Need Help Identifying Ceramic Capacitor

Hello Folks. I need some help in identifying a ceramic capacitor on an RF signal generator from the 50's. The capacitor is off the power supply. Th e shape is a circular disk about 1cm in diameter with the following marking s - HI-Q 2X .01. Any help greatly appreciate.

Reply to
World wide137
Loading thread data ...

==========================

The capacitor is off the power supply. The shape is a circular disk about 1cm in diameter with the following markings - HI-Q 2X .01.

** Is is dual cap with 3 legs like this one ?

formatting link

A pic would be useful.

..... Phil

Reply to
Phil Allison

Thanks Phil. The capacitor has two legs, here's a picture of it. -Norm

http://pr> snipped-for-privacy@gmail.com wrote:

Reply to
World wide137

I should mention that this capacitor is in a Precision signal generator, model E-200-C.

Reply to
World wide137

=================================

That cap is in the AC supply circuit - right? See bottom of this page:

formatting link

So it's a high voltage, ceramic cap.

Good replacement would be a 0.01uF, 2kV ceramic like this:

formatting link

Many other sources.

......... Phil

Reply to
Phil Allison

Phil Allison wrote: =================

** Be nice idea to fit a 3- core power lead and earth the thing while you are at it.

..... Phil

Reply to
Phil Allison

That looks very much like an older ceramic safety capacitor. 2X today would be written as X2. That being "X-type, Ceramic Class 2". Their purpose is to minimize EMI/RFI interference - something that makes sense in an SG.

The X means that it is to go between the line-cord leads (hot and neutral). 2X means it will tolerate a peak voltage pulse of 2,500 while in operation.

More explanation here:

formatting link

Mouser-available Vishay-made device here:

formatting link

Peter Wieck Melrose Park, PA

Reply to
Peter W.

QlHqqfWLOcs5KSTQ%3D%3D

are at it.

Reply to
World wide137

formatting link

formatting link

Might help in the restoration process.

On the 2/3 conductor line cord: If you look at the schematic - there are t wo (2) 0.01uF safety caps in series with a ground between them - which is t he same common ground throughout the system. And, by the way, those are X-t ypes as the are between the hot and the neutral. I will not presume that t he common ground is also the case even though that is both very likely and common, but you can check that easily yourself - is there continuity betwee n the case and the chassis? If so, go ahead and install a 3-wire cord, grou nding to the case. If not do some more checks before going to three wires s o that you do not cause any damage. Also, when the device is in operation, is there any leakage (VOM on AC, case-to-good-ground: Any voltage showing?) ?

Peter Wieck Melrose Park, PA

Reply to
Peter W.

Peter - Thank you for the explanation, I had a heck of a time looking for t his on Google. I guess, I wasn't sure on how to search for it. Searching for what was printed on the actual capacitor did not bring up much. Here i s a picture of the whole thing. This capacitor is run across the the two c hokes. Cheers. -Norm

formatting link

ld be written as X2. That being "X-type, Ceramic Class 2". Their purpose is to minimize EMI/RFI interference - something that makes sense in an SG.

). 2X means it will tolerate a peak voltage pulse of 2,500 while in operati on.

Reply to
World wide137

Norm:

A few things:

a) There are many versions of this unit over the years, so the differences between the schematic and what you have are no surprise. b) There is no reason to remove the tubular ceramic caps - I believe that the restoration page does mention that. They tend to be pretty stable over the years. c) I would restore to the schematic as shown:

formatting link
d) I see where the ground lug is riveted to the copper cover - and that the cover appears to be sheet-metal-screwed to the case. If so, a 3-wire cord is good, with the ground wire going to the center lug of the three.

Take your time. That is a 'popular' unit within the hobby, and worth the effort if you want vintage service gear to go with the vintage radios.

Peter Wieck Melrose Park, PA

Reply to
Peter W.

s between the schematic and what you have are no surprise.

the restoration page does mention that. They tend to be pretty stable over the years.

he cover appears to be sheet-metal-screwed to the case. If so, a 3-wire cor d is good, with the ground wire going to the center lug of the three.

effort if you want vintage service gear to go with the vintage radios.

Reply to
World wide137

========================

there seems to be some who say a two prong is better for a sound generator as to not pick up any interference off the ground from other devices. I'm a hobbyist so my depth of knowledge isn't so deep as to accept or refute their claims so I've just left it for now. Cheers. -Norm

----------------------------------------------------------------------------------------

** Warning:

The case of the unit will be floating at * 60volts AC* with no safety ground attached.

That AC voltage ( with plenty of noise) will be coupled via 0.02 uF into the ground of any earthed reciever. Likely make it hum and buzz audibly.

Your RF gene has only a 400Hz output for convenience.

Earthing it is way safer.

...... Phil

Reply to
Phil Allison

Peter Wanker Rides Again:

========================= ==

two (2) 0.01uF safety caps in series with a ground between them - which is the same common ground throughout the system. And, by the way, those are X- types as the are between the hot and the neutral.

** Weicky has wanked himself blind.

Those two cap are *OBVIOUSLY* connected from hot AC wires to ground.

Y class caps with not common back in the day.

...... Phil

Reply to
Phil Allison

Wrong again. Once more the drongo from down under, the official village idiot of this venue has outdone itself.

Read the schematic. The caps do cross from hot to neutral. That they are *also* grounded does not change the issue. What happens when/if the ground fails?

Oh, both X and Y capacitors have existed in common use since very roughly 1926, with research in ceramic materials starting in the mid-teens, perfected in the very early 1920s. I know that Australia is a technical wasteland, but really!

Peter Wieck Melrose Park, PA

Reply to
Peter W.

===

n RF signal generator from the 50's.

ut 1cm in diameter with the following

Reply to
World wide137

----------------------------------

** How come the third lead is *missing* in your pic?

So the one I sent you a pic of *was* RIGHT !!

----------------------------------------------------------------------

has 2 two legs, up> > Thanks Phil. The capacitor has two legs, here's a picture of it. -Norm

===

an RF signal generator from the 50's.

bout 1cm in diameter with the following

Reply to
Phil Allison

r has 2 two legs, up> > > Thanks Phil. The capacitor has two legs, here's a picture of it. -Nor

m

====

on an RF signal generator from the 50's.

about 1cm in diameter with the following

Reply to
World wide137

** Nice to have that one cleared up finally. ...... Phil

Reply to
Phil Allison

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.