Comments by "Sar Jim" (@sarjim4381) on "Room 40 - Signals Decryption and Intelligence Analysis in Bowler Hats" video.

The problem of telegraph decoding precedes navies. When telegraphs first started to be used commercially, messages were charged by the letter. This was very expensive, especially for transatlantic cables, and prompted various commercial entities, including Western Union, to come up with number blocks and code books so entire phrases could be transmitted using a single code block of five numbers or letters. This didn't provide signal security since codes books were widely available. However, large business soon developed their own encoding techniques and private code books so competitors wouldn't be able to read their messages if they were intercepted. This was the beginning of using codes for operational security.
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@jamespfp They also invented Kurier, a system of flash messaging the could send 600 WPM. NOt only was it fast, but the messages were sent on a deviation from center frequency of as much as .200 MHz. That made it difficult to detect the transmission with a standard AM receiver. A Navy study of German submarine communications after the war found out about Kurier, but they never knew it existed during war, so it was never DF'd. As the study noted, if Kurier had been in operation earlier in the war the Allies would have been in serious trouble when it came to knowing where U Boats were.and what they were up to.
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@jamespfp Pretty amazing for the 20's, and led directly to FSK and PSK for we amateurs. The only problem was the large bandwidth and slow speeds. Attempts to send faster speeds really hogged the bandwidth, but it was only system that could remotely print out a message. I'm sure there were many errors when messages were sent by CW under poor conditions and we had to depend on humans operators to get it all right while it was in code. I know I couldn't do it.
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@jamespfp Indeed. I wonder what else the nazis were working that we've never found out?
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@jamespfp Yes, the Nazis had tons of paper projects that were either impossible or just couldn't be done in time. The had plans for a ballistic missile with a 6,000 mile range that, if they had unlimited strategic materials and two more years, they may have actually been able to make it. Desperation is the mother of many inventions. Probably shouldn't get into this here, but I suspect Hitler would have been happy to be part of our current environmental movements, and he would have been a leader in the antismoking campaign.
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