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VHF Antenna on Kayak?
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Author:  DaddyOh [ Sun Feb 26, 2006 11:31 am ]
Post subject:  VHF Antenna on Kayak?

I'm going to use my OB on a large lake (Lake Kerr NC/VA). 50,000+ acres and 800 miles of shoreline.

I'd like to carry a VHF radio and do already carry a FRS Radio since the Cell Phone coverage is spotty at best. SInce the terrain is a little hilly on the VA side of the lake I'm thinking of mounting a VHF antenna on the Outback and building a base station on shore for my wife to use.

Has anyone done this and what are your experiences and hints?

Thanks

DaddyOh 8)

Author:  Klay [ Sun Feb 26, 2006 1:06 pm ]
Post subject: 

DaddyOh,

That's an interesting question. What you would need is some kind of antenna that doesn't require a ground plane. At the same time you want the RF wave you are transmitting to be vertically polarized. One type of antenna that fulfills both these requirements is called a "half-wave" vertical antenna. Many whip-type antennas require a ground plane like the roof of a car. A half-wave antenna can sit by itself not near any metal and work properly. This is what you need since the kayak is plastic. If you don't get a half wave antenna you would have to mount the whip to some kind of metal base for it to work properly.

I know all this stuff because I have an amateur radio license. (call sign aa0ww)

Just make sure the antenna you get is advertised as the "half-wave" type.
Other antennas will work to some extent anyway, but they won't get out as well (not heard from as far away) and they will also reflect some RF energy back into the radio when transmitting which is hard on the radio since it heats up then.

And remember, the higher the better. On top of the mast would be best. (wonder how that would work)

I don't have a kayak yet, but I ordered an Adventure. I've been pondering my radio choices. For VHF, I think I'll stay with a handheld. I have a Yaesu VX7R which is rated as submersible. I tested it by powering it up and swishing it around underwater for a while. It seems to hold up to immersion well.

I'm going to figure out some kind of antenna for HF that I can set up in camp and fool around with. I imagine there won't be a lot of RF pollution (electronic interference from power lines, gadgets, computers etc.) at my campsite in the BWCA, so it'll be a pleasure to make a few contacts.

I am very excited about my new Adventure with the sail, pedal, or paddle options...it just seems that with an efficient pedal drive like the Mirage system, I'll really be able to do some exploring in some remote areas that I would never reach otherwise.

Good luck!

Klay

Author:  Klay [ Sun Feb 26, 2006 1:15 pm ]
Post subject: 

DaddyOh,

I should also mention that you could use the water as a ground plane by running wires down to the water or copper foil along the hull, but this seems like a messy solution and I'm assuming you wouldn't want to go that route.

Lots of sailboats are grounded that way.

Klay

Author:  Klay [ Sun Feb 26, 2006 1:36 pm ]
Post subject:  Lake Kerr

Wow, I just looked at Lake Kerr on Google Earth...that's one big lake. VHF coverage for a kayak over the whole lake would be a tall order. I would think the only way to do it reliably would be via a repeater mounted on a nearby hill. I checked and it looks like there are a couple VHF and UHF amateur radio repeaters with good coverage of the lake. The easiest thing to do would be to get the simplest class of amateur radio license (Technician class) and just use a handheld radio to access an existing repeater.

Klay

Author:  DaddyOh [ Sun Feb 26, 2006 2:52 pm ]
Post subject:  Klay - Thanks and a few questions

Yes lake kerr is a big lake. At least initially I would not be going more than 4 miles radius. from my house it is at least 35 or 40 miles to a marina at the south end of the lake. Someday I would like to be able to trek all that way just to show that I can. (I can't now but plan to be able to). The good news is that I would have my wife trail me or proceed me in the boat or pwc. That way I won't have to paddle/peddle back.

If I persued a technical class (which I have a small about of knowledge) I supose that my wife would as well unless she would just listen to make sure I'm okay.

How do I find the list of repeaters? Also the handhelds for use with the technical class - are those so called 2 meter radios.

Thanks - I'll look into a half wave antenna as well.

DaddyOh

Author:  Klay [ Sun Feb 26, 2006 3:51 pm ]
Post subject: 

DaddyOh,

I guess your wife would have to get a license as well for the amateur radio idea to work. I don't think they want one-way transmissions to non-amateurs.

If you're talking a 4-5 mile radius, you could do that easily with marine radios, especially with a base station at the house. You'd still want to look for a half-wave antenna for the kayak...many dealers that carry these kind of radios might not know what that means...so you could make sure you ask for an antenna that does not need to be mounted on metal or grounded in any way, and you should end up with what you need.

I found the amateur repeaters by doing a google search for "Lake Kerr amateur radio repeaters," I believe.

Amateur radio operators have many different frequency ranges assigned to them...two meter radios are the same as VHF radios. 70 cm. radios mean the same as UHF radios. UHF and VHF are the most common frequencies for repeaters...there are many, many repeaters available for free use in most areas, including yours. Looks like there are one or two set up with Lake Kerr coverage in mind.

Klay

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