AN/APS-4 also known as ASH
X-Band Intercept Radar; manufactured by Western Electric; used in C-47, C-117, P-38J, P-82D/F/H, AD, XBT2C-1, F4U-4E, F6F-3E/5E, SB2C-5, SBF-4E,
TBF-3, TBM-3S; British designation is AI Mk XV
for more technical info see also here:
US Radar: Operational Characteristics of Radar Classified by Tactical Application [FTP 217]
The ASH was originaly designed as ASV radar, but could be used for AI. I read that Avenger was used for night AI as a "hunter" with two daily Hellcats as a "killer".
A simplified display system was fitted to the AN/APS-4 to produce the AN/APS-6, also known as the AIA-1. The new display, which was only about 5 centimeters (2 inches) in diameter, effectively made the AN/APS-6 a "radar gunsight", allowing a fighter pilot to use the radar himself without need for a radar operator.