their
Nixon was elected November 5, 1968 and was inaugurated January 20, 1969.
He left office August 9, 1974.
NPR replaced the National Educational Radio Network on February 26, 1970, following Congressional passage of the Public Broadcasting Act of 1967, which was signed into law by LBJ.
lol. No. How would they relay or amplify anything?
Morse Code. Named after Samuel Morse.
Technically: no.
AM stands for amplitude modulation in which the amplitude (signal strength) of a wave is varied in proportion to that of the message signal, such as an audio signal. It was not developed until the early 1900s
Telegraphy in the transcontinental railroad era worked via induced current in the wire, which worked when current flowed through an electromagnet’s winding, creating a magnetic field which attracted an armature, pulling it down to the electromagnet, resulting in a "click" sound. It is, simply, a make/break system. The signal is present or not.
When the current ended, a counterweight pulled the armature back up to its resting position, resulting in a "clack" sound.
Thus, as the telegraph key at the sending end makes and breaks the contact, the sounder echoes the up and down state of the key.
You may be trying to describe on-off keying, which HAM operators name “CW” (continuous wave), but even here there is a fundamental carrier, whereas most early telegraphs were DC.
