TRIVIA, and a prize to the winner

[BDM]

Ok boys & girls. I have a little contest. What was the modulation mode/type used in our telephone systems for almost a century. And still is to a certain degree. Also, what was it first referred to as? So, you have to get both answers correct. Whomever wins, gets a complete phone from me. No, not one of my rare ones, not a candlestick. But, a complete workable phone that will need restoration(cleaning, etc.), but no junk! Could be a 500 series? Could be a Trimline? Could be a Princess. Who knows But hey it's free and will be no cost to you. So, have at it. BTW, no close answers. Only the proper answers will do. First one to post the correct answers, gets it.

This contest will end twelve hours after the posted time.


P.S. If this one goes easy, I'm going to make sure the next one is tough

[benhutcherson]

It's called pulse code modulation, and was originally referred to as time division multiplexing.

[BDM]

Nope That came later.

[Kittybell]

Was it "Magneto"?

[JimH]

Amplitude Modulation, also called "undulatory currents" ?  Just a guess 

[BDM]

Amplitude Modulation, also called "undulatory currents" ?  Just a guess 

BINGO, the winner. Ok, next round, I'll come up with a harder techincal question. Of course, many of you guys are way ahead of me(that's no joke), so I need to really research & think!

Email me Jim.

[Dennis Markham]

Sounds like a radio (AM) thing..........

[HobieSport]

Of course we want a pic of the prize phone...