[RFI] Investigating receive noise - got a few questions

Jim Brown jim at audiosystemsgroup.com
Thu Dec 20 20:02:42 EST 2018

On 12/20/2018 4:24 PM, Andy KU7T wrote:
> (medium impact) my two Trane XL 15i heatpumps. When they run the create nasty spikes on 20 and 15, that are about 20kzh apart and about 5 – 10 db above noise floor. I want to fix this.

Hi Andy,

This is most likely caused by a variable speed motor controller. The 
first thing to try is ferrite chokes on the power cord and any other 
wiring (like a thermostat) leaving the units. If that doesn't fix it, 
you'll need to go inside to choke the cable between the controller and 
the motor. It's also a good idea to call Trane and ask them for a fix. 
Mfrs of stuff like this often have RFI kits. But try the ferrite chokes 
before you spend any real money on them.

Congrats on your excellent work so far.

73, Jim K9YC

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