VHF has inteference from FF?

[Chris1956]

I installed a new VHF Radio in my boat yesterday. The owners manual for the radio claimed it was "virtually Immune to ignition noise". I haven't tested that claim yet, but my fish finder sure puts some noise onto it. Is this unusual? Is there a way to reduce/eliminate the ff noise?

BTW the FF is made by Apelco (Raytheon)and has dual transducers, 50KHz and 200KHz. The power for both runs thru the same accessory switch. if I seperate them (two different switchess) will that help?

 

[PondTunes]

Re: VHF has inteference from FF?

Giving them two different power sources might help, check to see that your radio wiring, ie antenna or speaker outputs are not running parallel with the fish finder transducer leads.

A coil of wire will also generate much more electromagnetic interference than wires that are just run straight, fishfinder leads are normally quite long and the instructions always say to not cut the leads.. Ensure that this coil of extra wire is as far away from the electronics in the radio as possible as well as your antenna lead.


You can probably move the transducer wires around or the antenna to the radio and see if the sound changes/goes away. If they are run together/wire tied that is probably the source of your problem.

 

[bruceb58]

Re: VHF has inteference from FF?

First thing I would do is to see if it is comong through the power or through the antenna.

Remove the antenna connector and ground the center conductor to the shield at the radio. If you still have interference, it is more than likely coming throught the power. You could also wrap aluminum foil around each unit to see if that helps. If it does, it is a poor design issue on one of the units and will be tough to solve.

For power to the VHF, run a twisted power ground pair all the way back to the battery with a fuse at the battery. Run the line far away from other wires, especially the transducer cable for the fishfinder.

 

[Texasmark]

Re: VHF has inteference from FF?

Raytheon has been building radio's(and still is) since before Jack Benny was a gleam in his dad's eye. I doubt seriously that there is a design issue with the radio.

The common power will probably turn out to be your problem.

Bruce put you onto the right answer.

Mark

 

[bruceb58]

Re: VHF has inteference from FF?

I doubt seriously that there is a design issue with the radio.

I would probably agree with that.

Raytheon is no longer involved in the marine business. They sold their stake in that long ago...probably 6 years or so. The current company, Raymarine, has nothing to do with Raytheon.

Any new designs are done by the new company...Raymarine.

 

[Texasmark]

Re: VHF has inteference from FF?

I must have missed that. The last stockholders meeting I attended showed posters of marine electronics; on privately owned watercraft.

Mark

 

[bruceb58]

Re: VHF has inteference from FF?

When was this stockholder meeting?

I used to be a Raytheon employee and have a lot of stock in Raytheon still. I now work for a spinoff of Raytheon. Haven't seen anything mentioned in the annual report for awhile.


Here is why:


http://www.raymarine.com/raymarine/Default.asp?site=1&SECTion=1&page=1323

"Raymarine enjoys a strong history of delivering innovative products to the marine electronics market. Formerly existing as the Recreational Marine Division of Raytheon (NYSE: RTN), Raymarine was formed as a company in 2001 after a management buyout, which included the rebranding of all products. "

 

[danmcg]

Re: VHF has inteference from FF?

Sounds like you have a shielding issue with one or both devices. Unscrew the antenna from the back of the VHF radio and see if the noise goes away. If it does, the unwanted noise is being received through the antenna. Try relocating the antenna. If the noise is still present with the antenna line unplugged, try relocating the radio farther away from the fish finder.

 

[Texasmark]

Re: VHF has inteference from FF?

I guess it's been awhile. My how time flies.

Mark

 

[bruceb58]

Re: VHF has inteference from FF?

I guess it's been awhile. My how time flies.

Mark

Isn't that the truth!

I used to get employee discounts on the Raytheon electronocs...no longer!