HME WM-300A 9D Wireless Receiver

The HM Electronics (HME) WM-300A is a legacy, fixed-frequency wireless microphone receiver that dates back to the era before digital, frequency-agile systems became the industry standard. Commonly paired with HME's matching handheld (such as the M250) or lavalier transmitters, this receiver was a rugged, highly reliable staple in corporate AV racks, houses of worship, and regional live sound rigs throughout the late 1980s and 1990s. The "9D" designation in the model name is critical—it indicates the specific, crystal-controlled radio frequency channel that the receiver was factory-tuned to. Because it cannot scan for open channels or change frequencies, any transmitter used with this receiver must also be permanently stamped and tuned to channel 9D in order to communicate.

While it lacks the modern conveniences of LCD screens or automatic frequency coordination, the WM-300A was prized for its robust analog FM transmission. Operating in the VHF band, it utilized a dual-antenna diversity design, actively monitoring the signal hitting both antennas and instantly switching to the strongest one to prevent dropouts as the performer moved around the stage. The rear panel provided everything needed for professional integration, including a balanced XLR output for running a clean signal to a front-of-house mixing console, and an unbalanced 1/4-inch output for plugging directly into a local PA system or instrument amplifier.