# Help ID this mystery jack

**URL:** <https://boards.straightdope.com/t/help-id-this-mystery-jack/590196>\
**Category:** Factual Questions\
**Created:** [July 24, 2011, 7:38pm UTC](https://boards.straightdope.com/t/help-id-this-mystery-jack/590196 "2011-07-24T19:38:08Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![I-VI-ii-V](https://avatars.discourse-cdn.com/v4/letter/i/c89c15/32.png) [@I-VI-ii-V](https://boards.straightdope.com/u/I-VI-ii-V)\
**Post date:** [July 24, 2011, 7:38pm UTC](https://boards.straightdope.com/t/help-id-this-mystery-jack/590196/1 "2011-07-24T19:38:08Z")

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A mystery jack was found in the wall of my house (built in 1928) above the baseboard. The front appears to be an approximately 1/4" diameter input jack; the back is porcelain. Two cloth clad wires were connected to it: one connected to the back of a metal single gang electrical box (I believe this was used as a ground); the other wire goes up towards the ceiling/roof (this one has no power running through it and I do not know where it terminates). It was covered with a single hole plate like you would use for a coaxial cable. Here are some pictures:

[![Imgur](https://live.staticflickr.com/6129/5971397864_77b49d70dc_b.jpg "Front of mystery jack") ](https://www.flickr.com/photos/65561256@N05/5971397864/in/photostream)

[![Imgur](https://live.staticflickr.com/6121/5971399286_2c6052bc55_b.jpg "Back of mystery plug") ](https://www.flickr.com/photos/65561256@N05/5971399286/in/photostream)

Possibilities:

1. old telephone jack
2. old antenna jack
3. old cable TV jack (\<– highly unlikely)
4. something else

Has anyone ever seen anything like this?

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**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\
**Post date:** [July 24, 2011, 7:47pm UTC](https://boards.straightdope.com/t/help-id-this-mystery-jack/590196/2 "2011-07-24T19:47:21Z")

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Wild guess, but it looks like an antenna jack from the golden age of radio.

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**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\
**Post date:** [July 24, 2011, 7:48pm UTC](https://boards.straightdope.com/t/help-id-this-mystery-jack/590196/3 "2011-07-24T19:48:11Z")

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Maybe an antenna connection for Ham Radio?

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**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\
**Post date:** [July 24, 2011, 7:51pm UTC](https://boards.straightdope.com/t/help-id-this-mystery-jack/590196/4 "2011-07-24T19:51:10Z")

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an antenna jack for AM radio receiver would be my thought. FM and TV antenna jacks were different.

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**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\
**Post date:** [July 24, 2011, 8:53pm UTC](https://boards.straightdope.com/t/help-id-this-mystery-jack/590196/5 "2011-07-24T20:53:01Z")

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Looks like a [1920s style antenna death jack](http://books.google.com/books?id=wNoDAAAAMBAJ&pg=PA672&lpg=PA672&dq=antenna+%22wall+jack%22+am+radio&source=bl&ots=aTDqUpX5-g&sig=h9iQz5Yk-IMWt243YthylNtS-b0&hl=en&ei=goQsTtYghMWxApyj4YcL&sa=X&oi=book_result&ct=result&resnum=10&ved=0CFQQ6AEwCQ#v=onepage&q&f=false) is correct.

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**Author:** ![I-VI-ii-V](https://avatars.discourse-cdn.com/v4/letter/i/c89c15/32.png) [@I-VI-ii-V](https://boards.straightdope.com/u/I-VI-ii-V)\
**Post date:** [July 24, 2011, 9:04pm UTC](https://boards.straightdope.com/t/help-id-this-mystery-jack/590196/6 "2011-07-24T21:04:32Z")

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Good work guys, especially **ZenBeam** for the pic.