67Dart273
Well-Known Member
Well and remember, too, that all parties, Axis and Allies pretty much developed RADAR from an unreliable toy to having RADAR directed guns and weapons.
The magnatron, "that thing" in your microwave oven, is the one component that made all that possible, and it IS STILL basically unchanged today in some applications.
Our GCA (Precision approach RADAR) that I used to maintain was developed late in WWII, and used during the Berlin Airlift. The precision RADAR section used a transmit/ receive frequency close to 10 gigahertz, in those days it would have been written 9080 megacycles (or more properly, 9080 megacycles per second)
Our GCA had what is known as MTI, or "Moving Target Indicator" which involved phase cancellation through a mercury delay line in the IF (intermediate frequency) amplifier
What this did was, to reduce ground "clutter" because the delayed and "undelayed" receive pulses would happen at the same time (phase) and be canceled out, leaving you with a "clean" display. It also involved a primitive form of AFC (automatic frequency control), and considering, once again, the transmit frequency being used and the period in which this was developed amazes me to this day.
This was all done with vacuum tubes. The only "solid state" device in the entire RADAR was the receiver detector diode, which equates to that used in a "crystal radio."
I cannot remember anymore if ours used IN21 or IN23 series diodes, but this is what they look like:
