I remember one such room back in the mid to late 1970s; actually it was almost a floor in itself, as opposed to a room. Four huge Westinghouse traction motors, each with its own rotary converter, handled 11 floors. Racks with hundreds of microswitches and a moving panel followed the cab's progress and controlled the movement. A relay wall continuously clacked and sparked as buttons were pressed. We always wanted to figure out which relay to kick closed as we were leaving, to call one cab to the top floor so it would meet us there.
There were several other pieces of radio equipment in the same area, including some government stuff, although theirs was located in a corner by the stairway and nowhere near the actual elevator stuff. Other than the constant clicking and whir of the MG sets, the noise wasn't that bad. I have more annoying noise from the fans in a 20kw FM transmitter at my UHF repeater site than was present in that old elevator room. Hearing protection? What's that? I doubt that the RF would have had any effect on the 120/240V DC relays used by the old Westinghouse system, but I can see how today's solid-state logic could be bothered by enough nearby RF. Maybe the NEC regs changed in the last 30 years. I think all the radio stuff eventually got moved to another building. Bob M. ====== --- "Steve S. Bosshard (NU5D)" <[EMAIL PROTECTED]> wrote: > In Texas the JCAH (Joint Commission on Accreditation > of Hospitals) > guidelines forbids installation and operation of > radio transmitting > equipment in hospital elevator equipment rooms. > Both Scott and White > and Kings Daughters Hospitals had us re-locate all > of their radio > equipment in the early 90s.. Coaxial cables still > run through the > elevator rooms, but there is no radio equipment > installed therin. As > earlier stated graphite from the motor brushes along > with noise from > relay contactors and now SCR/Triac control is not > nice to say nothing of > the ambient noise in the rooms - had to wear > headphones to hear a > receiver, make such installations unpleasant at > best. I believe the > reasoning was RF emissions possibly affecting > elevator controls. > > Steve NU5D __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
