Antique meter

[colum]

Sorry I cannot supply photos at this time
I have an old Meter from the beginning of transatlantic phone service.
It consisted of a bulb as a light source and a tiny mirror suspended on a very thin wire and that wire was connected to the magnets center and rotated in a magnetic field so at rest it was a center reading meter. The image of the lit bulb element reflected on some internal mirrors that gave it more sensitivity and the image landed on a glass window.
This type of meter was used to test phone lines before electronics.

If some one heard or know the name of this meter I would appreciate it
Many thanks

 

[Bluejets]

Photos would be almost essential.

 

[Delta Prime]

Hello there.
single-sideband suppressed-carrier method of transmission
Had to use the way back machine.
Good stuff.

 

[davenn]

Hello there.
single-sideband suppressed-carrier method of transmission
Had to use the way back machine.
Good stuff.

I dont see how a radio circuit relates to the OP's telephone system ?

 

[Delta Prime]

I dont see how a radio circuit relates to the OP's telephone system ?

Very good point!
I don't think it does.
Apologies to the op.

in 1927, transatlantic telephone service was radio-based. Source: Wikipedia Transatlantic communications cable.
Starting in 1927, transatlantic telephone service was radio-based. Source: Wikipedia Transatlantic communications cable
In 1927, a second transmitter was installed to initiate the first transatlantic commercial telephone service, linking New York and London on 60 kHz using single-sideband modulation.
Instead of bouncing the radio waves off of the ionosphere like like Marconi did .
At 60 kHz I doubt anything would jump off the ionosphere and more than likely used ground wave propagation which gets you past line of sight transmission which is limited by The horizon ( curvature of the Earth) Ground wave propagation follows the contour or curvature of the Earth. And is still use today! By yours truly.
I may be wrong... well let's play it safe. I don't believe the first commercial communication was full duplex

 

[colum]

Hello there.
single-sideband suppressed-carrier method of transmission
Had to use the way back machine.
Good stuff.

Thank you Delta Prime for that research.
This type of instrument tested the transmission lines between Canada and Ireland which is the closest point in North America because it was the most sensitive test before electronics were invented.
I had one that was used as a lie detector and was the size of a small suitcase and did not work vey well. I saved the meter.
As I understand from some instructions that I lost. The rotating element is a mirror instead of a needle and to preserve its sensitivity it has a circuit of low resistances ( in paralell across the + - terminals ) such a way that the current bypasses the meter movement to change the sensitivity.
It seems that a small volt is applied and is set up like an Amp meter I guess ??
Some of this is a guess on my part and I would appreciate any input
Thanks colum

 

[Bluejets]

It seems that a small volt is applied and is set up like an Amp meter I guess ??
Some of this is a guess on my part and I would appreciate any input

Yes, it's the button called "attach files"....

 

[colum]

If I had files I would not be asking these questions or need to.
I was hoping someone would know how this meter is hooked up

 

[davenn]

If I had files I would not be asking these questions or need to.
I was hoping someone would know how this meter is hooked up

that's why we asked for pic's so we could see what you are referring to

Dave

 

[colum]

I just Googled it and it was called a Mirror Galvonmeter with alot of history and is still used today in Laser work and it was used originally in underwater long distance communication tests
I still have to figure out the required Parrarell low res ct and what voltage is best but that is just basic electricity for a moving coil Amp meter Be well colum

 

[Bluejets]

hehehehe.....and still no photo....... I have to wonder sometimes.