[R-390] Synthesizer Phase Noise

[Flowertime01 at wmconnect.com]

Fellows,

I had a couple of these synthesized receivers to take care of for a year.
A human did not actually listen to these receivers.
When the system found a signal it sounded an audio alarm.
Some human (Senior NCO in the bay) looked at the frequency display yelled 
out the numbers, pointer at some op, pushed the button to silence the alarm 
and send the system seeking the next new transmitter to pop up with the set 
band scan limits.

The system was 5 racks wide and state of the art in 1965. 
Today its hand held and called a scanner.

No one cared how much noise was in the system. Those receivers were not for 
human ears to listen to. The goal was to get that silly display to read 
accurate on every MHz of the R390/A without the need to cherry pick crystals or 
zero the PTO every time the system changed the MHz shaft.

Once the scanner found a signal that just popped up, its job was to alert 
some humans and pass the task of doing signal copy back to humans with good 
receivers. The only thing was to get the best frequency possible from the 
system to the operators. 

You do not do signal intelligence collection with one operator one receiver 
and one antenna. You deploy farms of antenna, lots of receivers, lots of 
operators, and some few special systems that trade phase noise and audio 
quality for robotic persistence, You divide machines to special task and manpower 
to special skills and operations. You provide systems with specific 
attributes. You let some other features fall where they may. 

On a bad signal you may have patched the scanner output over to an operator 
working with a set of split head phones. His R390/A in one ear and the 
scanner audio in the other ear. As soon as the operator had the scanner signal 
found on his receiver. I said found not tuned, not optimum, not copied, not 
worked. The operator dropped his split phone. As soon as the split phone was 
dropped (as thrown on the floor to get both hands back on the mill) The 
scanner operator hit the seek button to send that system seeking the next new 
transmitter to be found.

The guys using these special systems did not care about no stinking phase 
noise. They loved that system that would just scan a band segment over and 
over and over and never miss a new signal. Give you the best indicator of 
where to tune your receiver to let hear the new signal. Ignore the ones it had 
heard before. And do several other computer programmable tricks. The system 
could scan over ear drum busting signals looking for the low watt signals 
trying to hide under the big signals. The scanner would seek and seek and seek 
just waiting for a new signal to pop up. The System worked well enough. 
Operators were happy to set it up and let it seek. That audio alarm going off 
was more of a nuisance factor to 14 other guys who had a signal they were 
working. Than the phase noise was to the 15th guy seeking a new signal to work.

Roger.