What is the purpose of this outlet? - Page 1
Forum section: electronics / projects

author: TheMetal123
author_rank: Newbie
timestamp: September 21, 2021, 04:07:39 am
content: I joined this forum to ask what the purpose of this outlet (see attached) is. I've found it in my room after moving around some furniture, and I don't really see what it could be used for. After searching (including reverse image searching), I could only find that it is apparently a "Despard" outlet covering. If any of you could help me understand what this is and what it is used for, it would be much appreciated. Thanks.

author: james_s
author_rank: Super Contributor
timestamp: September 21, 2021, 04:26:16 am
content: Looks late 50s-mid 60s from the design of the plate. Maybe a phone jack? I've seen some old ones that were 4 pins, I don't recall ever seeing a 3 pin one like that. Can you remove the plate and see what kind of wires are attached?

author: floobydust
author_rank: Super Contributor
timestamp: September 21, 2021, 04:56:32 am
content: I remember those as TV antenna (rooftop) connector, for 300 ohm twinax. Can't remember the third pin if it was for 75 ohm out or ground or a second antenna i.e. VHF.

author: WattsThat
author_rank: Frequent Contributor
timestamp: September 21, 2021, 05:02:11 am
content: Yup, 300 ohm flat lead antenna connector. Maybe Jerrold brand.

author: metertech58761
author_rank: Frequent Contributor
timestamp: September 21, 2021, 05:52:48 am
content: Haven't seen those around in years and even back when I was a kid, they weren't common. Definitely an outlet for the old aerial 300-ohm TV antenna cable (versus snaking the cable in under a window).

author: EPAIII
author_rank: Super Contributor
timestamp: September 21, 2021, 07:41:25 am
content: Building a bit on the other answers, they do make shielded 300 Ohm twin lead. That third, center hole is probably a ground/shield connection.

author: Nusa
author_rank: Super Contributor
timestamp: September 21, 2021, 08:23:55 am
content: Quote from: TheMetal123 on September 21, 2021, 04:07:39 amYes, that was used as a TV-FM connector way back. If you remove the two screws and the wall plate, you should find a 3-gang bracket with a module in the center bracket, probably attached to a metal wall box. Odds are you'll be able to eyeball the 300 ohm twin-lead without any further disassembly. If you have an antique roof antenna still, it might even be connected to it. Knowing the age of the house is relevant.The Despard wall plate format was popular once, to the point of being called a modern standard at the time. There were many switch, light, and outlet modules available, sometimes in combinations that would not pass muster today (e.g. a TV connector and AC outlets could be in the same box). I remember seeing a lot of them in US 1950's era kitchens (I'm old enough to remember the 60's myself). The basic Despard modules and wall plates can still be had. The variety of less common modules are no longer made.Here's a page that covers some of it:https://www.kyleswitchplates.com/despard-switches-outlets/

author: james_s
author_rank: Super Contributor
timestamp: September 21, 2021, 09:26:57 pm
content: Now that you mention it, my grandparents house had some switches in that configuration. There was one in the kitchen that had 3 switches in the space that would normally be just one modern switch. In the hallway there was one with two switches, one for the hall light and another that was a 3 way switch with the kitchen light, very convenient actually.