Erie Ceramic Capacitor Information - UK Vintage Radio Repair and Restoration Discussion Forum

jonnybear · 8th Dec 2015, 11:36 am

Can anyone help, I have a few Erie 4700 M AL ceramic capacitors, I presume 4700 is 4700pf, I am unable to find the voltage rating, assume M AL must mean something. They are 13mm in diameter so quite large.
Many thanks
John

ronbryan · 8th Dec 2015, 12:30 pm

The ITT Electronic Services Yellow book specifies AL as K2600 dielectric, which is a high permittivity (Hi-K) dielectric. No hint of the working voltage though. M is +/- 20% tolerance.

A lot of old stock Hi-K ceramics read low when the capacitance is tested on a bridge.

They might be style 811 (15mm diameter in the catalogue), which are 500V dc rated

Ron

FrankB · 11th Dec 2015, 3:30 am

500 WVDC ceramics.
I have drawers full of them here.
They didn't start reducing the voltage till, IIRC, mid 60's for the transistor radios, and even then they often used 500 WVDC caps in them.

jonnybear · 11th Dec 2015, 9:53 am

Thank you both Ron & Frank for your replies, 500v will make them very useful, it seems that a lot of capacitors when purchased commercially from manufacturers of equipment, have little or no markings, making it difficult when they come on to the surplus market to know there working voltages and values, though values can be easily read with a capacitance meter, working voltages is a different mater.
John

8th Dec 2015, 11:36 am	#1
jonnybear Octode Join Date: Nov 2010 Location: Cullompton, Devon, UK. Posts: 1,435	Erie Ceramic Capacitor Information Can anyone help, I have a few Erie 4700 M AL ceramic capacitors, I presume 4700 is 4700pf, I am unable to find the voltage rating, assume M AL must mean something. They are 13mm in diameter so quite large. Many thanks John Attached Thumbnails

8th Dec 2015, 12:30 pm	#2
ronbryan Octode Join Date: Jan 2003 Location: Guildford, Surrey, UK. Posts: 1,959	Re: Erie Ceramic Capacitor Information The ITT Electronic Services Yellow book specifies AL as K2600 dielectric, which is a high permittivity (Hi-K) dielectric. No hint of the working voltage though. M is +/- 20% tolerance. A lot of old stock Hi-K ceramics read low when the capacitance is tested on a bridge. They might be style 811 (15mm diameter in the catalogue), which are 500V dc rated Ron Last edited by ronbryan; 8th Dec 2015 at 12:57 pm.

11th Dec 2015, 3:30 am	#3
FrankB Heptode Join Date: Oct 2005 Location: Olympia, Washington, USA. Posts: 664	Re: Erie Ceramic Capacitor Information 500 WVDC ceramics. I have drawers full of them here. They didn't start reducing the voltage till, IIRC, mid 60's for the transistor radios, and even then they often used 500 WVDC caps in them.

11th Dec 2015, 9:53 am	#4
jonnybear Octode Join Date: Nov 2010 Location: Cullompton, Devon, UK. Posts: 1,435	Re: Erie Ceramic Capacitor Information Thank you both Ron & Frank for your replies, 500v will make them very useful, it seems that a lot of capacitors when purchased commercially from manufacturers of equipment, have little or no markings, making it difficult when they come on to the surplus market to know there working voltages and values, though values can be easily read with a capacitance meter, working voltages is a different mater. John