Our club layout has a GML Enterprises walk-around DC throttle installation with adjustable dual pulse operation, which appears to be model # PL-2. This has a 3-position switch (1-OFF-2) and a variable pulse control knob (min to max), and we are trying to determine if the center "OFF" position is intended to turn off the pulses and allow DC-only mode. Unfortunately, GML no longer has an active website (I have heard the gentleman who ran the business passed away) to locate a user guide and installation instructions for this equipment. However, The Wayback Machine had archived copies of the site, and I was able to find a document that provides a brief description of DC throttle options. This document states "The center switch position is the Pulse Off mode and all throttle operations are normal. (*)" No further detail is provided, and no explanation of the asterisk note is given. Does anyone have experience with this model of the GML throttle, or has copies of any additional documents (user guide or installation instructions)?
If you are unable to find additional documentation, are you able to open the unit? By looking at the switch, it'd be easy to confirm your suspicions. I think you are right, because MRC's throttles had a Pulse On/Off switch. That way pulse power could be cut out at speed to keep motors cool. I think it was @Doug Gosha here who recalled that us early N Scalers got pretty good at twisting the throttle rheostat in concert with working the pulse switch so that the transition from pulse to full wave was seamless.
