VHF Interference / Lowrance

[Slabby20]

Has anyone else had a problem with interference (a loud screeching sound on some channels) on their VHF after installation of a Lowrance sounder/GPS with an ethernet connection or after installing a Lowrance Broadband Sounder? I have that problem and thought it was just my VHF going bad. However, I read tonight on another forum that others have had the same problem after installation of new Lowrance equipment with an ethernet connection. They say that they haven't been able to solve the problem by isolating power, checking grounds, etc. and that the Lowrance tech department has been no help. Now I'm wondering if my VHF is actually bad or is it a problem connected to Lowrance. Any thoughts??

 

[SerengetiGuide]

Yeah...happened on our Campion...we couldn't talk on the VHF if the GPS was on...don't have the Lowrance anymore so doesn't happen anymore but it was a pain in the @$$!!!

www.serengetifishingcharters.com

 

[The Fish Assassin]

If they share the same ground at some point, you might want to get a inline noise reducer.

Something like this might definitely help.

Take only what you need.

 

[Slabby20]

quote:Originally posted by The Fish Assassin

If they share the same ground at some point, you might want to get a inline noise reducer.

Something like this might definitely help.

Take only what you need.

Thanks for the suggestion. I'll give it shot before changing out the old VHF.

 

[Gomphus]

Before you go out amd buy a filter to try, disconnect the antenna from the radio and see if the signal from the sounder/gps changes or is reduced in strength. It might be one of the oscillators or circuits in the gps that is emitting an rf signal that is actually getting into the radio through the antenna. If it is then the filter won't help you.

What makes me suspicious is that you said it happens only on some channels. A signal coming through the power leads often will be on all channels.

If it is coming though the power leads you may also want to run the power cable for the radio right back to the battery. The battery acts as a big capacitor and can reduce the interference.

 

[Slabby20]

Thanks Gomphus,

That's easy to test. If it ends up being a RF signal from the GPS is there anything that can be done or am I just s#@t out of luck?

 

[PW_Homer]

Good dicusssion on this here

http://www.thehulltruth.com/forums/thread-view.asp?tid=224505&start=1

I am also having the same problem and trying to solve it. I will keep watching for a solution. Hard to here anything on my VHF when trolling. Sucks

At times also the unit seems to take forever to lock/read bottom especially at 50HKZ. I found that the 200HKZ works much better than the 50 and reads fine at 35MPH at 600' .I am using an Airmar B60 thru hull. I am planning on buying a switch so I can see how much difference there is will the stock unit supllied by Lowrance compared to the Airmar. It is attached to a LCX38C and also networked to the LMS 525DF. I am starting to wonder if it is caused by the 2 networked. Boats stored for the winter so on my list to resolve come March

 

[Slabby20]

I'll be going to the Seattle Boat Show in a week. I'll check with the Lowrance booth and see what they say. After reading the link you gave I'm not real optimistic. Maybe they should just trade us a new unit with built in Broadband Sounder for our current units that create interference. They should have to do something about it since the units they sold us are putting out the interference. Not having a working VHF is dangerous!!! I guess that if I'm sinking I just need to disconnect my Ethernet cable first before using the VHF

 

[PW_Homer]

I did some more testing today (Could not leave it alone) and the static is from the BBS. It is not the VHF or the GPS/FF. The BBS is updated to the lastest firmware as well as both GPS/FF
Boat is in my hard so no motors running or anything else.
1- Turned on VHF - no static
2 - Turned on LMS525 (connected to network, no transducer connected,GPS signal from network, unit only used for GPS and other info from network and backup)- VHF - no static
3 - turned on LCX37c - unit connected to network, BBS disconnected -VHF - no static
- connected BBS to unit - major static and high pitched noise
- turned off LMS525 - same noise
- diconnected LMS525 from network - same noise
- switched units - now using BBS thru LMS525 - same noise

As long as the BBS is in the equation no matter how its connected it kills the VHF. Both GPS/FF units do not affect the VHF no matter how connected, but add the BBS into the picture and render my VHF useless.

I say replace both my BBS and LCX37c with the new HD unit as the cost is/was the same. The LCX also looses all map detail at times (It will just show the yellow map and water with no details like grid lines, depth - and to make it work I have to zoom out and in again to get the details back, I also swapped the Nav card from the other unit and the same happens)The LMS works fine. I will call Lowrance this week and will update

 

[Slabby20]

Went to the Seattle Boat Show today and talked to the Lowrance reps. the first two guys I talked to in the booth said they had never heard of the problem. Then the head Lowrance guy came back to the booth and right away knew the problem we're talking about. He said that there had just been a big conference call about it last week and that Lowrance now knows there is a big problem. He said their engineers are working on the problem and trying to find a fix. He also said they'll get the word out when there is a fix. We'll see what happens.

 

[PW_Homer]

Did some more testing today. Reading the forums they thought it might be the VHF attenna. Well for me for sure it is not.

I had the VHF off and then powered on the BBS, once I started up the LCX37c I started hearing a pop/crackle sound from the VHF very odd. I then turned every thing off and disconnected the VHF attenna and powered everything on and the popping sound started from the VHF. Turning on or off the LCX made the VHF start to make pop/crackle sound. Without the BBS all is fine.

 

[Slabby20]

PWH,

I've doone everything you have with the same results. No question it is the BBS and/or ethernet cable. From what I heard yesterday at the boat show from Lowrance there is no fix right now. Their engineers will be working on a solution. They better come up with a solution soon because we all need a working VHF for safety reasons.