VHF antennas banging on bimini frame

[HeadedToTexas]

The right tension on the bimini frame stopped it from rattling in the wind, but the VHF antennas still knock against the frame in the right wind conditions as there is less than a half inch of clearance between the antennas and the frame. The knocking isn't loud on the bridge, but it is amplified in the salon where I am trying to work.

The 4 inch sections of pool float I taped on have dissolved in the elements and it's time to either replace them or upgrade to something better looking and longer lasting.

What do you guys use to dampen the banging noise of antennas on the bimini frame? At some point I might move them up onto the mast, but that isn't going to happen this season.

 

[rslifkin]

I'd be inclined to see if you can make a spacer to move the antenna mounts outboard an inch or so for extra clearance.

 

[jleonard]

I'd be inclined to see if you can make a spacer to move the antenna mounts outboard an inch or so for extra clearance.

Yes this. Mine were always outboard enough to not hit. Plus I had supports that kept them from moving so much.

 

[Gdavid]

This picture is pretty much the standard for an upper support for a antenna to keep it from banging on a cabin top or just needed support for really tall antennas. It would probably take some creativity to modify for a bimimi frame but you could probably elongate the hole so it would work on an angle. I would probably just copy the design and fabricate my own out of starboard or extruded pvc and some stainless all-thread.

 

[SIBERNUT]

Get a "split jaw slide", or a regular one. (The split can be put on when a regular wont slide, like around a corner) . Take a piece of Starboard, drill for the pin in the slide & the antenna hole, adjust width as needed. May have to warm & twist starboard to conform.

 

[HeadedToTexas]

Move the antenna! The at rest clearance is quite narrow, as in ¼ inch or so. Figure increasing that to 1" would be enough? Should be easy enough as the antenna mounts already have spacers and we have plenty of deck space to spare an inch or more. Neither the bimini frame nor the antenna move much and an extra inch would do it. Is there a normal clearance between antennas and surrounding structures?

 

[C lectric]

The main support bracket could be tilted outwards one tooth.
or
Secure a piece of vinyl tubing between the two.
or
Make a bracket with two holes, one for each offending metal tube , cut in half to split the two holes, use a screw or small machine screw in the solid part between the two holes to clamp the spacer together. Do all the hole drilling first before splitting the bracket.
For this a piece of Starboard would do well.

 

[Bacchus]

How about using 2 "window savers" that snap on Bimini frame to act as a stand off vinyl windows? Drill center and fasten them together so you can rotate them so one clips on Bimini frame the other on the antenna

https://www.etrailer.com/Accessorie...Pux3-A2H-zkpfkJzbflbCwu2S7I_clsBoCXFIQAvD_BwE

https://www.go2marine.com/Taylor-Ma...9EWosvC-2h6Rw4xLsxD_WJoURO-QyX9BoCeUIQAvD_BwE

 

[rslifkin]

I just checked my boat and the closest antenna clearance is about 2 inches. And I've never seen it flex enough to come anywhere close to hitting. My closest clearance is about 3 feet from the bottom with 8 foot antennas. Up higher you may get a bit more flex, but up to about the half-way point on an 8 footer, 1 - 1.5 inches should be enough clearance (and if it's not, it would be enough clearance to add a support bracket to prevent movement).

 

[HeadedToTexas]

The main support bracket could be tilted outwards one tooth.

Tilting the mount out a tooth would be great, but that moves the antenna out about 6 inches at head height and I'm sure it will get clipped regularly. The long term fix is definitely the thicker spacer.

 

[soin2la]

Probably only need a piece 2-3 inches long, stuck to either the antenna or bimini rail.
https://www.canadiantire.ca/en/pdp/...ductSlot=1&rrecSchemeId=product1_rr&rrec=true

 

[Flatswing]

I guess I'm too lazy. If you rarely lower the antenna, I'd zip tie the antenna to the bimini frame (what we do routinely each year as part of our Hurricane prep). I f antennas need lowering with any frequency, an elasticated Velcro strap to hold the antenna against the frame.

 

[SIBERNUT]

Why is it the noise bothers us? We don't go nuts when shrouds on sailboats bang 24/7 right along side us ?

 

[wkearney99]

Why is it the noise bothers us? We don't go nuts when shrouds on sailboats bang 24/7 right along side us ?

It sort of should bother you. Anything banging is something potentially losing material. Friction grinds away at both surfaces, often leading to early failure. Likewise loose screw/bolt connections, that leads to fasteners failing and holes going out of round (making additional repairs worse later).

Which reminds me that I need to see about tightening the bimini poles on our flybridge...

 

[GoneFarrell]

Cut a foam or sponge donut to place on the antennae or frame where it rubs the bimini frame.

Don't let it abrade the antennae surface, that can lead to problems >> new antennae.

 

[Comodave]

On our last boat I used a piece of 2” thick Starboard and made angled spacers to hold the mounts vertical on the angled side of the flybridge side. The only problem was when I was jointing them one kicked back and a finger and thumb went into the jointer a bit. Another trip to the ER…

 

[HeadedToTexas]

Yikes. No fun.

My short term fix is to lower the offending antenna to horizontal so it does not bang on the bimini frame. The interim fix is to zip tie it to the frame when underway. The long term fix is to cut spacers from thicker material to move the antennas far enough from the bimini frame to avoid banging in the wind. Good stuff. Thanks guys.

 

[Halinbrier]

Antenna Shims

I installed these antenna shims which moved the antenna away from my Bimini.

https://www.fisheriessupply.com/shakespeare-anteanna-mount-shims/414

 

[MVCalypso]

Food for thought: Antennas don't generally care for large pieces of metal right next the them, let alone touching them as it can cause odd distortions is the antenna's RF radiation pattern. If you are also having intermittent reports (from others) about your transmissions fading etc, you might want to consider moving the antennas away from the Bimini frame. OTOH if the antennas are working fine, I'd probably go with the "if it ain't broke, don't fix it" approach since relocating antennas is probably a hassle.