I am staying on 14 th floor of a high rise apartment building in Bombay, India.
I have installed di pole antenna for 40,20 and 15 meters in the terrace of the
apartment complex which is on 22nd floor, the coex to my amateur radio rig(
Yaesu FT 847) on 14th floor is abt 35 meters in length.
I am getting a continuous rf interference on all the bands. the strength varies
from S5 to S7 thus drowning out many of the dx signals. On checking using a
portable sony icf-sw7600 receiver and with the help of some senior hams, we
have tracked the problem to the newly installed high speed electronically
controlled elevators. the sound is emanating from the control panels(3 of them)
located on the 24th storey machine room of the elevators.
When all the three elevators are not in use, there is no noise either on my rig
or on sony radio. However as soon as one elevator starts, the noise in the rig
begins, it sounds like something is rotating and noise stops as soon as that
particular elevator stops on any floor .Since at any given moment one or other
elevator out of the three elevators is in motion , there is practically a
continous noise observed on the rig.
I have checked with the portable sony radio, the noise at different distances
from the control panel room (machine room) from 10 feet to nearly 200 feet, but
the rfi continues to be of the same strength.
I have brought this to the notice of elevator manufacturer as well as the
contractor who installed it, and have demonstrated to their technical
represantative the actual rfi coming in to my rig, however they are a bit slow
in rectifying the problem since there are no strict rules or standards in India
on EMI( rf interference) in electronic equipments.
Pending any action by the elevator manufacturer I wonder if I can install any
equipment around my rig to cut down this noise if not totally eliminate it. I
am told there are some noise cancellers available but some hams say that it
may work or may not work.
I would appreciate from members any advice, guidance and solution to this rf
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