[GreenKeys] news wire photos

[Lee Mushel]

Nick,

I can tell you are far too young to remember what things were like in, let's 
say, 1948!.   Indeed, those "photos" that appeared the daily press were of 
miserable quality.   The image paper was "special" and I can see carbon 
black to enhance the conductivity for "burning".    I was able to 'transmit' 
an image with quality equal to what appeared in the press.   The stuff in 
Life Magazine was entirely different.   And what are you talking about 
"color?"   I never tried regular photo paper.   I had enough of the intended 
stuff to last during the period of my 'experimentation."

Lee
----- Original Message ----- 
From: "Nick England" <navy.radio at gmail.com>
To: "Lee Mushel" <herbert3 at centurytel.net>
Cc: <GreenKeys at mailman.qth.net>
Sent: Friday, June 17, 2011 10:46 AM
Subject: Re: [GreenKeys] news wire photos


>I think the spark-paper method could only be used for black/white
> imagery rather than news-quality photos - the resolution wasn't good
> enough to provide half-tone images as used to print gray-scale photos
> in magazines, etc. For actual gray-scale photos, the receiving paper
> was regular light-sensitive photographic paper and a variable
> intensity lamp was focused to create the spot on the paper. Lamp
> intensity was determined by the incoming AFSK frequency (1500-2300
> cps)
> After reception, the paper was developed using normal photo chemicals
> in a darkroom.
>
> Photos and block diagrams at
> http://www.navy-radio.com/rtty-fax.htm
>
> I have an RD-92/UX spark-type receiver that I hope to get working
> sometime and drive via ??? - I don't have a transmitter....
>
> cheers,
> Nick K4NYW
> www.navy-radio.com
>
>
> On Thu, Jun 16, 2011 at 6:51 PM, Lee Mushel <herbert3 at centurytel.net> 
> wrote:
>> Gentlemen:
>>
>> Once again your notes stir some thoughts that I had forgotten. But not
>> exactly true this time. You see I happen to have two of the "old" fax
>> machines sitting on a shelf in my shed. I would trade them for a Flex1500
>> but anyway, I can't remember what swapfest I got them at but would remind
>> you that there was a time when you would see newspaper photos that said 
>> they
>> were "AP wirephotos." Yes, that was fax. Detection and sending was
>> relatively simple. You put the image you wanted to send on a motorized
>> drum (it was held in place with a spring). As the drum rotated, a 
>> photocell
>> was moved across the drum face. On the receiving end the image was
>> "developed" by a spark from the end of a "wire" you carefully positioned
>> over the special paper on an identical drum.. You started the machines 
>> and
>> after a suitable time to allow the drums to "synchronize" the image was
>> sent.
>