opnions on vhf antennas

[Gettinwet]

i want to add another vhf on my boat and try and get some better range out of it.. i a an 8foot antenna mounted on top of my hardtop right now and am not getting the range i want....so educate me...what do i need.. i know the whole line of sight but is there any way to get better range and reception with out getting a 50' antenna?

[Scooper]

i want to add another vhf on my boat and try and get some better range out of it.. i a an 8foot antenna mounted on top of my hardtop right now and am not getting the range i want....so educate me...what do i need.. i know the whole line of sight but is there any way to get better range and reception with out getting a 50' antenna?

Antenna may not be the problem... could be antenna line (kinked, pinched or exposed). However, most problems are related to the antenna line connectors. Too many connectors (is the AM/FM Radio connected to the system?) or a bad connectors (due to improper install or corrosion) can create issues where power is lost at the connector or is reflected back into the radio and inhibits your radiation pattern. You need to put a watt meter on it and see what the power out vs. the reflected power. See if you can locate a local two-way radio dealer to check it out for you with a watt meter. At the same time they can make sure the radio itself is transmitting properly, when not connected to antenna. May cost a few bucks (1hr labor), but putting a nice new antenna on a poor antenna system will not solve the problem.

If everything checks out ok, you need to invest in a high gain antenna, referred to db's. The higher the db's (higher gain), the more the signal is squeezed from the top and bottom and the signal is projected out towards the horizon.

Hope this helps.

Let me know if you have any additional questions.

[Gettinwet]

i have the shortest piece of antenna wire possible from the base to the unit....but i do think i may have a voltage drop problem with my electronics up in my electronics box....i ran a single 12g positive wire and negative wire to a fuse block up in the electronic box....when i key up the mic on the vhf the gps anfd the radio blink or even shut off completely...i plan on running individual pos and neg from the breaker panel in the cabin to each device.....but do you think i will get added range by getting a better quality antenna? or even a taller antenna....current is 8 foot shakesphere

[Scooper]

Keeping the antenna line short is good, but there still could be a faulty connector or even a bad antenna. It sounds like you are putting out a Radio Frequency (RF) signal, since it seems to adversely effect the other electronics, but why? This is not good thing... You may be spraying signal all over the place rather than through the antenna and at your intended target (the horizon).

Getting a better grade antenna may help, as it will take what little signal it getsand sends it a little farther, giving you the illusion that its working fine. But it just might be masking a bigger problem. There is something wrong and needs to be addressed. You don't want your GPS blowing out every time you key up the radio... best case, you ruin your AM/FM radio and GPS. worst case, imagine calling in you position to the CG and the GPS blows out and doesn't come back...

Most people (dealers included) think installing VHF radios & Antennas is like cable TV~ D.I.Y., slap a connector on and as long as I have a picture I'm good... its not that way with radio, you can't see it so you can't tell if you have fuzzy picture or not. Every weekend I hear Capt.s doing radio checks as they clear the inlet, which is good. However, if the person responding is only 1/2 mile away, it doesn't mean you'll get the help you need if you are several miles away... all VHF radios should be tested with a calibrated watt meter by some one knows how to use it upon installation and checked annually, depending on your fishing/boating habits. At the very least when you change your batteries. just my $.02...

[Gettinwet]

my gps and my stereo...don't go out completely but they blink when i key the mic.....i think that i need more power up to my electronics box...the on set of feed wires seems to be to little for what i need... i plan on adding a radar unit and possible a second vhf...will the 2 vhf's interfer with eachother? is there anything i can do to avoid this?

[Scooper]

my gps and my stereo...don't go out completely but they blink when i key the mic.....i think that i need more power up to my electronics box...the on set of feed wires seems to be to little for what i need... i plan on adding a radar unit and possible a second vhf...will the 2 vhf's interfer with eachother? is there anything i can do to avoid this?

I see, Interpreted the display issue caused by RF getting in to these units, not from a draw on the current. Separating the power should alleviate that problem.

The only problem you will have w/ 2 radios is
1. They are keyed up at the same time on same channel.
2. they are right next one another and on the same channel or scan when 1 is keyed up, you'll get feed back

Also, to avoid possible RF issues between the antennas- try to separate the antennas as much as possible (ie don't mount 2 right next to each other), this may require you to move the original antenna (if possible). Some times frequencies can interfere with one another and "bleed through" even if the radios are locked on 2 different channels.

Go to a local radio shop, (ie- two way radios, amateur /CB radios), to get the antennas. (Not Boaters World) You'll be able to speak with someone that understands how RF works and will be extremely helpful in showing you the proper connectors and installation techniques.

Feel free to PM me if you have any problems down the road, not sure I'll be able to help, but I'll try...

[Avenger]

Scooper is much more of an expert than I am, and he seems to have you on the right track. The only thought I would add is that a higher gain antenna will have more range. So check the specs on the one you have. 9dB is commonly the highest gain offered. Hope this helps.

[Capt.Troy Crane]

Besides all of the above that was discussed,
I have used the 8ft Digital antennas for a few years with my old Icom and they are the best in my opinion. I base this on what I am told of how my radio puts out and sounds to others and the reception I get.

Good luck,
Troy

[JD5652]

Besides all of the above that was discussed,
I have used the 8ft Digital antennas for a few years with my old Icom and they are the best in my opinion. I base this on what I am told of how my radio puts out and sounds to others and the reception I get.

Good luck,
Troy

I have two VHF's on my boat..... Primary is ICOM 604 and secondary is ICOM 504. When I installed these, I installed a new 18 ft Digital antenna on the 604 and used the old 18 ft Shakespear on the 504. The 504 has issues transmitting and people think I'm on high power when I'm transmitting on low power on the 604.

I second that Digital makes a better VHF antenna, IMO.

[Radiater]

i want to add another vhf on my boat and try and get some better range out of it.. i a an 8foot antenna mounted on top of my hardtop right now and am not getting the range i want....so educate me...what do i need.. i know the whole line of sight but is there any way to get better range and reception with out getting a 50' antenna?

I like Digital brand antennas in the 8' 6 db range.

As you have already alluded to they are line of sight. The higher they are off the water the farther they "see" and transmit. I believe the effective range limit about 15 to 20' of the water is around 20 miles.

Having said that before you spend more money on one you may want to buy a Shakespeake VHF tester. It plugs in between the VHF radio and the antenna and allows you to determine if your current radio and antenna are working properly or not. It is not all that expensive and can be picked up at west marine or boater's world. You may require a short adapter wire to put between the tester and the radio for it to work which is purchased at the same place as the tester. The device will also allow you to know if your new setup is working right or not after the install.

Helped me track down a problem after an install of a new antenna on a boat. Don't cut the factory cable on a Digital brand antenna and try to splice it unless you know what you are doing.....don't ask me why.

I don't work for any of these companies..just my experience.