inverter rfi problems

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kato
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inverter rfi problems

Post by kato » Tue Mar 05, 2002 9:36 am

I power my house and work shop with a trace 5500 watt inverter.
I also enjoy ham radio and swl as hobbies, what can I do to cut down on the huge amount of rfi the inverter throws of drowning out most of the AM bands.
the inverter is 20 feet away in the garage, but it seems that no matter where in the house I am, the wiring in the house seems to be giving off huge amounts of rf interference.
the system is a true sine wave trace 5500 watt inverter with two 48 volt battery banks made up of L-16, 6 volt deep cycle batteries.
I have the neutral of the inverter(120 volt side) grounded (bonded ) in the service panel, and tied to a ten foot 5/8s ground rod right next to the service, what else can I do?
Every one has some one in their family who is crazy,
If you don't know who it is, it's you.

russlk
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Re: inverter rfi problems

Post by russlk » Tue Mar 05, 2002 2:42 pm

A power line filter at the inverter output is what you need. It is difficult to find any greater than 30 amps in a stock item, but you could parallel units for more current. Digikey.com has a 30 amp filter for $35.98 or a better model for $66.00. Part numbers: 364-1030-nd and 364-1045-nd.

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Externet
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Re: inverter rfi problems

Post by Externet » Tue Mar 05, 2002 3:38 pm

Hello.<p>The interfering noise can reach your amateur radio equipment via the house power lines or via antenna; or both. You must find first the offending path to tackle the problem.
Try operating the HF radio with an automobile battery with no connections at all to mains.
If you still get the noise, then it's time to shield. Shield what ? The inverter ? or the radiating mains wires inside walls; or both ? Good luck on that...
Try to contact the inverter manufacturer, they may have some fixes.<p>Those compact fluorescent light bulbs being used in my apartment building killed my amateur radio hobby by being very noisy. Interference spreads everywhere.<p>That's why amateur radio equipment and high fidelity stereo systems do not use switching power supplies.<p>You have a though one, hope this gives you a clue.<p>Miguel
- Abolish the deciBel ! -

HomeBrew
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Re: inverter rfi problems

Post by HomeBrew » Wed Mar 06, 2002 1:55 am

I agree with the filter solution. I power my shop with inverters and have the same problem with my AM radio and a TV I use. The larger filters seem to do a pretty good job if you are far enough from the inverter itself, but you may still have a little hash on the AM bands as they are prone to pick up all kinds of noise. You might give it a try to see if it will reduce your noise to an acceptable level since sheilding probably isn't a easy task after you get away from the inverter itself. Just be sure to place the RFI filter as close to the inverter output as you can in order to minimize radiation from the wiring. Good Luck !!

Alan87I
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Re: inverter rfi problems

Post by Alan87I » Wed Mar 06, 2002 4:44 am

For interferance leaking from the inverter it's self . Try making a cage with strans of copper wire and wood . Similiar to a rabbit cage in design , as long as you keep the wires at least 2" apart. So you will have 2 inch squares, the frequencys that will escape should not affect your radio. Ground the cage to a new rod as faw away as possible . Try a hand held CB with a coax attached , 3 feet . make a loop with the center wire about the size of an orange and connect it back to the braid . Works good for finding interferring frequency sources. Allan

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