There were faster ways to communicate, but they were more expensive. In upcoming letters there is mention of Noel sending a letter via airmail to the West Coast to try to speed things up, and also of an occasional telegram or cable.
About the Amplifier:
|Tubes as used in a tube amplifier.|
Courtesy of Mikah Taylor via Flickr
I wish I remembered the story better, but I think Noel built a giant tube amplifier that was used in movie theaters to amplify the soundtracks to films. In 1931, we are right in the transition from silent to talkie films. The way I remember it, he would use the amplifier to play a recorded score to a silent film, but it was probably also used to broadcast the sound for a talkie.
In reading the letters, it appears to me that Rex is a friend of Noel's who was also interested in movie theater sound systems, with references to Rex having jobs for radio corporations "testing speakers", and "installing some talkie apparatus". Rex will also be mentioned a lot in future references to selling the amplifier.
I'm sure Noel had a lot of money tied up in such a large tube amplifier, and with money so tight, they were eager to sell it.
UPDATE 4/26/12: I found an audio tape that I recorded in 1980 in which Noel explains his relationship to Rex Baker and how the two of them got into making radios and amplifiers together, plus what happened to the amplifier. See Treasure! Rex Baker and the Wireless.