HC-4 is the Heil Microphone element, NOT the entire microphone.The HC-4 is no longer sold as a separate repair or retro-fit part by Heil.
Majority of Heil microphones use a 4-pin XLR connector,
older ones used a 3-pin XLR (widely used in professional audio).
Heil Microphone Adapters and Selectorhttp://www.heilsound.com/amateur/adapters/
Balanced to Unbalanced Wiring
Connecting 3-pin Balanced to 2-pin Unbalanced Inputshttp://www.heilsound.com/amateur/tips/balanced_to_unbalanced.php
The ground is on the outside on the mic and the positive on the center?
Generally true for 2 connection dynamic microphone elements.
Elecret mic elements require voltage for operation.