The Centalic PQ75-A-4GG is a spring-loaded in-circuit test probe for fixtures on 1.91 mm (75 mil) centres, running in an RQ75 receptacle pressed into the probe plate.
The A head is a cupped (concave) tip 1.27 mm across. The cup captures a round target and holds it centred, so it is the head to use against component leads, wire ends, solder bumps and filled vias — anywhere a flat or pointed tip would slide off to one side. On plain flat pads a needle or serrated head gives a more repeatable contact. Spring force is 4 oz (112 gf), the lightest of the three PQ75 options.
Cupped (concave) tip, Ø1.27 mm; plunger diameter 0.64 mm, barrel diameter 1.02 mm
Recommended minimum centre spacing 1.91 mm (75 mil); mounting hole Ø1.35 mm
Rated stroke 4.30 mm, full stroke 6.35 mm
Spring force 112 gf (4 oz)
Current rating 3 A continuous; contact resistance 40 mΩ
Receptacle brass and barrel bronze, both gold plated; plunger BeCu; spring music wire, gold plated
