Contactor Unit BC-608-A of RC-96A System Pipsqueak Grumman The front mounting bracket is

The front mounting bracket is set in place but not screwed in

SA-1/ARN-1 was a component of Radio Set AN/APN-1

This is a nice example of the US Navy's Vertical Speed Indicator R-88-I-750 as used in the SB2C Helldiver Dive Bomber of WWII

the operating ranges for each parameter are labeled in green/red on each scale

and one adjustment knob

Contactor Unit BC-608-A of RC-96A System Pipsqueak Grumman The front mounting bracket isHere is an excellent example of the WWII era Contactor Unit BC 608 A, a component of the US Army Air Force's RC 96 A Contactor System intended to work with the the British RAF "Pipsqueak" system. Pipsqueak was a simple radio navigation system used by the British during the early part of World War II. Pipsqueak used an aircraft's voice radio set to periodically send out a 1 kHz tone which was picked up by ground based high frequency direction finding