[GreenKeys] [Bulk] Re: [Bulk] Re: Telephoto machines?

[Scott Johnson]

The teledeltos paper is an interesting thing.  Some 20 years ago, I was
employed by Motorola, and spent some time up in Oregon with Dr. Gertrude
Rempfer, who was an expert in electron optics (She was one of very few women
who worked on the Manhattan project).
She used teledeltos paper In conjunction with tee pins , which would then
have a potential applied.  By probing the paper (which has a very uniform
resistivity) with a voltmeter, one could see the field gradient, and have a
fair analog model of what the electron optics would do.  This was a
technique I used for years to ray trace when designing an electrostatic
electron optic, I had no idea the paper had another primary purpose!

Scott W7SVJ

-----Original Message-----
From: GreenKeys [mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of
Jeffrey D Angus
Sent: Monday, June 29, 2015 2:15 PM
To: Jim Haynes; Chris Elmquist
Cc: greenkeys at mailman.qth.net
Subject: Re: [GreenKeys] [Bulk] Re: [Bulk] Re: Telephoto machines?

On 6/29/2015 3:34 PM, Jim Haynes wrote:
> Western Union developed an electrosensitive recording paper in the 
> 1930s, which they named Teledeltos. As the ingredients were a secret 
> one could worry whether it emitted toxic fumes.
That's it, and that doesn't surprise me.
> W.U. had a thing called a regulator-inverter in the telegraph office 
> end of the circuit.  This applied AGC and also inverted the signal to 
> that the highest voltage was for black and the lowest was for white.
And yes again, NOT having the inversion in the middle explains it.

--
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com

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