Let's talk antennas again

[Brian D]

Well, I want to play with my HF on my little 27 footer but don't have the funds or needs to put a large antenna on the boat. So, I was thinking today and looking in my ham catalogs and came up with a couple of ideas. Let me bounce them off you guys and see what you think.

My thought was a mobile whip antenna. I mean, the boat is like a car but does not have the mass in metal that a car has. So getting a good ground is something of an issue.

I have to options, or even more but I did not do too much research. They are a Hustler mobile HF antenna with the single band resonator or an MFJ HamTenna Whip which is all fiberglass. I thought about the Screwdriver antenna but that might be too much work.

Mounting is not an issue. I can mount the antenna on the stern rail with a mobile mounting rig. Grounding or counter poise for the antenna, now that is a different issue. The only thing I see usable is the toe rail which goes around the entire boat, save for the stern. But I think that might throw off my radiation pattern.

Any thoughts or ideas? I would willing to try anything as long as it does not get expensive. I will save the big bucks for the big boat. LOL

 

[Don S/V ILLusion]

Hi Brian
I wouldn't be too concerned with the counterpoise regardless of what (vertical) antenna you choose. Some have used the toe rail effectively, other just run a wire from the tuner ground to a thruhull. Others have gone the whole nine yards with copper foil throughout the bilge. There are so many options that it's hard to tell definitively which is the most effective.

Another option worth considering if you plan to operate while not actively sailing - a single band dipole in an inverted V configuration obviates the counterpoise concern, tuner need and RF grounding. It can be raised by any spare halyard or use a fan dipole or multiple dipoles to cover multiple bands.

Have fun experimenting.

 

[Brian D]

Don,

That brings up an interesting point. RF Grounding on a boat that is bonded electrically. How does one go about getting a good RF ground on a boat? I can see electrical grounding but I believe mostly everything metal is grounded then one would need an artificial RF ground. Do you agree? Or am I way off base on this?

 

[Don S/V ILLusion]

For a dipole or any balanced antenna, it is irrelevant. For a vertical or any antenna requiring a counterpoise, the easiest solution for RF grounding is to either use a quarter wave wire (if you are only concerned about one band) or run any length wire to a thruhull.
If your concern is coupling an RF ground to a DC ground, the option is to decouple the two with a small capacitor.

Not sure if I clearly answered your question.

 

[Brian D]

Don, you answered the question clearly, but I guess it was more rhetorical than anything else. I am sure the toe rail is grounded electrically but I will have to check. If not, then it would make a good "counterpoise" of such. Otherwise I may have to run an insulated wire around the boat. Hmmm... this is going to be fun. LOL. Thanks

 

[Brian D]

An update.

So I did some research. Three different antennas have shown potential. First is a 20 meter Zepp vertical but it is 15 feet tall. The good point is it requires no radials. The second is a double bazooka. Easy to build but it is a full size dipole so it requires me to run it to the top of the mast. Third is the Tak-Tenna. It is a dipole but in a spiral loop, like a pancake. Full size but compressed. I will build the bazooka and I purchased the Tak-Tenna. So I will do a comparison of the two on 20 meters.

 

[Don S/V ILLusion]

I'd like to read what you think after comparing both

 

[Brian D]

I will write an article and put it on my media page and will submit the article to the International Press Association. Then it will be available for other boaters as well. I know most boaters use commercial products or marine grade products but hopefully they will see there are alternatives. We'll see.

 

[Don S/V ILLusion]

Brian
Just keep in the back of your mind that you might need an antenna analyzer for the Tak if you run into problems resonating it. From what I heard, some folks hit it dead on out of the box and others have to do some tweaking for it to work well.

 

[Brian D]

I've read the same. Thanks.

 

[capbill]

I ordered a 'rope antenna' which needs a counterpoise. I ordered 2 34' sections of ladder line to string under the deck on both sides. I do have a tuner for multi-band operation.
A ham in Cruising forum. btrayfols(?) users his toe rails and successful so try the available material then upgrade if needed.