Very good comment. All wires are capable of being “transmitting antennas”, even
that little thermostat or relay control wire. And ferrets do more good for hams
than squirrels 😀😀
Sent from my iPhone
> On Feb 7, 2020, at 1:39 PM, <r55stan@gmail.com> <r55stan@gmail.com> wrote:
>
> I was receiving some weak to moderate RFI from my Carrier HVAC unit. I
> installed a line filter and ferrites on the power chord. That helped, but I
> was not satisfied. Then I installed ferrites on the cable to the thermostat
> and that reduced the remaining RFI to extremely faint on a SDR display. Just
> about undetectable. I consider that fixed. The lesson for me on that
> project was RFI can get out of a piece of equipment on EVERY conductor that
> comes out of it. I think we tend to only focus on the power chord because
> for most appliances those are the only wires connected to it. My only other
> comment is a single pass through a ferrite probably won't reduce a strong RFI
> source enough.
>
> Randy KQ6RS
>
> -----Original Message-----
> From: RFI <rfi-bounces+r55stan=gmail.com@contesting.com> On Behalf Of James
> Jordan
> Sent: Friday, February 7, 2020 9:27 AM
> To: Kim Elmore <cw_de_n5op@sbcglobal.net>
> Cc: rfi@contesting.com
> Subject: Re: [RFI] Multi-Stage High Efficiency Air Conditioner Units
>
> Can't be specific on HVAC units, but the Schaffer line filters, available in
> various amperage ratings from Mouser can be inserted in the power circuits.
> Mouser 631-FN2070[ampere rating]. I Use them on Pentair variable speed pool
> pumps at VP5 and they killed very nasty RFI from those motors. I would
> negotiate with an installer of higher quality units (Carrier, Trane) (Avoid
> the cheap Goodman, Coleman, etc.) that if the unit creates RFI that they will
> install appropriate line filters. We have a top end Carrier variable speed
> multi-stage unit and I'm not getting any RFI, but my hamshack is quite a ways
> from it in a detached garage bonus room so it's still possible some is being
> generated.
> Good luck. The high efficiency definitely saves electricity.
> 73,
> Jim K4QPL
>
>> On Thu, Feb 6, 2020 at 11:19 PM Kim Elmore <cw_de_n5op@sbcglobal.net> wrote:
>>
>> My wife has been interested in increasing the efficiency of our air
>> conditioner units. It seems that the only path to better efficiency is
>> multi-stage/multi-speed units. I recall a lot of talk about the
>> horrific RF noise these things generate. Does anyone know of RF-silent units?
>>
>> Kim N5OP
>>
>> --
>>
>> Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM,
>> PP SEL/MEL/Glider, N5OP, 2nd Class Radiotelegraph, GROL)
>>
>> /"A great second violinist plays second fiddle to no one." //– Robert C.
>> Marsh, Chicago Sun-Times./
>>
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>>
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