VHF Antenna Installation

[Blue Crabber]

Hey guys,

Well I finally have all of the pieces that I need now to get my VHF radio installed.

I purchased the Shakespeare 5225 XP antenna, Shakespeare SS racheting mount and an ICOM M422 radio. Now I just need to get it all together.

I was thinking about mounting the antenna in the port side stern corner. I thought about doing this because it will be the most out of the way spot. I don't wan't to put it starboard corner because that is the side we always dock on and I am afraid that people will grab it getting on and off of the boat. It is not a grab rail! The gas fill hose and anchor light are right there and I don't think there is any extra room for the radio.

However, doing this will require me to run the antenna cable over the motor to get up to the helm. Will this be a problem? I will be at least 6" above the motor. Will I have any interference from the motor doing this? I like this location best but don't want it to interfere with the radio reception or clarity on my end of the person I am talking to.

Thanks for all of the help!

 

[Splat]

Re: VHF Antenna Installation

Hmmmmm..... That's a good one.You may read some interference if you have a distributor cap. Less if your solid state.

More RF noise would prolly come from the spark plugs themselves. Ignition noise here can be quieted or eliminated by running a resistor spark plug. This will be a plug starting with a R such as a RC12YC. If your boat is fuel injected this problem is allready eliminated as RF messes with the ECM for the motor so everything is well shielded.

An antenna with a external ground may help eliminate any problem.

I'm sorry I don't have a definite answer here for you. Your antenna comes with RG8 cable. That's pretty good stuff with good shielding. But you won't know till you try it.

 

[Big Keepers]

Re: VHF Antenna Installation

Why not mount it closer to the helm?

 

[Blue Crabber]

Re: VHF Antenna Installation

Hmmmmm..... That's a good one.You may read some interference if you have a distributor cap. Less if your solid state.

More RF noise would prolly come from the spark plugs themselves. Ignition noise here can be quieted or eliminated by running a resistor spark plug. This will be a plug starting with a R such as a RC12YC. If your boat is fuel injected this problem is allready eliminated as RF messes with the ECM for the motor so everything is well shielded.

An antenna with a external ground may help eliminate any problem.

I'm sorry I don't have a definite answer here for you. Your antenna comes with RG8 cable. That's pretty good stuff with good shielding. But you won't know till you try it.

Bill - Thanks for the reply. I have a carbed 4.3L V6 with points but I will have to check the plugs as I am not sure if the are resistor or not.

My thoughts were similar to yours and I couldn't come up with a good answer either so I thought I would see if anyone else could. I guess I will just have to try it to find out. I can always change it if it doesn't work. Thanks for the thoughts though.

Why not mount it closer to the helm?

Well, I am not happy with any of the locations up there as it does not allow the antenna a good place to lay down for trailering. I will take another look though just in case I missed something.

Thanks for making sure that I wasn't missing something too simple though!

Anyone else have any more thoughts?

 

[Splat]

Re: VHF Antenna Installation

Do me a favor when you try it, post back and let me know how it works. This would be good knowledge to have for future reference.

Can you position the antenna temporarily to check for interference? Possible using a c clamp or something similar? Remember to check the TX with the engine running. That is transmit and get a radio check, even if it sounds good on your end, make sure your not transmitting any weird rf noise with your TX.

BIll

 

[slasmith1]

Re: VHF Antenna Installation

If it is the boat in the picture why not go throught the bildge space and back up to the helm, or around through the under seat storage in your open bow. This way you will avoid the issue with the engine.