[GreenKeys] Early Fax Machine/ NBC Radio News on the Hour

[Bruce Gentry]

Into the early 1960s the tone of a fax machine with a tympani roll in 
the background was used as the intro to the hourly news report on NBC 
radio. As best I can recall, the tone was amplitude modulated. However, 
I have seen  another wirephoto machine that used FM audio tone.  
Probably from the 50s or 60s, it was all tube and used a tuning fork 
oscillator to drive the drum motor.

On 12/29/16 11:15 PM, Jones, Douglas W wrote:
> From:  Jim Haynes [jhhaynes at earthlink.net] Thursday, December 29, 2016 10:04 PM
> Subject: Re: [GreenKeys] Early Fax Machine
>
>> I believe it requires a DC loop to operate.
> Looking at the last photo on the E-bay page, there's a chopper disk in the light path from the paper to the photocell.  This looks like it will chop the light beam at an audio frequency.  That means that it's highly likely that the signal will look like an audio signal on the wire, so it will probably work over voice-grade phone lines.
>
>> Also for recording it requires Teledeltos paper, and I don't think that is available anymore.
> Teledeltos paper has some interesting uses in analog simulation.  It's still a great way to do quick and dirty computations of static electric fields around complex shaped objects.  Just paint conductive paint on the paper in the shape of your object and then apply a voltage and measure.  It's written up in the Wikipedia page on Teledeltos paper.  As a result, it's still on the market.  See, for example:
>
> -- http://www.betterequipped.co.uk/teledeltos-conductive-paper-prd1516-pack-of-10-sheetsp-1262
>
> A ten-pack for 14 pounds, GB.  The sheets are 52cm X 37.5cm, so you'll have to cut them down to fit the DeskFax machine.
>
>                   Doug Jones
>                   jones at cs.uiowa.edu
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
>
> 2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/
> 1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html
> Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to ka2ivy at verizon.net
>