Topband: Boradband noise on 160 meters tracked down to apartment complex

W2PM via Topband topband at
Sun Dec 14 18:38:09 EST 2014

Sounds like a job for the MFJ nuller. The good news being its a point source and should be easily handled. It may cost you several months of frustration for no good outcome otherwise but perhaps it's worth a try if there is a simple bonding issue there. 

Sent from my iPad

> On Dec 14, 2014, at 01:08, Jim Brown <jim at> wrote:
>> On Sat,12/13/2014 5:35 PM, Don Kirk wrote:
>> Now going back to the contractor that installed the equipment in an attempt
>> to better understand the hardware in the unit
> That smells like a Variable Speed Drive, the heart of which is a switching power supply that generates pulses in the 10 kHz range, the width of which are varied to control the speed of the motor. Lots to go wrong here -- switching power supply, square pulses of big current running a distance between the controller and the motor, often with supply and return conductors widely separated from each other, and with controller and motor widely separated, so the current flows in a large loop. Can you say train wreck?
> 73, Jim K9YC
> _________________
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