VHF making a popping noise with new stereo

M

mrsrobinson

Well-Known Member
Mar 9, 2006
7,704
Virginia
Boat Info
2001 380DA
Engines
Caterpillar 3126
I replaced our factory Clarion stereo/CD Changer with a Pioneer Unit a few months ago. Since, when the stereo is on, when I press the button to talk on the VHF we get a loud, very loud, popping/crackling sound through the speakers.

I recall, when removing the original Clarion Head Unit, there was a cable installed in the back of it that went into the hull somewhere. I could never figure out what this cable was for so I simply cut it and pushed it back up into the hull. I remember recently finding where a cable, I think the same one, is grounded to the hull behind the stereo. The end was cut so I think it's the one I cut when removing the original Clarion Head Unit.

Perhaps it was some kind of ground for the VHF? If yes, how do I ground the new Pioneer Head Unit so that the VHF is happy?


Suggestions/opinions?

Thanks,
 
One end of the cable is still connected to the hull, around the gunwale on the starboard side, right behind where the stereo is installed. It resembles a coaxial cable if I recall. I'll have to take a closer look this weekend.

There was another cable too, I think this one runs to the remote controls mounted at the helm. I left that in place as I may install a Pioneer remote at a future date if we find we need it. Thus far the hand held remote that came with the Pioneer is working OK for us.
 
There is a grounding plate on the underside of the hull. It is an important item for your electronics to work properly. In fact, I am adding a second grounding plate to the Four Suns to handle even more grounding of electronics (new SSB radio). Cutting wires is bad. No one is allowed to cut wires and hide them unless they know what they do.
 
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Plate, underside of the hull, that's it.

I may not have cut the end that went into the Clarion Unit. I recall unplugging this from the back of the original head unit and wondering what it was for. At a later date, while installing the XM Tuner, I saw the plate you refer to with a cable/wire connected to it.

So now what? How do I plug this into the Pioneer head Unit as there is no matching plug on the back of the Pioneer unit. I think it was a plug/connector of some kind and not just a wire.
 
I think that wire Greg cut was the antenna to receive terrestrial broadcasts on something they called "AM/FM". Sea Ray either left a short piece of wire along the hull to act as an antenna, or connected the antenna wire to the bow rail or the hull's bang strip.

Years ago, people listened to "radio" which was a series of advertisements for products and services. Sometimes the hosts would speak inanely. Less frequently, these "radio stations" would broadcast music. Of course, Sirius Satellite Radio makes this 1930's technology obsolete and unnecessary. If the new head unit is properly grounded, including the cage, and the aforementioned antenna is connected, then the problem could be that the head unit is poorly shielded and the front end is being overwhelmed by the 25W VHF. Be thankful you don't have a SSB.

Best regards,
Frank
 
What is wrong with an SSB? It's an exercise on how fast and how many electrons you can suck out of a battery...
 
I thought that too Frank. However, the old Clarion had an antenna wire running into it so I ran this into the antenna connection on the Pioneer Unit. Once I did that I heard these strange voices coming through the "Tuner" source for the Pioneer. The antenna sits on top of our radar arch.
 
Does the Pioneer instructions show a Grounding wire somewhere?
 
Four Suns said:
What is wrong with an SSB? It's an exercise on how fast and how many electrons you can suck out of a battery...
Click to expand...


Absolutely nothing. I'd get one if I had a grown-up boat.

If a 25W VHF is overloading the front end of the head unit, the SSB's transmitter probably will smoke it!

mrsrobinson said:
I thought that too Frank. However, the old Clarion had an antenna wire running into it so I ran this into the antenna connection on the Pioneer Unit. Once I did that I heard these strange voices coming through the "Tuner" source for the Pioneer. The antenna sits on top of our radar arch.
Click to expand...

How close is the old fashioned AM/FM antenna and the VHF antenna? Perhaps you're chasing the wrong problem. Strange voices sounds like a warning sign. Maybe the radio needs an exorcism.

Best regards,
Frank C
 
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"How close is the old fashioned AM/FM antenna and the VHF antenna?"

The AM/FM antenna is on the starboard side of the radar arch, on the top of the arch. The VHF antenna is mounted on the starboard side of the radar arch, on the side of the arch. My guess, they are 2' apart. Now I am also guessing what I see on the arch is a radio antenna. It's a black rubbery looking thing, about a foot long, about the size of a pen.

Hopefully this link works and you can see both in the photo: http://www.flickr.com/photos/25124211@N03/2373121825/

" Does the Pioneer instructions show a Grounding wire somewhere?"

Yes, and I connected this to the same ground the original Clarion was connected to.
 
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There you go, I'll bet. VHF is 156-162 or so MHz. Old fashioned FM is 88-107 MHz. The receiver's front-end is... how do I put it? It's a piece of ... doo doo. It's being overloaded by the output power of the VHF. Oh well.

Best regards,
Frank
 
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it is a ground unlike cars that have a common ground...you need that ground to go to the ground plate or to a common ground buss within the boat. Try connecting the wire back to the groung lug on the back of the stereo chassis an I will bet your issue will be resolved.
 
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Grounded the stereo to the ground plate yesterday, no more popping noise when using the VHF. Thanks folks!
 
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