VHF Antennaes

[Jackman]

What do you think of this setup from Defender? The antenna comes with 20ft of coax so that should be enough.. Never had an extension...does the cable and connector fit down the inside of the 8ft extension? Am I missing anything?




255063
Shakespeare VHF Antenna 8' Galaxy Ext. Perf 5225-XP 4.20 Lbs. An additional handling fee of $8.50 imposed by the carrier will be included in your shipping charges for item 255063

--------------------------------------------------------------------------------

252906
Shakespeare Rachet Mount Heavy Duty Antenna Base 4187-HD 2.10 Lbs.
--------------------------------------------------------------------------------

251526
Shakespeare Galaxy Antenna Extension 5228 4.70 Lbs. An additional handling fee of $8.50 imposed by the carrier will be included in your shipping charges for item 251526

--------------------------------------------------------------------------------

252297
Shakespeare Antenna Stand Off Upper Bracket 408-R 0.55 Lbs.

 

[Artzco]

The wire feeds down into the extension and through the mount and inside the hull and into the route to the radio. Install the connector, connect to the radio and ready to go. Don't forget the conectors.

Jack, I'm no expert, but the instructions were clear and the installation easy. Good luck.

 

[Avenger]

If you're using a standoff don't bother with the ratchet mount base. Use the swivel type instead. That way when you need to lower an antenna you'll only have one thing to undo.

 

[Jackman]

A lot of these antennaes come with the connector on the end of the cable. Is there enough room to get the cable with the connector attached down the inside of the tube of the extension? Or do you have to use an antenna without the connector on the end of the cable?

 

[Jackman]

When you install an antennae how much of the antenna must be above your hardtop to maximize tx/rx? How do you know how long the radiating area of the antenna is?

 

[Boatnut]

The entire antenna radiates, best to have it all above everything, if possible. Remember every connector or adaptor you put in the line will cause a loss in signal, both tx, and rx. If the connector on the wire does not fit your vhf unit, replace it with one that will. A soldered connector will give you better results, and last longer than the solderless type.

 

[Jackman]

Wow,

So if I purchased a 19ft 8db antenna I would optimally have 19ft of antenna above my hardtop?

 

[Boatnut]

Wow,

So if I purchased a 19ft 8db antenna I would optimally have 19ft of antenna above my hardtop?

That would be correct if the antenna is 19 feet long. The extension is not part of the antenna, it is there to raise the active part of the antenna to where there are no objects in its way. From your previous description of what you are looking at, an extension, with the antenna on top sould work well for you.

 

[Avenger]

Don't confuse a two-piece antenna with an antenna and extension. Check the specs, but 8db is likely to be a two-piece. If so, the entire 19 ft of it is radiating antenna.

 

[Jackman]

Scrod...just curious about something....if the entire antennae is used to radiate signal what do folks who have the 19ft 8or9db antennas do to maximize signal tx/rx? I know they say you mount the antenna and then about 4ft above that use one of the special stay mounts. If you do that you must mount the antenna below the hardtop for sure and lose efficiency. 19ft of antenna sounds like a lot of antenna floppin around no matter what boat size its on. I can see 8ft not being a problem but what about 19ft floppin above the hardtop?

 

[Avenger]

Right, they have to be supported so we couldn't get the entire antenna above the hardtop. It would probably work better on the mast of a ship or at least a much bigger yatch. That's part of why I gave up on the uber-antenna and decided that an eight footer with an 8 ft extension would be best for me.

 

[Jackman]

Scrod,

I did find one of my issues...I have two antennas mounted within 3ft of each other. That problem will be fixed shortly...but besides the antenna top only being 2ft above the hardtop looks as though the aluminum frame of my hardtop could be causing problems as well.

Ordered the 8ft extension with the new galaxy 8ft 6db antenna. Going any higher than 6db would require, as you stated, putting an antenna that is too long on my boat practicality wise because I'd need the 8ft extension with the 18ft antennae to get it above the hardtop...too much. So 8ft stick with an 8ft extension is how I'm gonna do it.

Can a "trucker type" swr meter from a cb used to assess the installation or does vhf use something different?

Sorry for so many radio questions....not an electronics genious...I can work on motors but not electronics or electric for that matter...

 

[jim rosenthal]

If the SWR meter goes in the antenna output coax, yes. Also there is a meter that Shakespeare makes that will plug into that line for exactly that purpose. Not expensive, I think about thirty bucks or so. Mind you, I bought mine a while back.

 

[Avenger]

Radio and electronics isn't my field either. It's just that I already went through the same quandry.

Just a point of information; That 18 ft antenna still would need to be suported somewhere in the middle so if you put it on an extension to get it above the hardtop you'd still have to find some means of bracing it up high. It would be impractical. Also, after doing the math on gain and antenna height vs range I didn't believe it worth the effort, so I ended up where you are.

Good luck with the install.

 

[Artzco]

Jack, as I mentioned before, you will be satisfied with the 8+8 since it will give you good height and mine is 12 feet above the roof. I haven't had any issues with my the heavy aluminum frame supporting my hardtop. As for the upper support for the antenna, I drilled into the aluminum frame for the support since I couldn't mount to the hardtop and it allows me to reach out from the fly bridge to release and lower the antenna if needed. I've been amazed at my reception and transmission.

 

[Boatnut]

A SWR meter is a handy gadget. I say gadget because on most of these systems, you have no way to tune the antenna, or the output stage of the transmitter. Not to mention to work on a transmitter you are supposed to be licensed. I'd save my money. or maybe borrow one.

 

[Jackman]

Scrod,

Just an update...Installed the 8ft extension with the 6db galaxy 5225xp on top. The antenna base is at least two feet above the hardtop. I'd say the antenna top is at least 23ft above the water line. The SWR reading was 1.0 or slightly lower and watts were about 23, don't know how accurate the guage was.

Was out fishing and tested it with someone I knew who was at least 8miles away or so and it was crystal clear. Multiple times better than it was. Also heard someone state their location was in the Wilmington canyon, but can't believe that was true...Would be impressive if it was true though.

Thanks for the help. Seems as though things are up to par now thanks to you and the other guys on the site.

 

[Avenger]

I'm glad you got it resolved. Lots of good contributions in this thread.

Just as a point of information; I don't need to tell you that Ch 16 is full of chatterboxes asking for sea conditions, fishing reports and radio checks all day long. When we get bored we will answer that plaintive request for a radio check with "Loud and Clear. Halifax."

 

[Jackman]

Gotch Scrod. I didnt pull the radio check. I knew ahead of time a buddy was headed out. Set it up ahead of time with him. The Wilmington comment was from conversation I heard. Not radio check. Figured it was not "real".

Thanks Again!

 

[Artzco]

Glad to hear it worked out and the height is great for you. I'm always amazed at some of the distances I receive and transmit to. Enjoy.