You got most of it correct. Initial acquisition was usually done by SAM in
Low PRF therefore you got a Low light, Switching to High PRF changed the
light to High. If you were in both AZ and EL sectors you got the AS
(Acquisition Sector) light. Launch for the SA-2 was done on acquisition of
additional signals in a two step process. Lights and tones for warning.
Not the most accurate indicator, but the only one we had.

Different strobe types were for frequency differentiation. Can't say more,
besides I forgot the break points. Too many systems in the head since then.

Les
F-4C(WW),D,E,G(WW)/AC-130A/MC-130E EWO (ret)


"Ed Rasimus" wrote in message
...
I'm not a "squeaks and beeps" EW, but here's what I was taught about
the sequence for the SA-2. The initial TDU (Threat Display Unit) light
were for "Lo" indicating a low PRF (pulse recurrence frequency), as
you got lit up with both beams of the Fan Song (Az & El), you got a
"Hi" for high PRF. When missile data upload was taking place, another
frequency was employed (that's where an EW could tell you more) you
got an "Activity" light and when command guidance signals were
received, indicating control signals to the missile airborne, you got
the "Launch" light.