[GreenKeys] oddball teletype recorder RO-133/FRR

[Sam Hallas]

Jim Haynes wrote:

> That kinda reminds me of the way the Brits were
intercepting the
> online TTY signals FISH in WW-II.  They didn't trust an FSK 
> demodulator driving a reperf to make an accurate copy of the 
> encrypted signals. Instead they copied them on an ink recorder and 
> hand-transcribed the characters to paper tape.

The inking device is known as an 'undulator'. I took a picture of one
during a visit to Bletchley Park some years ago.

<http://samhallas.co.uk/telhist1/hist2/undulator.jpg>

Sam

-- 
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus