My neighbor has a Polk subwoofer as part of his home theater system.
Unfortunately any time I transmit with more than 40W of power on any
frequency from 1.8 to 28 MHz, it is audible through the subwoofer.
Working with the neighbor and the local Industry Canada office, we have
found that the field strength is approximately 1.8 Volts/meter.
Every time the transmitter is turned on, the subwoofer thumps and
distorted voices or CW or rtty keying can be heard. We were also able to
repeat the problem using an FRS radio, less than 1 watt of power @
462MHz, in the same room as the PSW12.
We have isolated the problem to the sub. Disconnected from the receiver
with only the AC cord plugged directly into the wall outlet or through
an ICE AC/EMI filter, the results are the same.
We have tried placing snap on ferrite cores (Mix 31 and 43) products
from the Fairite com on the LFE cable and on the AC power cable. No
We have wrapped the power cord around mix 31 torroids for filtering with
Is there any further things than can be done to shield this subwoofer
from RF interference?
Industry Canada says that the amateur station is clean, and operating
within all regulations, is properly grounded and filtered.
Other neighbors with powered sub woofers are not experiencing any
problems. One loaned the affected neighbor another brand product and it
did not receive the interference.
Any suggestions or advice on further things to try would be appreciated.
The neighbor of course does not want to buy a new sub.
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