Dear Frank,
You got my attention! I will correct my mistake right away.
W9IP
-----Original Message-----
From: Frank W3LPL <donovanf@starpower.net>
Sent: Friday, October 20, 2023 3:26 PM
To: Rfi List <rfi@contesting.com>
Cc: nlsa@nlsa.com; Mike Martin <mike@rfiservices.com>
Subject: Re: [RFI] Filtering 220VAC : Success
Please be very careful about applying W9IP's experience before his good advice
causes major property loss or someone gets badly hurt or worse...
Capacitors must never -- must never! -- be connected to AC mains unless they
are clearly marked as X-Class or Y-Class.
No exceptions! Human life is at stake!
Capacitors not clearly marked as X-Class or Y-Class must never --must never!--
be connected to AC line voltage. They must -- must! -- be behind a fuse or
circuit breaker or other suitable AC line protection device.
No exceptions! Human life is at stake!
Capacitors connected between AC line voltage and the AC neutral line must --
must! -- have self-healing properties in case of arc-over.
Acceptable capacitors are always very clearly marked as X-Class,
Capacitors connected between AC line voltage and ground must -- must-- use a
capacitor that will never -- will never! -- fail as a short circuit from AC
line to ground, which can compromise safety and human life. Capacitors
designed for safe connection between AC lines and ground are always clearly
marked as Y-Class
Safety first. Please!
73
Frank
W3LPL
On Fri, Oct 20, 2023, 2:32 PM <nlsa@nlsa.com> wrote:
> Dear friends,
>
> After re-winding the 3-core toroidal choke and adding some 1,000pF
> bypass capacitors to the AC input and VFD output, there is virtually
> no increase in my noise floor when the elevation subsystem is powered
> up. Maybe 0.1-0.2 dB but I can't be sure.
>
> It appears that my EME system* has almost zero self-inflicted noise.
> Six weak spurs in the range 144.1-144.150 MHz. I'm happy.
>
> W9IP
>
> * (7) Raspberry Pi 3B
> (1) Intel NUC
> (1) Netgear ethernet switch
> Anan SDR, Homebrew: transverter, 1.5kW SSPA, TX polarity
> switch, and LNA
> Mitsubishi VFDs for Az & El
> APC switched rack PDU
> ... and their SMPS (no wall warts however)
> ...all mounted in the EME antenna's near field and controlled
> over fiber
>
>
>
>
> -----Original Message-----
> From: RFI <rfi-bounces+nlsa=nlsa.com@contesting.com> On Behalf Of Don
> Kirk
> Sent: Friday, October 20, 2023 7:24 AM
> To: jim@audiosystemsgroup.com
> Cc: Rfi List <rfi@contesting.com>
> Subject: Re: [RFI] Filtering 220VAC
>
> Hi Jim,
>
>
> You said "The neutral is NOT run to a 240V outlet, only the two phase
> (hot) conductors and green" and I think there needs to be a little
> clarification, especially for those that might be dealing with outlets
> that feed Ranges or Dryers.
>
> Back in the late 80's or possibly early 90's NEC required that for new
> construction 220 volt outlets for Ranges and Clothes Dryers must be 4
> wire outlets (2 hot wires, Neutral, Ground) whereas before that time
> 220 volt outlets for Ranges and Dryers were normally 3 wires (2 hot
> wires and Neutral). Notice I said 3 wire 220 volt outlets used a
> Neutral (not ground), but in function there was very little difference
> since the Neutral eventually does tie back to ground in the panel box.
> I'm not an expert on the NEC rules so I don't know what if any additional
> changes have occurred.
> I do believe there is an exception (Grandfather Rule) to the 4 wire
> outlet situation if you buy a modern Range or Dryer if your house was
> built with a
> 3 wire 220 Volt outlet that allows you to use a conversion kit or
> follow instructions provided with the appliance that ties the Neutral
> and case Ground back together in the appliance.
>
> I only mention the above because I was recently asked about it by a
> friend who purchased a new Range and his house was an older home
> equipped with a 3 wire 220 volt outlet so the information is still somewhat
> fresh in my mind.
>
> Just FYI, and 73.
> Don (wd8dsb)
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