MPPT Controller Radio Interference

[witzgall]

HI all;

Our recently installed BZ 500 solar controller is putting allot of noise on certain channels of our radio. What, if any, can I do to suppress this noise?

Chis

[Pblais]

How is it at night? I'm curious how you can conclude that to such a level of detail?

[witzgall]

Paul,

I did think to check the noise at night, but alas, I forgot. It is the same noise that our shore power charger puts onto the radio when it is turned on.

It is there on both the station radio and the hand-held. The noise was not there before we installed the controller (or the new refer, but turning that off does nothing to change the noise). I know that to test conclusively, I would need to pull the fuses on the controller (so it is not powered) but I did not get around to it this weekend, as we were either enjoying ourselves, or doing brightwork.

Chris

Chris

[c.spots]

I have the same controller, and also found interference on few SSB frequencies. No problem at night and the noise goes away when I power off the solar panels. Indeed, I made a point to also install a power switch on the controller for the new solar panels, and the wind generator.

[witzgall]

So would doing something like putting chokes on the power lines help at all?

Chris

[Paul Elliott]

Originally Posted by witzgall

So would doing something like putting chokes on the power lines help at all?

Short answer: It might help, and won't hurt. I would try putting ferrite clamp chokes on any connected cables, as close to the unit as possible. If the wire gauge and length allows it, put a few turns through the choke for more effect. The goal is to keep the wires from acting as antennas.

More chokes will be better, up to the point where the wires are no longer a factor, and any remaining signal is being radiated by the circuitry within the unit. At this point, you may consider building a screened cage, but this can be difficult to do effectively.

[witzgall]

Having never done this, what specifically should I buy, and where? The wire is all 8ga.

Chris

[Paul Elliott]

Chris, I get my ferrite clamp-chokes from a local electronics surplus store (but I'm an electronics geek). I see that Radio Shack has something that looks reasonable:

Snap-Together Ferrite Choke Core - RadioShack.com

These are generally available in larger and smaller sizes. There are different ferrite core materials available, some optimized for VHF interference and some better for HF (SSB) frequencies. It can be hard to get this level of detail for the cores you might find, but any of them should help (if the problem is interference radiating from the cables).

I would buy a handful of the chokes and put them on any cables as close to the device as you can. Use ty-wraps to keep the cores from sliding, and you may want to clamp the cables down to something solid, to keep the heavy cores from stressing the cable connections as the boat rocks and rolls.

If you can make several loops through the core, be sure to pass the cable through the center hole, around the outside of the core, then back through the hole (wire always running in the same direction through the hole). If you run the wire back through the core in the opposite direction it will cancel the choking effect. Of course with #8 wires, you will probably only be able to fit it once through the core.