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

[WA5CAB at cs.com]

That machine description sounds like what the Navy used in the 1960's.  But 
our converters were audio FM, not AM.  The audio output from the receivers 
(in our case, R-390A) sounded like a FAX circuit's audio of today.  The FM 
is converted by the converter to AM to feed the printer.

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480

In a message dated 01/02/2017 13:16:08 PM Central Standard Time, 
ka2ivy at verizon.net writes: 
> My mother was a telephone operator in San Francisco in the late 1940s, 
> and often handled fax calls. There were favored trancontinental circuits that 
> would be used when possible. One other detail was a physical block the 
> operator would put on the switchboard keys of a circuit handling a fax so 
> there would be minimum chance of disruption. In the time of my war, fax 
> machines in the Air Force were usually maintained by ground radio technicians like 
> me, and good circuits were a serious problem in southest Asia. Although we 
> were an Air Force base, our outside lines were provided by the Army 
> Stratcom service. Usually the quality was nominally satisfactory, but often noise 
> and dropouts caused serious problems. 99% of the transmissions were 
> weather maps, so some transmission defects could be tolerated or might not even 
> be seen. The machines we normally used were built by Litton and used 
> magnetic writing heads on a toothed belt to scan across a sheet of carbon paper 
> onto white paper beneath. Keeping the heads and their contacts and rollers 
> clean and operating freely was a constant pain. We did have a TXC-1 as well, 
> used on occasion. 
> 
>      Bruce Gentry, KA2IVY
> 
> On 1/2/17 12:58 PM, Sheldon Daitch wrote:
> 
> >> The AP wirephoto circuit was still amplitude tone modulated at least up 
>> until the 1980s.
>> 
>> I think the same for the UPI wirephoto network.
>> 
>> I don't remember the frequencies used and I am almost sure the two 
>> networks had different tone standards.
>> 
>> 
>> 
>> 
> 
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