[GreenKeys] Fw: BBC enquiry - telegraph machine

[WA5CAB--- via GreenKeys]

Although the term "pen recorder" or the similar "chart recorder" remained 
in use (especially among the raft of small oil patch companies who built 
their own), the term "oscillograph" became commonly used by companies like Bell &
 Howell, Honeywell, probably Gould, etc. who built commercial multi-channel 
ones that accomplished the recording process in various ways not limited to 
pen and ink.

In a message dated 06/18/2014 16:55:49 PM Central Daylight Time, 
62.5milliamps at gmail.com writes: 
> In the Bell System we called them "Pen Recorders"  They were used with  
> old alarm circuits for fire and police.
> We also used pen recorders, and the newer equivalent made by Gould, to  
> track voltages and troubleshoot dial pulse problems.
> 
> Don
> K9TTY
> 
> 
> 
> 
> 
> 
> On 17 Jun 2014, at 11:10 AM, Jim Haynes wrote:
> 
> An undulator is an ink recorder.  Like a slow oscillograph, the inked  
> line displays on a moving paper tape the polarity and amplitude of the  
> signal coming out of an ocean cable.  In ocean cable work they used  
> one polarity
> for dot and the other for dash, thus gaining speed.  And they tended to
> push the speed of signaling above the bandwidth of the cable, so that
> the operator had to infer what was sent from the wiggles on the tape.
> 
> Ink recorders were also used in high-speed Morse work (up to 500 wpm
> on radio circuits) but I don't think those were called undulators.  And
> they used conventional Morse make-and-break keying so the dashes were
> 3 times as long as the dots.
> 
> jhhaynes at earthlink dot net

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