I just saw this firsthand this week - I was out camping and had a Morningstar SureSine 300W inverter inverter setup on the camper to charge a few things, and as Field day was approaching, setup my HF ham radio (running off the same deep cycle battery), adjacent to the inverter. My antenna was up in the trees ~ 40 ft directly above & fed by ladder line (G5RV for those who know). I turned on the inverter & bam, wiped out my radio reception....
So I adjusted my operating time to be opposite the times we needed to run the inverter... -Glenn KA2DTH -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Exeltech Sent: Thursday, June 24, 2010 12:35 PM To: RE-wrenches Subject: Re: [RE-wrenches] AM noise on batteryless inverters RFI (radio frequency interference) from inverters is a fact of life. This is especially true at lower frequencies, such as for AM radio. There isn't a cure-all. Each make and model of inverter will differ in the amount of interference it generates. Steps to reduce the problem also differ. Ferrite cores (mentioned below) may help. These need to be installed around DC and AC leads. Multiple cores on each DC leg are almost always required due to the very low impedance presented by the DC input side of the inverters. Looping AC conductors multiple times through a large ferrite core will also be helpful. Bypass capacitors are also often beneficial when they're connected to the conductors on the battery and load side of the ferrite cores. Ensure all chassis screws are clean and tight. Earth grounding the inverter chassis may help. Experimenting will be needed with and w/o this ground to see which works better. Separate the radio receiver from the inverter as far as possible. Distance is your friend here. Ham radio equipment tends to be less affected by inverter RFI because the receivers are fed with coaxial cable, which is self-shielding. The coax is connected to antennas that are commonly 50-100' or more from the inverter. There are some common steps you can try .. but in the end .. steps unique to the particular site may also be needed. Dan --- On Thu, 6/17/10, Darryl Thayer <[email protected]> wrote: > From: Darryl Thayer <[email protected]> > Subject: Re: [RE-wrenches] AM noise on batteryless inverters > To: "RE-wrenches" <[email protected]> > Date: Thursday, June 17, 2010, 11:30 PM > I have heard that putting small ferrite donuts > around the AC and DC wires will reduce this > noise. Place them inside the inverter. they are > avaiable from DigiKey > Darryl > > --- On Thu, 6/17/10, jay peltz wrote: > > > From: jay peltz <[email protected]> > > Subject: AM noise on batteryless inverters > > To: "RE-wrenches" <[email protected]> > > Date: Thursday, June 17, 2010, 8:35 PM > > HI All, > > > > Say I've had a question from a client about AM radio > > noise from his battery-less inverter. > > > > I'm wondering if there is any other folks out there > > who have found this to be problem? > > > > Now I realize that most people listen to AM in the > > evening when the inverters are non-op so this > > might not be a problem for most people. > > > > Thanks in advance, > > > > jay > > peltz power _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
