I spoke to a very knowledgeable support person at Advance Ballast
www.advancetransformer.com about a little “pill-bottle” tester that I thought they gad offered for testing filament voltage at two-pin tombstone sockets. She said Advance prefers using true-RMS voltmeters, but that she knew that Universal {their competitor!} had offered some testers, and suggested calling them.
www.universalballast.com/techSupport/troubleshooting_guides/lin_a.htm describes a bi-pin-base tester for 30- and 40-watt-rapid start fixtures and a recessed-double-contact base version for 800/1500ma fluorescent fixtures. The HO model was called a “CT-8” but they have discontinued selling both in the last six months, according to an experienced phone-support guy there.
If I had to work on many rabid-start or HO ballasts, I would probably make up some test bases from discarded tubes with extension leads for a meter. {Acceptable filament voltages are listed in pdf troubleshooting guides.} Both companies’ support folks warned that the flashlight-lamp test procedure was OK for linear and electronic ballasts, but to be sure and use a true-RMS meter on high-frequency electronic ballasts for accurate results.
Both reps motioned that a good reading of filament voltage at both tombstones {or four for two-lamp ballasts} did not automatically mean that the fixture should work OK, but implied that if you didn't measure good filament voltages, there is no point in troubleshooting further.
[This message has been edited by Bjarney (edited 09-04-2003).]
