Bob
Since you get noise on a handheld radio, I assume that the noise is not resulting from hash on your 12v DC lines. It sounds like the battery monitor is radiating. If the RFI is directly from the battery monitor, there is little that you can do. By federal law, the manufacturer is required to build and sell stuff that doesn’t radiate, but many manufacturers don’t understand RFI and have no clue how to reduce it. It takes a degree in EE and black magic to get RF noise down. If you can put the stuff inside a metal enclosure you might reduce noise, but chances are you can’t do this.

You might get a copy of the ARRL handbook and read the section on EMI. If you don’t want to purchase the book, you can probably borrow a copy from your local library.

Hope this helps
Regards
Rich – KE1EV

Bob,

I have exactly the same system on my boat and lots of radios. No RFI
problem from the Xantrex 2000.

There are two types of rfi: conducted and radiated. Most of the
problems found on boats are of the conducted sort. This means it is
carried by the power lines (conducted back down the power lines) and not
through the air. The good news is that conducted rfi is easiest to
fix. The fix is typically installing ferrite chokes on the wires close
to the source device and on the power supply wires to each radio.
Donuts and clamp-on chokes are easy enough to find and experiment with.
Here is one article that might help you out:
http://www.hamuniverse.com/rfi.html One good source of inexpensive
ferrites is allelectronics.com

One thing worth noting is that I installed big EMI power filters on my
ham radio and have not rfi problems. These are cheap if you get them
from a surplus supplier. For example:
http://www.excesssolutions.com/cgi-bin/category/11800

Good luck,

Pete

Robert Fine wrote:

Hi All!

Somewhere back in the dusty archives of this mail list, I’ve described
or recommended my Xantrex 2000 battery monitor and Freedom 2000
charger/inverter to manage the batteries when connected to shore power.

Since day 1 the Xantrex 2000 controller has cause medium to severe
radio frequency interference (RFI). This is so bad that I need to go
to the bow sometimes to use the handheld radio. Now the interference
is affecting the main radio making the lower channels unusable. These
are channels like 16, 13, 10, and oddly 68-72.

How do I know it’s this device? When listening to the interference
and pressing various buttons I get changes in the tones. When I
disconnect the device, the interference goes away. I can also trace
the tones using the handheld’s antenna (point towards device volume
goes up, away, down – move towards volume up, away, down. You get the
idea.)

Now here’s the thing. I like what the device does, but obviously not
the RFI. The RFI happens on shore power or on battery power. I’ve
tried grounding the metal case, putting a ferrite core around the
wires, and contacting Xantrex (response: “Huh?”).

Obviously any antenna wires around the device are shielded. Maybe I
should change them? Or make sure the shield is grounded?

I’m hoping there are members out there who have had a similar problem
and have come up with a simple solution.

Oh, by the way, the interference doesn’t affect the FM radio. (Forget
the AM radio. But that’s not surprising.)

Thanks for any help.

Bob

—
Bob Fine
s/v Pelican
Hull #8

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Bob,

The pin-out on the “satin” cable is different than that of a CAT 6E LAN cable. The “satin” cable is a straight through cable but a LAN cable has different pinouts. To my recollection, that is a 4-conductor RJ11 connector (aka RJ14) where as a LAN cable is an RJ45.

position RJ25 pin RJ14 pin RJ11 pin Pair T/R ± Cat 5e/6 colors Colors Old colors 1 1

3 T + http://en.wikipedia.org/wiki/File:Wire_white_green_stripe.svg white/green http://en.wikipedia.org/wiki/File:Wire_white_green_stripe.svg white/green http://en.wikipedia.org/wiki/File:Wire_orange.svg orange 2 2 1
2 T + http://en.wikipedia.org/wiki/File:Wire_white_orange_stripe.svg white/orange http://en.wikipedia.org/wiki/File:Wire_white_orange_stripe.svg white/orange http://en.wikipedia.org/wiki/File:Wire_black.svg black 3 3 2 1 1 R – http://en.wikipedia.org/wiki/File:Wire_blue.svg blue http://en.wikipedia.org/wiki/File:Wire_blue_white_stripe.svg blue/white http://en.wikipedia.org/wiki/File:Wire_red.svg red 4 4 3 2 1 T + http://en.wikipedia.org/wiki/File:Wire_white_blue_stripe.svg white/blue http://en.wikipedia.org/wiki/File:Wire_white_blue_stripe.svg white/blue http://en.wikipedia.org/wiki/File:Wire_green.svg green 5 5 4
2 R – http://en.wikipedia.org/wiki/File:Wire_orange.svg orange http://en.wikipedia.org/wiki/File:Wire_orange_white_stripe.svg orange/white http://en.wikipedia.org/wiki/File:Wire_yellow.svg yellow 6 6

3 R – http://en.wikipedia.org/wiki/File:Wire_green.svg green http://en.wikipedia.org/wiki/File:Wire_green_white_stripe.svg green/white http://en.wikipedia.org/wiki/File:Wire_blue.svg blue
RJ45 Pin # Wire Color
(T568B) Wire Diagram
(T568B) 10Base-T Signal
100Base-TX Signal 1000Base-T Signal 1 White/Orange Transmit+ BI_DA+ 2 Orange Transmit- BI_DA- 3 White/Green Receive+ BI_DB+ 4 Blue Unused BI_DC+ 5 White/Blue Unused BI_DC- 6 Green Receive- BI_DB- 7 White/Brown Unused BI_DD+ 8 Brown Unused BI_DD- Straight-Through Cable Pin Out for T568B

Robert Fine wrote:

Correction: I misspoke. If it is an RJ-45 connector on the Xantrex, the lan cable should work. (But I recall it to be an RJ-11 connector). (Both the “phone” and the “lan” cables are straight-thru, pin-for-pin cables).

Pete

Pete Dubler wrote:

good luck. Let us know what you learn.

Pete

Robert Fine wrote:

Hi Pete,

Thanks for the info – I’m pretty sure it’s radiated RFI. Here’s why:
Today the Xantrex 2000 for some reason locked up. No RFI. I reset it
by powering it down and up (remove and replace fuse). Hey, Presto!
RFI is back.

There is already a ferrite core on the sensing cables – it did nothing
to help the problem.

I only thought of replacing the control cable because it’s too long by
many feet and it sits coiled next to the Freedom 2000. Now, follow my
thinking here: Even though a cat 6 or cat 5 cable has too many
conductors, it is randomly twisted – I can make one with two pairs and
a shield that I’ll connect to the Xantrex case. By taking two pairs
and switching the ground of the pair you’ll end up with a straight
thru cable that stops near-end crosstalk.

Also, by making it the appropriate length, that’s a help, too, as
there’s no coil antenna laying about.

That all said, though, the strongest signal is at the Xantrex itself.

So, I’ll be experimenting. I may just try grounding the Xantrex case
and see what happens.

Thanks again!

Bob

—
Bob Fine
s/v Pelican
Hull #8

Post generated from Pearson424 Forum using Mail2Forum

Sounds like the case was not well grounded. Congrats on tracking it down.

Pete

Robert Fine wrote:

Hi Pete,

You’re gonna love this.

I went to Radio Shack and got a couple of ferrite cores to put on the
lines right next to the Xantrex. No joy. So I opened the case to see
if there was something I could see (feel) that I could point to to the
Xantrex people.

Also, no joy.

But one of the posts that holds the cover to the unit was loose. I
tightened it and checked the other tight and hey! Presto!
Interference dropped below that of the regular background noise on the
radio. I checked with my handheld. Also good.

Just to be sure I’ve got it, I’ll check again tomorrow, but this is
the best it’s ever been.

Bob

—
Bob Fine
s/v Pelican
Hull #8

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