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On 4/9/15 5:30 AM, David wrote:
Hello List - The Sync Rotary Gap is truly a marvel of modern technology
:) and am amazed by how well it does what it does.
My big question to you long timers of the list. Who invented this
device? Who do we owe credit to for doing the original work on this
"Thing"?
Rotary sync gaps have been around for probably a century or more: as
long as there has been AC to synchronize with.
Rotary gaps in general are even older.
Back before vacuum tubes, radio transmitters often used rotary gaps. If
you're a ham, and know about RST (as in "UR 599, PSE RPT ALL"), the
"tone" originally referred to the audio modulation of the signal from
the rotary gap used in the transmitter, and part of knowing who was
transmitting was recognizing the unique rise and fall of the tone as the
rotary gap speed changed (from changes in the supply voltage, for instance).
Rotary gaps were widely used as radar modulators as late as WW 2. the
"rad lab" series of books from Lincoln Labs has design information.