Length of Copper Straps for Ground Plane

[roverhi]

I'm going to use copper strap radials from the tuner for my ground plane. Problem is the strap comes in 25' and 50' lengths but my boat is 35'.
From what I've read longer is better but this stuff is not cheap. Don't want to waste 20' of copper for each radial and don't want to get a poor signal if I just go with 25' for each radial. Plan is to run three radials, two under the deck on each side and one in the bilge

Would it be any advantage to run the 50' strapping to the bow and then back down the other side?? Will the copper hold together and work like a 35' length strap if I solder 25' material together to get 35'?? Will running just 25' radials significantly degrade the signal?? Oh yeah, plan on gluing the strapping to the under side of the deck with 5200.

Aloha
Peter O.
Pearson 35

[captain465]

Stop!!!!!!!!!!!!!!!!
The copper strap HAS to be below the waterline so that it can have a capacitive connection to seawater. If you have bronze thru hulls, run the copper strap to one of the bolts that hold it in place. The ground plane for a SSB is the water that your boat sits in. Gluing it under the deck will not do much good, unless you have a submarine.

[S/V Illusion]

Are you planning to use an unbalanced antenna such as a backstay wire? If so, some would argue that one strip from the tuner to a proximate thruhull will suffice. The other school abides by the more thorough approach of using as much as practicable. Proponents of each method will argue only theirs is the better approach.

In reality, every boat antenna system is unique so start with the minimal before going too far and see if the signal meets your expectations.


If you are not using an unbalanced antenna, it is a moot point - no counterpoise is necessary.

[btrayfors]

Originally Posted by captain465

Stop!!!!!!!!!!!!!!!!
The copper strap HAS to be below the waterline so that it can have a capacitive connection to seawater. If you have bronze thru hulls, run the copper strap to one of the bolts that hold it in place. The ground plane for a SSB is the water that your boat sits in. Gluing it under the deck will not do much good, unless you have a submarine.

This advice is just plain incorrect. Radials do NOT have to be below the waterline. They work perfectly well above the waterline. The goal is NOT to "capacitively couple to the seawater" in this case. See my post on RF Grounds in the Marine Environment: SSCA Discussion Board • View topic - RF GROUNDS IN THE MARINE ENVIRONMENT

There's a good case to be made -- from long experience and from antenna theory and practice -- that elevated radials work better than buried radials. Without getting into too much detail, it's only necessary to know that most any kind of elevated radial on a boat will work just fine: toerails, rubrails, lifelines, under-deck wires and copper strips, etc.

Bill

[mesquaukee]

The info I have is the length of the radials should be ¼ of the wavelength you are broadcasting on. You can have them all connected at once. They should be as straight as possible. Soldering them together is okay.
The formula is Length = 300/frequency x ¼, result is meters.
6 meg it is 40 ft,
8 meg 30.5 ft,
10 meg 24.4 ft,
12 meg 20.3 ft,
14 meg 17.4 ft,
16 meg 15 .25

[btrayfors]

Yes, these are tuned radials and can/should be used wherever possible. They are particularly good at making it very easy for the coupler to tune on a given frequency. They can be made from any type of insulated wire, as well as copper strips.

However, untuned (i.e., random length) radials work well, too. After all, the "other half" of the antenna system -- the antenna itself -- is an end-fed random length piece of wire (backstay) on most boats.

The principal beneficial effect of seawater is to enhance the bounce...the takeoff/reflection of RF waves up to the ionosphere, particularly at low angles where long-distance propagation is desired. Remember, RF waves are ATTENUATED by just a few inches of seawater (ever wonder why submarines don't use HF radio to communicate underwater?). The principal effect of pumping RF deep underwater is to heat the water :-)

Bill

[captain465]

Roverhi.
My apologies for my reply to your post regarding putting the radials for your ground plane under your decks.
I replied in the manner I did because I was informed by some members of this forum to install my ground plane as I had described.
I think I will abandon my SSB installation and go for a satillite phone instead...less conflicting information...........

[casique8]

I READ THERE IS SOMETHING NEW IN THE MARKET IS A PAINT THAT HAS METAL COMPOUND PROPERTIES AND WORKS FOR RADIOS, AND YOU DONT HAVE TO COVER A LOT DISTANCE WITH THE COPER STRIP.

[Cheechako]

....The goal is NOT to "capacitively couple to the seawater" in this case.... Does this mean the copper porous plate's mounted outside the hull are a hoax? I've always heard that the plane is better closer to the water, not "necessary" but "better"...?
roverhi: tie everything metal possible to the ground plane.... thru hulls, stancions etc.... I knew someone who used his lifeline system... had a great signal.. It would probably be just as effective to put all that strapping inside your stern lazarrette on the fiberglass hull... if it's easier...

[Not Sure]

If you're looking for something like 137mhz SSB for realtime weather satellite data reception, the length of the radials on a ground plane antenna is something like 20.5 inches.

Amateur Quarter Wave Ground Plane Antenna Calculator

[sailvayu]

Ok I have a few more questions here. I have a SEA 222 with a SEA antenna tuner. I installed the ground from the radio and tuner to a couple of thru hulls and a sintered bronze ground plate. I get what i think is good reception as i have heard boats as far away as the Verde Islands (during the day) and i am on the east coast US. So far so good. Problem is i have not been able to get anyone to respond when i try to transmit. Even boats as close as 30 miles do not seem to hear me. I am pretty sure i am putting out a single as the volts drop on my meter as i talk and the LEDs for the strobe and anchor light will glow as i talk. I take this as a good sign. I have a backstay antenna. Now I am using a piece of heavy coaxial cable to go from the tuner to backstay. I have some GTO wire on order so will be changing that next week. I just just installed a wire to one of my toe rails (aluminum) to the tuner ground today and will test that on the cruisers net in the morning. I was wondering if i should try more radials for other bands (the toe rail is 40 foot +-). If i do can they be bundled together and will they be a problem if run alongside other ships wiring AC and DC? Any thoughts on why i am not putting out a good signal that i have not thought of? I bought the radio from a trusted source and it was tested and found to be in good order. And i do get the * showing the tuner is tuned.

Thanks
Wayne Canning, AMS

[Hollen]

Sailvayu, four things:
1. Didn't know Irwin made a 40.
2. Don't forget to ground strap the radio and the tuner to the same "thru hull". Forget all the rest, just over kill. Check out Gorden Wests many articles on the subject.
3 Turn off your inverter/charger and refrig.
4. Most important of all: GET OUT OF THE MARINA!

I had the same problem many years ago. Do the above and you will be talking to Moscow, or to me in Mazatlan.

[sailvayu]

Hollen

1 It is the same as the Citation 39 just different interior, nice sailing boat. I live onboard.

2. Done first thing. Both with 2" copper strap to Dyna plate. And i have read a ton of stuff just double checking as i am surprised i have not been able to get a signal out.

3. Good idea I will try that, but I thought that was mainly for reception?

4. Damn I'm working on it lol. I can't wait to get out of here lol.

Wayne Canning, AMS
projectboatzen.com

[moonchaser]

i have ask questions, listened, studied, read, etc everything i can find in an attempt to inexpensively yet effectively fashion an ssb antenna without cutting my back-stay. so far it appears the most economical yet effective method is to simply attach a 40'+ stranded copper wire from the mast top to the antenna tuner & a ground wire to a thru hull or copper ground shoe. from what i can gather this appears to not be as complicated as some let on. eton / grundig even suggests this very method in their operators manual for the satellit 750 receiver. can anyone comment on this idea?

[mesquaukee]

Originally Posted by moonchaser

simply attach a 40'+ stranded copper wire from the mast top to the antenna tuner & a ground wire to a thru hull or copper ground shoe.

I used this method for a few years.
There was no noticeable difference when I replaced the backstay with insulators.
There was a difference when I improved the ground plane though.