|
Post by RAF on Jul 20, 2005 19:30:46 GMT -4
I was watching my Apollo 11 DVD today (of course!!) and I have a question about some "sounds" I heard. I'm not sure that this hasn't already been discussed (I may even have been the one to ask, but old age is making me forgetful)... ...anyway... While watching, I Kept hearing what I can only describe as "someone" dialing a touch-tone phone really fast...at least that is what it sounds like... Can someone clue me in as to what I'm hearing? Thanks...
|
|
|
Post by Joe Durnavich on Jul 20, 2005 20:00:25 GMT -4
My working hypothesis has always been crossover on long-distance circuits. Long distance phone calls used to have similar sounds back in the days of analog.
|
|
|
Post by RAF on Jul 20, 2005 21:04:34 GMT -4
My working hypothesis has always been crossover on long-distance circuits. Well, that is what it sounds like. It would be the simplest explanation.
|
|
|
Post by JayUtah on Jul 22, 2005 12:51:09 GMT -4
Back in the olden days, the control signals for phone switching were sent in-band and were of the same format as touch-tone dialing signals. The MSFN utilized leased phone lines in part, so that's one possible explanation. However many of the telemetric signals used in Apollo were of the same type of encoding and modulation as the phone switching signals. I think that's less likely because there was greater attention paid to the USB signal organization. That type of crossover is unlikely.
In any case that sounds like a Mike Dinn question.
|
|