MPARC owns and operates the ’37 Machine located on the WXGM tower in Gloucester. It has been on the air since 1988, and has a coverage area including the middle peninsula and lower peninsulas of Virginia.

The W4HZL repeater has a frequency of 145.370, with a negative offset. A 100.0 Hz tone is required for accessing the repeater. There is also 100.0 Hz tone on the output. This is useful for combating interference by using the “tone squelch” capabilities of modern rigs. When “tone squelch” is employed, only signals containing the provisioned “sub-audible” tone will be passed to the receiver.