[RFI] Multi-Stage High Efficiency Air Conditioner Units

[K9MA]

Most likely the compressor, just because it's larger.

73,
Scott K9MA


On 2/8/2020 12:26, Kim Elmore wrote:
> My understanding is that the RFI is generated by the variable speed 
> motor controls. In these systems, both the compressor and the 
> forced-air run at variable speeds. Which is the main contributor to 
> the RFI? These units will be maybe 30 ft from my tower; I shunt-feed 
> my tower for 160 m, so they will be in a relatively high RF environment.
>
> *IF* we replace our current units (and that's a *very* big if), I'll 
> make sure that the thermostat line is also filtered one way or the other!
>
> Kim N5OP
>
> On 2/7/2020 3:44 PM, Jim Brown wrote:
>> On 2/7/2020 1:11 PM, krgoodwin at comcast.net wrote:
>>> The culprit was the thermostat line
>>> (4-conductor) where installing an RF filter (LC circuit) on each of 
>>> the four
>>> conductors in addition to some ferrites on the line easily solved the
>>> problem.  Next re-install I will put in a shielded multi-conductor
>>> thermostat control line which was my baseline for the house LAN 
>>> (shielded
>>> ethernet line).  Shielded cat XX (ethernet) line costs more but I 
>>> think the
>>> cost is worth it since my tower/beam is right next to the house
>>
>>

-- 
Scott  K9MA

k9ma at sdellington.us