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Listed on EBay, a strange Edison radio device of some sort? 300633870904

Looks like an Ediphone motor that someone doctored up to look scientific

Made up from an Ediphone motor mounted to a piece of mahogany and some added bits. (The "Edison" decal on the base is a 1970s reproduction featuring the "i" dotted with a round-topped blob instead of a triangle.) I don't know what it's supposed to do, but I must admit it looks nice!

George P.

It is a rotary spark gap for a wireless transmitter.

Probably a modern "reproduction", as a cheaper motor, sans governor would have been sufficient for a "ham" in the old days.

The rotary gap improved the inteligibility of the transmitted note of a transmitter running off of 60 cycle current, replacing the characteristic low growl
of a straight AC transmitter with a more-or-less musical note. In the case of a relaively high-powered transmitter, the rotary gap also aided in quenching the .arc which would otherwise form.

It would make a nice rotary gap for a Tesla coil.
I used a coil with a simpler version of this for demonstartions.
Kevin

[quote="Uncle Vanya"]It is a rotary spark gap for a wireless transmitter.

OK, I think I know what a spark gap is now - but is this thing old? It does not look like a modern reproduction to me except for the 70's decal you pointed out. It could have been actually used as part of a vintage radio transmitter set back in the early days of radio, or ham radio? Maybe it was mounted to a table and the board you see in the photo is just a replacement for display purposes?
Anyway - very cool Edison piece put together by someone (a radio operator maybe) who really knew what they were doing.... And it looks dangerous to me with all that exposed electrical connections, etc.

Definitely not old. Just something fabricated using a flashy-looking motor and a few other old parts.

Ok, a real Edison Ekonowatt motor.
From ebay:
But a Edison Spark Gap...?

Take a look to this Radio site:
http://k8cix.tripod.com/crystalradio.html

In the second half of the page, you will see this -
Doesn´t it look familiar

Cool - but this one has a brass ID plate,,, but I cannot read the inscription unfortunately. I wonder how many of these were actually constructed, and when?

It's definitely a new item fabricated with some old parts, quite OK as long as it isn't passed off as being a genuine item. That radio builder in the link is in a gray area. A lot of his stuff is built using old parts and is fitted into old wood cases- many the sort used for old quack medical devices. He's not selling them as old, but I'm certain that in the future some of them will resold as period pieces.

I don't like to think of Ediphones being stripped for the motors, but these office machines don't have much collector's interest- so they tend to gather dust anyhow. It has a nice Steampunk look about it.