Again, this is due to special equipment they had when DL was first built, remember nothing like this oarkbexiated at the time, so a lot of so called standards were established on the fly and yes frequency did vary. I dont remember the exact number, but some of the staff that have worked shows or janitorial fir more than 40 years or so should be able to tell you more details.Thanks for your response and that much makes sense.
I think it was the "voltage and frequency" (freq doesn't change) part that was throwing me!![]()