Ancient electrical connector

[karn]

I found this old RV electrical tester. It appears to be missing the power cord, and the casing is riveted. Has anyone seen this style of connector/plug before? I was hoping to find out if it's 12-volt or 120-volt and if it's polarity-sensitive.

 

[synchro]

It looks like a polarized two-wire 120VAC inlet to me. You should be able to find a two-wire extension cord that fits.
Now that does not guarantee that they used this connector for 120V. I remember in grade school they had a movie projector where the speakers used standard two-prong 120VAC plugs, and so some student plugged them into the wall with a dramatic effect.

 

[karn]

Yeah, I was assuming 120v, I might just have to drill out the rivets and take a look inside. I've been curious to peek at the electronics anyway.

 

[Frank DuVal]

That is NOT a 120 volt connector!

It is a two prong Cinch -Jones connector which we commonly use for vehicle voltage (typically 12 volts in the 60/70s). I used many of these is installing amatuer radio equipment into cars..

Now, whether the wide prong is + or - depends on who built the box. If one prong reads 0 ohms to case, pretty good assumption that is the - terminal, since there were very few (1956 Packard only typically for domestics, MG took longer to change) positive ground 12 volt vehicles.

And not ancient! Still in production.

Jones Plugs | Cinch Connectivity Solutions

The 300 and 2400 Series Cinch Jones Plugs have been utilized for decdes and provide a quick reliable and economical means of solving higher current-carrying capcity needs.

www.belfuse.com

 

[karn]

Thanks for the info, I couldn't get a reading to the case but the smaller prong reads 3.5 ohms to the ground terminal on the 7-way port.

 

[GoldDigger]

They were also commonly used for loudspeaker connections before the 1/4" phone plug became the standard
They were subject to surface corrosion, especially when used outdoors, requiring an occasional application of WD-40 by amateurs and a deoxidizer by professionals.
As shown in Frank's link they are available is higher numbers of conductors too. All of them are polarized.