Antenna placement

Jas

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Need some advice and insight on where to locate an AM/FM radio antenna on my boat. I have a 1997 Gulfstream with hardtop and already have an 8’ VHF antenna. (Not planning on integrating the two.) I’m going to add a radio antenna and want to make sure it’s done right.

Thought I’d add this Shakespeare 4530 36'' AM/FM Stereo Antenna.
http://www.boatersworld.com/product/316030139.htm
Looks like it will do the job while not breaking the bank and I like the fact that it will retract. The existing VHF antenna is mounted on the hard top, on the right side, and runs through the roof into the in the radio box where it’s connected into the VHF. Pretty straightforward.

However the radio itself is mounted in the dash just to the left of the starter or single key ignition. That means the AM/FM antenna will need to be mounted on the roof run through the radio box and somehow connect into the back of the radio.

Where should the antenna go? How is the best way to feed the antenna connection to the radio? What other hardware do I need to complete the job? And what else do I need to be concerned with, or hey stupid you forgot about this! All that insight would be appreciated.

Thanks in advance,
Ted
 

catch22

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I had a Gulfstream and added a stereo set up. Imo, if you already have an 8' vhf antenna on the right side, I would mount an 8' am/fm antennna on the left side. I like the look, (symmetry) of 2 similar 8' antenna's, and that's how I did it.

Unless you have a drop tube, from the hardtop electronics box to the dash, routing the cable will be some what difficult. In my case, (no drop tube) my cables exited the electronics box on the right side and went into a hole in the large pipe leg for the hardtop, (upper right side). The cables then exit the leg in the cabin, where the stanchion leg is bolted. The problem was, it was already choked with wires and it was a very tight squeeze to add another one. If it's necassary, you could use the pipework leg on the left side. You'll have to drill a hole in the pipework about 3/8", and seal it up when your all done. Avoid drilling near any welds, (near smaller legs). You'll have to drill a hole in the cabin too, where the stanchion is bolted, (center of bolt pattern). I would go with about a 3/4" hole there. I'm not sure if the flange on the stanchion leg already has a hole in it, so be prepared to drill through the aluminum flange, as well as the boats fiberglass.
One good thing about the antenna cable, you attach the connector after you route it, and the cable is pretty small.

From there, you can run it over to the right side, (dash) in the cabin. You can either attach it to the overhead, (where the ceiling meets the bulkhead) with nylon cable straps. You can also cover it with a split loom, cable sleeve, (this is nice if your running multiple wires, or if you plan on adding more later on). Or, you can try to cut into the ceiling carpet, (monkey fur) and tuck it inside, and exit the carpet near the dash, (not easy).
 

BobP

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Alternate to Catch22's good advise, as usual, adding the drop tube may be easier, and not require an antenna lead extension, the antenna lead on my FM whip didn't make it to the bridge console, had to get an extension, along with unwanted attenuation.

If the member doesn't know what a drop tube is, go to boatraderonline and find newer models for sale and look at the photos, you will see the tube on the console up to the hardtop box.

I intend to see if I can bend one up with one inch stainless and standard deck fittings, can do it for about $30 in materiels. Free labor!
I need to do it for my Sirius antenna feed and GPS inout to Yamaha FM gauge.
If you are not a DIYer, print out the photo and go to your local fab shop for a price. The OEM Grady design looks like alum same size as hardtop frame.
 

catch22

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BobP said:
Alternate to Catch22's good advise, as usual, adding the drop tube may be easier, and not require an antenna lead extension, the antenna lead on my FM whip didn't make it to the bridge console, had to get an extension, along with unwanted attenuation.

If the member doesn't know what a drop tube is, go to boatraderonline and find newer models for sale and look at the photos, you will see the tube on the console up to the hardtop box.

I intend to see if I can bend one up with one inch stainless and standard deck fittings, can do it for about $30 in materiels. Free labor!
I need to do it for my Sirius antenna feed and GPS inout to Yamaha FM gauge.
If you are not a DIYer, print out the photo and go to your local fab shop for a price. The OEM Grady design looks like alum same size as hardtop frame.

Good idea Bob. I think if it were me, that's the way I would go. Just not real crazy about drilling into the hardtop stanchion. I've done it, lol, but....

I like the idea of using standard ss piping, (bow rail) too. Small diameter, (7/8 or 1") is big enough for a few wires and cables, yet won't restrick your visability as much as the larger ones that are normaly used, especially if you can keep it off to the right hand corner.

Another member posted about adding one. I think the only hard part would be getting the angle right on the lower electronics box, (that was discussed in his thread). I know they have angled deck fittings, maybe 15 or 30 degree? If that doesn't work, I guess you could also make a angled shim out of poly or something.
 

Jas

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Guys,

This is really very helpful info and greatly appreciated. So often, once you think you’ve got it figured out there are always some additional details to consider, so thank you again.

In reflection I do like the idea of maintaining the boats symmetry with a pair of 8’ antenna’s, I think that would look better than one 8’ and one 3’. Alternatively I always strive to keep a clean look to my boat and don’t like the idea of drilling through the hard top on the left side and having unsightly wires running from the left side of the boat to connect to the radio at the console dash. That’s gonna be a little tricky.

I’m only handy to a point and like Clint said… “a man has got to know his limitations”. No, not sure what drop tubing is and haven’t been able to find a decent pic that shows an example. Searched West Marine, Boaters World and some used boat sites. Is there an example on the GW home site or is this strictly after market?

Regards,
Ted
 

catch22

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Jas said:
Guys,

This is really very helpful info and greatly appreciated. So often, once you think you’ve got it figured out there are always some additional details to consider, so thank you again.

In reflection I do like the idea of maintaining the boats symmetry with a pair of 8’ antenna’s, I think that would look better than one 8’ and one 3’. Alternatively I always strive to keep a clean look to my boat and don’t like the idea of drilling through the hard top on the left side and having unsightly wires running from the left side of the boat to connect to the radio at the console dash. That’s gonna be a little tricky.

I’m only handy to a point and like Clint said… “a man has got to know his limitations”. No, not sure what drop tubing is and haven’t been able to find a decent pic that shows an example. Searched West Marine, Boaters World and some used boat sites. Is there an example on the GW home site or is this strictly after market?

Regards,
Ted

The "drop tube" is an aluminum pipe section that Grady uses, (on newer models) to simplify wiring runs, from the hardtop to the lower dash. It is not an after market item. You can either have a hardtop installer make one up custom, or as BobP mentioned, make one up from 1" ss railing pipe and stanchion fittings. Those items are sold at most boating stores. You would have to do the bends yourself.

This is a photo I found. It's not a very good example, but if you look closely you'll see the drop tube pipe on the right hand side of the overhead electronics box.

grady_drop_tube.jpg


like Clint said… “a man has got to know his limitations”. :lol:
 

Jas

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Got it, makes sense now. Thanks again, still working my way through it.

Ted
 

BobP

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I layed out a carboard template for a 1 inch tube design for my Sailfish. The 1 inch tube has about 7/8 inch ID. Plenty for me.

I can't get a single fitting to go into the side of the hardtop box but it really doesn't matter. I can go into the bottom all the way to the right and forward, then down far forward on the console box. Two 60 deg round base fittings and about 28 inch of 1" ss tube. I measured approx. 70 deg for the top fitting and 60 deg for the bottom one. So may have to bend the tube slightly. Will try some other angles of the bases on paper before picking up the goodies.

Each fitting is $10, and need three feet of tube, $6 per foot.

$38 and some screws and muscle.
 

BobP

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I forgot to mention, the double wide hardtop boxes on the newer models doesn't extend as far to the startboard as mine does. So coming off the bottom of it all the way to the the right, it still places the drop in a similar position (as shown in the photo) on the bridge console, at a similar slant angle. I noticed this on both a newer Gulfstream and Sailfish.

Just a tip for the DIYers out there.
 

Seahunter

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I have a 97 Seafarer with a hardtop and the electronics box. It came stock from the factory with a "drop" tube" from the electronics box to the dash so I'd be surprised if you didn’t already have one.

I routed both antenna cables and the GPS cable under the lip of the hardtop ran them as a bundle into the front of the electronics box. That way I didn’t have to drill any holes and my front curtains still fit around the bundle with ease.