hi

a while ago i posted hoping to get some ideas how to eliminate
some s9 noise caused by my buildings new elevators

only took them 9months to install some electrical filters but the
guy doing it was very nice and showed me a few things

since the filters didn't help seemingly at all, i wanted to provide
some more information and see what anyone might think would be
either some good tests to make and or further corrective actions

a recap, jan 08 we got a new elevator system the original 1940's unit
was just a rack of relays there are 2 elevators motor and stuff in
a small room rooftop noise was always s0 or s1

the new system i can see is made by galaxy believe it or not made in
the bronx ny i am told they are a large world wide supplier since i
live in the bronx at least they are local

my first look in there today shows they did at least take pride
in there work, all the wiring in there is really nice

there is kinda 2 main parts in the cabinet a large pc board and a
magnetek HPV 600

i took my ft817 shut the other elevator off and moving the rig
around i see i got no interference from the computer board getting
near the magnetek big time noise


they have the manual online
http://www.elevatorcontrols.com/down...les/hpv600.pdf

pretty interesting a section in there on how to mitigate noise
perhaps a few things in there i could maybe double check

when noone is using the elevator they throw out some noise like about
s2 maybe more when the elevator starts moving it jumps naturally
to about s9

i was wondering how to first see where the noise is leaking from
the metal cabinet is pretty think i say double the gague of say a
file cabnet , it does have slits on either side for air a few
holes for conduit which runs to the power and to the motor

they seemed to pay attention to grounding the door had a little
ground wire on it, etc naturally this is all fast first impression
stuff i didn't have a lot of time up there

i thought perhaps painting the cabinet w/rf paint and getting some
screens over the vent slits thou obv that wouldn't help if it's
radiating along the conduit didn't have a chance to measure for that

the magnetek is a bread sized box it gets hot and has a fan so i
can't cover it, but perhaps a perferated copper/lead enclousure might
help?(assuming it's not radiating along its wires)

as a last resort perhaps replacing the magnatek w/another brand known
to be rf quite however i personally don't know how i would find
that out and no garantee they would risk swaping the unit oout



so i am hoping that there might be some brainstorming and thoughts
you all might share?

any advice tips much appreciated


thanks for all