Jump to content

GPO panel mount socket


richard

Recommended Posts

An 'A' gauge jack is a common 1/4" jack plug, sort of thing you might find on a guitar lead or a pair of headphones. A 'B' gauge plug has the same diameter but has a smaller tip; also known as Post Office jacks or GPO jacks. Historically used in old fashioned manual telephone exchanges, they became extensively used in broadcast and recording environments.
Link to comment
Share on other sites

If I remember correctly, the "A-gauge" is pretty much a standard 1/4" TRS jack. "B-gauge" has a deeper "notch" at the tip, and the ring is a slightly different length.

 

Sticking a standard plug into a B-type socket is not a good idea, as it can damage the contacts.

Link to comment
Share on other sites

If I remember correctly, the 'A-gauge' is pretty much a standard 1/4" TRS jack. 'B-gauge' has a deeper 'notch' at the tip, and the ring is a slightly different length.

Sticking a standard plug into a B-type socket is not a good idea, as it can damage the contacts.

 

You have it about right except I would be careful with using the term 'standard'. The origin of the word 'jack' means socket, ie you would have a plug and jack. and the original is in fact the 'B gauge'. The cheaper and lower quality 'A gauge' was introduced much later as a 2 pole version (now described as mono). Describing a plug as 'standard' will vary between the styles depending on the industry.

 

As an aside the original jack was not a hole which the plug was inserted through, it was a series of open contacts which the plug was hooked onto.

 

I just about remember dad's first amplifier in the 50's, it had a B-gauge for the balanced mic I/p and what was effectively a pair of 2mm banana plugs spaced about 3/4" for the gram I/p. The (still existing and occasionally used) speakers have the same connector on the side.

 

I was told many years ago the non PO version was originally made by a company called Gage which gave rise to the phrase 'a Gage plug' in the same way one would say: 'a Rayrolle plug'. I truly don't know if there is any truth in it, I have my suspicions it was one of those old wives tales that abound all industries. (Like the term 81's). But Hoover did manufacture the first vacuum cleaner and singer...

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.