[keith49vj3]

My wife was watching a documentary on Hedy Lamarr last night (on PBS).  Turns out she was both an inventor and an actress.  She is credited with inventing a jam proof guidance system for torpedoes.   She says she got the idea from playing with a Philco with a mystery control.  A Mystery control philco was featured in the show.  Is this old Philco trivia?
Keith

[Arran]

I caught maybe the tail end of that "documentary" a year ago, and I am rather skeptical about some of their claims, including giving her credit for cell phones. Much like I was skeptical about how much of a contribution a research lab at MIT actually made to radar, implying that they alone were allowed access by the British to the cavity magnetron after the war started. Whomever made the doc. seemed to be oblivious to the fact that mobile radar trailers were already in existence before Pearl Harbor, one in fact detected the Japanese strike force at least an hour before they made it to Hawaii. The trailer was developed and built by the American Westinghouse Company, but you probably won't see a documentary about them because they were a corporation with full time researchers, scientists, and engineers, and not a member of the Washington cocktail circuit, or on a theater marquis. You have to be very careful what you see on PBS, sometimes the "documentaries" are made by people who are either fanboys/fangirls, or someone with an agenda, where they unwilling to research conflicting claims.
Regards
Arran

[morzh]

Yes, I read about her some time ago and was amazed. This torpedo thing included spread spectrum plus frequency hopping that is used in todays CDMA, Bluetooth and WiFi.

Beauty and brains, and either one is first class!

[Arran]

I found out what it actually was, with very little research. Apparently the idea was that they would have the transmitter, and receiver, switch frequencies using a punched out paper roll like a player piano. Nothing was ever built, not even a prototype, just some drawings, and a pair of patents for the device. From what I read frequency hopping only works well at higher frequencies, but higher frequencies do not transmit well under salt water, I don't know if this is true but for whatever reason the U.S Navy rejected the idea believing that it was impractical.
Regards
Arran

[morzh]

Doesn't matter. The idea is patentable and was very smart. And gave rise to real applications later.