MIflyer
1st Lieutenant
The APN-1 is a radar altimeter, sometimes called a "radio altimeter" used in WWII. It operated in the 420 MHZ range and gave an indication of altitude on a gauge. It had two ranges, 0-400 ft and 0-4000 ft. It was widely used on USN aircraft, since determining altitude above the water at night was a very difficult and very important task. If anyone wants to see one, including the insides, I have one of the critters.
Attached are photos of the RT-27/APG-4. This is recognizably a version of the APN-1. The "Gun Laying Radar" designation comes from the use of the set to launch torpedoes from aircraft. Obviously, knowing the altitude is critical for dropping torpedoes, which is why this version of the APN-1 was built. Now,as to why they could not have used an APN-1, I have no idea.
Attached are photos of the RT-27/APG-4. This is recognizably a version of the APN-1. The "Gun Laying Radar" designation comes from the use of the set to launch torpedoes from aircraft. Obviously, knowing the altitude is critical for dropping torpedoes, which is why this version of the APN-1 was built. Now,as to why they could not have used an APN-1, I have no idea.
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