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. The shape is a circular disk about 1cm in diameter with the following markings - HI-Q 2X .01. Any help greatly appreciate.

wrote:

==========================
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. 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 ?

https://www.ebay.com/itm/Vintage-196...-/123856474984

A pic would be useful.


...... Phil

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

http://printque.us/capacitor.png

On Tuesday, March 2, 2021 at 9:35:21 PM UTC-5, wrote:
wrote:

==========================
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. 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 ?

https://www.ebay.com/itm/Vintage-196...-/123856474984

A pic would be useful.


..... Phil

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

wrote:

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

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

https://www.antiqueradios.com/forums...p?f=8&t=363692

So it's a high voltage, ceramic cap.

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

https://www.mouser.com/ProductDetail...Ocs5KSTQ%3D%3D

Many other sources.


.......... Phil

Phil Allison wrote:
=================
Good replacement would be a 0.01uF, 2kV ceramic like this:

https://www.mouser.com/ProductDetail...Ocs5KSTQ%3D%3D

Many other sources.

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



...... Phil

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 he https://www.allaboutcircuits.com/tec...-y-capacitors/

Mouser-available Vishay-made device he https://www.mouser.com/datasheet/2/4...5r-1762222.pdf

Peter Wieck
Melrose Park, PA

Phil - Appreciate the input and link to Mouser. I've contemplated replacing with a 3-prong cord but 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

On Wednesday, March 3, 2021 at 1:00:06 AM UTC-5, wrote:
Phil Allison wrote:
=================
Good replacement would be a 0.01uF, 2kV ceramic like this:

https://www.mouser.com/ProductDetail...Ocs5KSTQ%3D%3D

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



..... Phil

http://www.antiqueradios.com/forums/...p?f=8&t=363692

https://www.byan-roper.org/steve/_Me...schematic.jpeg

Might help in the restoration process.

On the 2/3 conductor line cord: If you look at the schematic - there are 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. I will not presume that the 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 between the case and the chassis? If so, go ahead and install a 3-wire cord, grounding to the case. If not do some more checks before going to three wires so 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

Peter - Thank you for the explanation, I had a heck of a time looking for this 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 is a picture of the whole thing. This capacitor is run across the the two chokes. Cheers. -Norm

http://printque.us/IMG_5103.jpg


On Wednesday, March 3, 2021 at 8:47:57 AM UTC-5, Peter W. wrote:
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 he https://www.allaboutcircuits.com/tec...-y-capacitors/

Mouser-available Vishay-made device he https://www.mouser.com/datasheet/2/4...5r-1762222.pdf

Peter Wieck
Melrose Park, PA

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: http://www.byan-roper.org/steve/_Med..._5750_med.jpeg
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

You are correct, Peter, that is how the copper cover interacts with the case. There has indeed been several updates to this model, I have 4 different schematics, all similar but slightly different. Of the four, none matches my version perfectly. Thanks again for you input, they've been very helpful. Cheers. -Norm

On Wednesday, March 3, 2021 at 9:48:18 AM UTC-5, Peter W. wrote:
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: http://www.byan-roper.org/steve/_Med..._5750_med.jpeg
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

wrote:

========================
Phil - Appreciate the input and link to Mouser. I've contemplated replacing with a 3-prong cord but
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

Peter ****** Rides Again:

===========================
http://www.antiqueradios.com/forums/...p?f=8&t=363692

https://www.byan-roper.org/steve/_Me...schematic.jpeg

On the 2/3 conductor line cord: If you look at the schematic - there are 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

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

For the sake of accurate info, I mistakenly reported that this capacitor has 2 two legs, upon closer inspection, it has three legs - two outer legs attach to the the chokes and center one attached to the ground terminal of the copper shield that attaches to the signal generator's chassis. Sorry for the earlier misreported response. Cheers. -Norm

On Tuesday, March 2, 2021 at 9:43:50 PM UTC-5, World wide137 wrote:
Thanks Phil. The capacitor has two legs, here's a picture of it. -Norm

http://printque.us/capacitor.png
On Tuesday, March 2, 2021 at 9:35:21 PM UTC-5

==========================
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. 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 ?

https://www.ebay.com/itm/Vintage-196...-/123856474984

A pic would be useful.


..... Phil

Peter ****** is the World's Biggest IDIOT wrote:
-----------------------------------------------------------------------------------
Wrong again.

** Fraid I am dead right again.

Read the schematic. The caps do cross from hot to neutral.

** No they ****ing don't.
Each goes *direct* to chassis ground.

That they are *also* grounded does not change the issue.

** It totally changes the issue of how the cap is connected - ****head.

What happens when/if the ground fails?

** The gene has no safety ground - just a chassis.
That is why I told the OP to fit a 3 wire cord.

Oh, both X and Y capacitors have existed in common use since very roughly 1926,

** Modern X and Y class caps are are different animals.

For decades, Yanks used ordinary DC rated caps for the job in audio gear like guitar amps - now called "death caps".

****ing stupid idea.



...... Phil

wrote:
----------------------------------

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

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

For the sake of accurate info, I mistakenly reported that this capacitor has 2 two legs, upon closer inspection, it has three legs - two outer legs attach to the the chokes and center one attached to the ground terminal of the copper shield that attaches to the signal generator's chassis. Sorry for the earlier misreported response. Cheers. -Norm
On Tuesday, March 2, 2021 at 9:43:50 PM UTC-5, World wide137 wrote:
Thanks Phil. The capacitor has two legs, here's a picture of it. -Norm

http://printque.us/capacitor.png
On Tuesday, March 2, 2021 at 9:35:21 PM UTC-5

==========================
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. 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 ?

https://www.ebay.com/itm/Vintage-196...-/123856474984

A pic would be useful.


..... Phil

Phil - Based on the angle that I looked at it the first time, the center lead was tucked under going to the ground pin on the terminal strip and I missed it. Yes, you were correct with the eBay photo you sent. Cheers. -Norm

On Thursday, March 4, 2021 at 6:33:23 PM UTC-5, wrote:
wrote:
----------------------------------

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

So the one I sent you a pic of *was* RIGHT !!
----------------------------------------------------------------------
For the sake of accurate info, I mistakenly reported that this capacitor has 2 two legs, upon closer inspection, it has three legs - two outer legs attach to the the chokes and center one attached to the ground terminal of the copper shield that attaches to the signal generator's chassis. Sorry for the earlier misreported response. Cheers. -Norm
On Tuesday, March 2, 2021 at 9:43:50 PM UTC-5, World wide137 wrote:
Thanks Phil. The capacitor has two legs, here's a picture of it. -Norm

http://printque.us/capacitor.png
On Tuesday, March 2, 2021 at 9:35:21 PM UTC-5

==========================
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. 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 ?

https://www.ebay.com/itm/Vintage-196...-/123856474984

A pic would be useful.


..... Phil

wrote:

Phil - Based on the angle that I looked at it the first time, the center lead was tucked under going
to the ground pin on the terminal strip and I missed it. Yes, you were correct with the eBay photo you sent.
Cheers. -Norm

** Nice to have that one cleared up finally.

....... Phil

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

https://www.ebay.com/itm/Vintage-196...-/123856474984

A pic would be useful.


..... Phil