997 woes.........

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03-04-2008, 05:53 PM
Cane Pole

997 woes.........

Garmin 240 puts snow on the humminbird screen. Turn 240 off Humminbird clears up. Why don't the Humminbird interefere with the Garminc 240?

With the Garmin 240 off, crank the big engine up, the snow appears.

All electronics are on an electronics only battery.

I think there is noise coupled in the wiring from the batteries/transducer/etc. to the cockpit because of wires being parallel in the cable channel.

Impossible to separate wires via the cable route.

Rule of thumb. Signal wires should not run more than 12 inches in a parallel path to power wires and should be separated by at least 6 inches.

Any suggestions?

By the way folks, in electronics there are all sorts of thumb rules.:)
03-04-2008, 06:01 PM
WarrenMN

Can you get one of those circular ferrite chokes you wrap you power line around a couple times? That or slap a big capacitor between the leads. wonder if they still sell the power line filters at Radio Shack?

WarrenMN
03-04-2008, 06:05 PM
Cane Pole

Quote:

Originally Posted by WarrenMN

Can you get one of those circular ferrite chokes you wrap you power line around a couple times? That or slap a big capacitor between the leads. wonder if they still sell the power line filters at Radio Shack?

WarrenMN

It have considered these, but haven't tried it yet. Not much room to work with.

I don't know what size ferrite I really need. Size matters here. This is not my area of expertize.
03-04-2008, 06:16 PM
Barnacle Bill

Tom I use some similar to this: http://www.radioshack.com/product/in...entPage=search

I also make my own twisted pair wire for power. Home run from the battery to the units. The only interference I get on my Lorances is when I get in deeper waters.
03-04-2008, 06:24 PM
Cane Pole

Quote:

Originally Posted by IBNFSHN

Tom I use some similar to this: http://www.radioshack.com/product/in...entPage=search

I also make my own twisted pair wire for power. Home run from the battery to the units. The only interference I get on my Lorances is when I get in deeper waters.

I have seen those.

Twisting the power wires is an excellent idea. I doubt if the Humminbird power cable is twisted pair. I could do this, but what a beach. I guess I will try the ferrite if I can get it close enough to the head unit.
03-04-2008, 07:50 PM
WarrenMN

I dropped an email to Lind Electonics, http://www.lindelectronics.com/ , to see if they had some thing that could filter and regulate at 13.2v. They make a good DC DC power supply that can take a range of voltage and keep it at what its designed for. I always use them on my laptops and the ones I help other people set up for their own use. I'll post when they answer.

WarrenMN
03-04-2008, 08:05 PM
ShilohRed

Theres a setting that will allow the unit to take care of that.I do not have may owner manual here. but its in it.
Pete
03-04-2008, 08:12 PM
bigfish5

I Had A Similar Problem And I Ran A Separate Ground Wire And It Solved My Problem. I Know It Doesnt Make Since But It Worked. My Unlce And Brother Are Both Electricians And They Said It Was A Waste Of Time And Wire. But I Tried It Anyway. They Could Not Believe It Worked. I Dont Know Why But Dc Items Do Weird Things Sometimes. Its A Cheap Try.
03-04-2008, 09:08 PM
jaxsprat

To bigfish 5, & canepole On the sidefinder site when many folks were complaining of interference from trolling motors the first fix they always recommend is running a separate ground wire from troller back to battery seems it has worked for most. Just know what I read, not to kean on electronic stuff :) Of course he may have two different problems, one the Garmin transducer,just like Lowrance causes interference, and 2 the big motor.
03-04-2008, 09:14 PM
Cane Pole

Quote:

Originally Posted by ShilohRed

Theres a setting that will allow the unit to take care of that.I do not have may owner manual here. but its in it.
Pete

Filter settings. Didn't fix it.
03-04-2008, 09:17 PM
Cane Pole

Quote:

Originally Posted by WarrenMN

I dropped an email to Lind Electonics, http://www.lindelectronics.com/ , to see if they had some thing that could filter and regulate at 13.2v. They make a good DC DC power supply that can take a range of voltage and keep it at what its designed for. I always use them on my laptops and the ones I help other people set up for their own use. I'll post when they answer.

WarrenMN

good stuff. I got one for my Motion Computing tablet.
03-04-2008, 09:21 PM
Cane Pole

Quote:

Originally Posted by jaxsprat

To bigfish 5, & canepole On the sidefinder site when many folks were complaining of interference from trolling motors the first fix they always recommend is running a separate ground wire from troller back to battery seems it has worked for most. Just know what I read, not to kean on electronic stuff :)

Electronics has its own separate battery. Not on engine start battery or trolling motor battery. I believe the noise comes from the cable routing.
03-04-2008, 10:21 PM
PanMan_VA

Could you wrap the transducer and power cables for the 997 that run parallel to the other power wires separately in aluminum foil and ground them?

I ran the transducer cable in the same channel as the other power cables running from the transom to the console and do not have any problems. When running both the Lowrance and 997 at the same time, I get a small amount of interference on the Lowrance and no interference on the 997.
03-04-2008, 10:28 PM
Barnacle Bill

Quote:

Originally Posted by PanMan_VA

Could you wrap the transducer and power cables for the 997 that run parallel to the other power wires separately in aluminum foil and ground them?

I ran the transducer cable in the same channel as the other power cables running from the transom to the console and do not have any problems. When running both the Lowrance and 997 at the same time, I get a small amount of interference on the Lowrance and no interference on the 997.

I use to have about 100' of 16 gauge audio cable made that way. We used it for wiring speakers for paging systems attached to our phone system. Made great power cabe.
03-05-2008, 11:12 AM
Joby @ Humminbird

Cane Pole,

Can you take a snapshot of this and email it to me directly. My email addres is [email protected]. I would like to see this.

One question are you running both the Garmin 240 and the 997 at the same time.
03-05-2008, 06:20 PM
Cane Pole

Quote:

Originally Posted by Joby @ Humminbird

Cane Pole,

Can you take a snapshot of this and email it to me directly. My email addres is [email protected]. I would like to see this.

One question are you running both the Garmin 240 and the 997 at the same time.

Yep. The Garmin and 997 on at the same time. Only occurs when side scanning. Odd, since such difference in frequencies. Cut Garmin off, SI clears.

Be couple of weeks before we go back to lake. I will try to remember. Remembering things isn't one of my stronger points anymore. But I will definitely try.
03-05-2008, 11:35 PM
hays47

Canepole : Been 40 some years for me since my electronics schooling. Seems to me I rmember something about " harmonic frequencies ". Whereas 60hz would be a harmonic of 360hz 120hz 600 hz . Noise is usually displayed in an electronic circuit as " snow ".
Noise is normally overamplification of a transient signal that causes the intrinsic design of said circuit to malfunction.

Early TVs had a noise filter circuit in them to supress transient induced voltages or redirect them to ground. Try some sort of shielding between the Garmin wires and the Humminbird. Ground shielding at both ends.

Moral of story : Engineers may design a circuit but it takes a tech to make her work.
03-06-2008, 01:01 AM
ShilohRed

Quote:

Originally Posted by Cane Pole

Filter settings. Didn't fix it.

Your luck is like mine.
Pete