.

100nF, 20% tolerance 50V rating - made in the 21st week of 1984.

Yes, the giveaway was the "104".

Michael

Likely manufactured by Unitrode.

Old Peavey guitar amps were full of them - easily mistaken for zener
diodes.



.... Phil

 

[Phil Allison]

"Michael Black"

Yes, the giveaway was the "104".

** Must be one of them rocket scientist types ....





..... Phil

 

[Tim Wescott]

On Sat, 10 Nov 2012 21:18:21 -0800, Ivan Vegvary wrote:

Size and shape is identical to a 1/4 watt carbon axial lead resistor.

Body is glass-like and has a red band on each end.

Markings are: 104M - - 50V - - WC - - 8421

Analog ohm meter reads infinity but slowly drops to about 5 meg in about
10 seconds time. Readings in both directions are identical.

Thanks for the help,
Ivan Vegvary

Like Phil said, its a 100nF cap.

What I want to know, though, is why the meter starts at infinity then
drops to 5 megohm -- I would think it'd stay at infinity.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

 

[Michael Black]

On Mon, 12 Nov 2012, Tim Wescott wrote:

On Sat, 10 Nov 2012 21:18:21 -0800, Ivan Vegvary wrote:

Size and shape is identical to a 1/4 watt carbon axial lead resistor.

Body is glass-like and has a red band on each end.

Markings are: 104M - - 50V - - WC - - 8421

Analog ohm meter reads infinity but slowly drops to about 5 meg in about
10 seconds time. Readings in both directions are identical.

Thanks for the help,
Ivan Vegvary

Like Phil said, its a 100nF cap.

What I want to know, though, is why the meter starts at infinity then
drops to 5 megohm -- I would think it'd stay at infinity.

Somebody's fingers are holding the test leads against the capacitor leads

and increased pressure causes the reading to drop?

Michael

 

[amdx]

On 11/12/2012 9:30 AM, Tim Wescott wrote:

On Sat, 10 Nov 2012 21:18:21 -0800, Ivan Vegvary wrote:

Size and shape is identical to a 1/4 watt carbon axial lead resistor.

Body is glass-like and has a red band on each end.

Markings are: 104M - - 50V - - WC - - 8421

Analog ohm meter reads infinity but slowly drops to about 5 meg in about
10 seconds time. Readings in both directions are identical.

Thanks for the help,
Ivan Vegvary

Like Phil said, its a 100nF cap.

What I want to know, though, is why the meter starts at infinity then
drops to 5 megohm -- I would think it'd stay at infinity.

Cause the cap was charged in one direction, then the leads were swapped

and the meter reads infinity until until the charge polarity changes and
then it measures leakage resistance.
Until someone tells me better.
Mikek

 

[Michael Black]

On Mon, 12 Nov 2012, amdx wrote:

On 11/12/2012 9:30 AM, Tim Wescott wrote:
On Sat, 10 Nov 2012 21:18:21 -0800, Ivan Vegvary wrote:

Size and shape is identical to a 1/4 watt carbon axial lead resistor.

Body is glass-like and has a red band on each end.

Markings are: 104M - - 50V - - WC - - 8421

Analog ohm meter reads infinity but slowly drops to about 5 meg in about
10 seconds time. Readings in both directions are identical.

Thanks for the help,
Ivan Vegvary

Like Phil said, its a 100nF cap.

What I want to know, though, is why the meter starts at infinity then
drops to 5 megohm -- I would think it'd stay at infinity.

Cause the cap was charged in one direction, then the leads were swapped and
the meter reads infinity until until the charge polarity changes and then it
measures leakage resistance.
Until someone tells me better.

Except, it's a .1uF capacitor, not really going to hold a charge

Michael

 

On Mon, 12 Nov 2012 15:49:05 -0500, Michael Black <et472@ncf.ca>
wrote:

On Mon, 12 Nov 2012, amdx wrote:

On 11/12/2012 9:30 AM, Tim Wescott wrote:
On Sat, 10 Nov 2012 21:18:21 -0800, Ivan Vegvary wrote:

Size and shape is identical to a 1/4 watt carbon axial lead resistor.

Body is glass-like and has a red band on each end.

Markings are: 104M - - 50V - - WC - - 8421

Analog ohm meter reads infinity but slowly drops to about 5 meg in about
10 seconds time. Readings in both directions are identical.

Thanks for the help,
Ivan Vegvary

Like Phil said, its a 100nF cap.

What I want to know, though, is why the meter starts at infinity then
drops to 5 megohm -- I would think it'd stay at infinity.

Cause the cap was charged in one direction, then the leads were swapped and
the meter reads infinity until until the charge polarity changes and then it
measures leakage resistance.
Until someone tells me better.

Except, it's a .1uF capacitor, not really going to hold a charge

Compared to the input resistance of the meter? What's going to
discharge it?