Vietnam era F-4s Q

Radar beacon mode is a different animal altogether than the IFF
interrogators we've been talking about. The rendezvous beacon that tankers
carried and the one carried in F-4s (SST-181X, sometimes called "Skyspot
Beacon" though I don't know if that name's official) are interrogated by the
radar itself using a selected radar PW/PRF as I recall, not a separate
interrogator as with APX-76 or 81. The beacon in the F-4 had a code that
had to be preset before the flight by maintenance since it was dialed in on
the SST-181X itself, which was buried inside Door 19. I don't know what
kind of beacon the tankers carried or whether it was accessible in flight.
Lots of US military aircraft radars can interrogate rendezvous beacons.
Even the APN-59 radar in the C-130 could do it, though cargo Herks had no
IFF interrogation capability.
Scott Wilson

"Ed Rasimus" wrote in message
...
(Smartace11) wrote:


I presume you meant APX-76 for tanker join-ups? Combat Tree wouldn't
seem to
be
useful for them, unless our KC-135s were carrying Soviet IFF systems

At that time the whole system was called Combat Tree, as least by the
aircrews.
I was a dumb crew dog and just flew the things


I'll go with Guy on this one. The beacon mode of the E-model radar we
were using at Korat sure wasn't Tree. It worked on 100 and 200 mile
scope and was nice for finding your tanker. But it was strictly
"cooperative" target recognition.

I used to tweak Rod Bates, my back-seater after Linebacker II, to take
tanker "judy" as far out as he could. If he could get the tank to
squawk, he'd try to judy in the turn out of traffic. He got some
contacts at 125 to 150 miles and ran the whole intercept.

Of course, the beacon return on that long a range was a wide slash on
the scope. It got you going in the right general direction and you got
a refined return as you closed the range. By the time you got to skin
point you would be right on track.

Sorry bout this one, Steve, you're old memory is fading. CRS, I guess.



Ed Rasimus
Fighter Pilot (ret)
***"When Thunder Rolled:
*** An F-105 Pilot Over N. Vietnam"
*** from Smithsonian Books
ISBN: 1588341038