I am an engineer working for a local radio station. One of our
transmitters has a repeating problem. For no apparent reason, it shuts
itself down, and the fault monitor indicates that an arc has occurred
at the transmitter's built-in arc gap. These appear to be nuisance
problems, as a thorough search has revealed no faulty components, and
the transmitter resets and goes back on the air when an operator
acknowledges the error. It will then run for several hours before the
problem repeats.

I have noticed that the transmitter uses an unusual arc gap design, unlike any of our other units. The other transmitters use the traditional round ball style arc gap. This transmitter uses a pipe and point arc gap. I have constructed these diagrams to better illustrate the problem.

Top View http://bayimg.com/hajGBaAbm

Side View http://bayimg.com/HAjgAAabM

It should be noted that the dielectric is ordinary atmospheric pressure air, of varying temperature and humidity. The arc gaps are set to the original manufacturer's specifications. Unfortunately, the manufacturer has since stopped supporting this model transmitter.

Is the arc gap distance too small? Or is this arc gap design prone to problems? None of the other transmitters have this problem. Any help would be very greatly appreciated. Thank you for your time.

I have noticed that the transmitter uses an unusual arc gap design, unlike any of our other units. The other transmitters use the traditional round ball style arc gap. This transmitter uses a pipe and point arc gap. I have constructed these diagrams to better illustrate the problem.

Top View http://bayimg.com/hajGBaAbm

Side View http://bayimg.com/HAjgAAabM

It should be noted that the dielectric is ordinary atmospheric pressure air, of varying temperature and humidity. The arc gaps are set to the original manufacturer's specifications. Unfortunately, the manufacturer has since stopped supporting this model transmitter.

Is the arc gap distance too small? Or is this arc gap design prone to problems? None of the other transmitters have this problem. Any help would be very greatly appreciated. Thank you for your time.