Today's post brings us YouTube videos from several hobbyists who have built and operated some of the transmitters we have written about in the past - if you were curious about if and how these transmitters really work, look no further than Google's billion dollar baby.
We'll begin with a video from a hobbyist who built the Sci-Toys.com four-pin crystal oscillator transmitter, who reports "I started with the version here at sci-toys.com transmitter plans. The basic idea is to run a signal through a crystal oscillator, which when output to an antenna, sends radio signals at a fixed frequency (in our AM band's case, 1.0 and 1.2 MHz). See the schematic at crystal oscillator schematic." Nice work and a nice demonstration of a project that is often criticized on some message boards - sounds pretty good to me!
Next, will take a look at a couple of videos from the builders of a popular tube kit,
the iTx two tube unit, available from Vintage Components in the UK.
The first builder tells us of a "Home made vacum tube MW broadcaster demonstration - This is a kit which I purchased online and built onto the supplied PCB, it works extremely well and is called the iTx if I remember correctly. The unit can operate on between 27 and 90 volts dc with a heater voltage of 1.4 to 1.5 volts dc. An ac heater supply is unusable due to the hum created which totally blanks out the audio being broadcast."
Another video from an iTx kit builder here: A Nice kit to order and to make - iTx AM Tube Transmitter Kit
Many more videos about low power, home made AM transmitters can be found here: YouTube search AM transmitters Enjoy!