marcot
Well-Known Member
I' m fitting a rope antenna to my icom 710. An icom at 130 tuner will be fitted too.
Do i need a balun between rope antenna and tuner?
Do i need a balun between rope antenna and tuner?
Ssb long wire antenna
- Thread starter marcot
- Start date
SimonJ
Well-Known Member
I connect my rope antenna directly to the tuner and get excellent results. My tuner is fairly close to lower end of antenna but I do not think the odd few feet makes much difference as it just becomes part of the tuned length overall.
William_H
Well-Known Member
No you do not need a balun. A balun is only used where an antenna is correctly tuned to the operating frequency and is to convert ballanced antenna to un balanced coax. ie not seen on boats.
The antenna tuner should tune the wire quite happily. The wire from the antenna to the tuner is part of the antenna so should be as short as possible especially ona steel boat.
The antenna tuenr sometimes can have problems if a frequency you want to use is close to the 1/4 wavelenth of the natenna at that frequency. The solution is to increase or decrease he wire length by about .5 metre. So that the resonant frequency of the wire is not near a used freequency.
The earthing of the tuner is perhaps most critical. Keep earth lines short and duplicated. good luck olewill
The antenna tuner should tune the wire quite happily. The wire from the antenna to the tuner is part of the antenna so should be as short as possible especially ona steel boat.
The antenna tuenr sometimes can have problems if a frequency you want to use is close to the 1/4 wavelenth of the natenna at that frequency. The solution is to increase or decrease he wire length by about .5 metre. So that the resonant frequency of the wire is not near a used freequency.
The earthing of the tuner is perhaps most critical. Keep earth lines short and duplicated. good luck olewill
wooslehunter
Well-Known Member
Here's a (hopefully) very simple explanation for the non-techies.
Antennas can either be a monopole (1 part) or a dipole (2 parts, rather like two monopoles). Typical wire type antennas used on small boats or for that matter VHF antennas are monopoles. Large ships often have wire dipoles mounted horizontally between masts. So to drive a monopole, the radio only has to drive one conductor. To drive a dipole, it has to drive two conductors.
Radios generally have a single active conductor output. i.e the middle bit of the connector. The outer bit is connected to ground. So, driving a monopole is easy. Just connect the monopole to the radio. You don't need a balun. Please don't do this though & read on. You will need an antenna tuner (ATU).
Back to baluns. These are essentially a transformer that has a single input plus ground on one side & two outputs on the other side. So, if you connect a radio to the un-balanced side, the balun splits the signal into two parts. You can then connect a dipole antenna to the balanced side & both conductors of the antenna will be driven. Strictly I guess, in transmit mode, it's being used as an unbal (unbalanced to balanced) rather than a balun (balanced to unbalanced). In receive mode, the balun is taking the two signals from the two sides of the antenna & combining them to feed the receiver.
Where does the ATU fit in? Well, antennas need to be tuned to the radio frequency. i.e the correct size. If they're not, then all kinds of horrible things happen. So, the ATU makes the antenna connector look electrically like a tuned antenna. Simples..... The AT130 is designed to feed a monopole antenna. So, connect the radio to the tuner with coax, which is an unbalanced cable. Then connect the wire antenna directly to the ATU, which has an unbalanced output. Some ATUs are designed to drive dipoles. In fact what's inside them is generally just something like the AT130 plus a balun. There's actually an ATU of sorts built into VHF antennas too.
What is most important is that the ATU ground connector is connected to a good ground. Boats on the sea are great as they're surrounded ay a conductive medium - the sea. So, connect the radio & the ATU to the radio ground system in the boat. The ATU end is most important.
Antennas can either be a monopole (1 part) or a dipole (2 parts, rather like two monopoles). Typical wire type antennas used on small boats or for that matter VHF antennas are monopoles. Large ships often have wire dipoles mounted horizontally between masts. So to drive a monopole, the radio only has to drive one conductor. To drive a dipole, it has to drive two conductors.
Radios generally have a single active conductor output. i.e the middle bit of the connector. The outer bit is connected to ground. So, driving a monopole is easy. Just connect the monopole to the radio. You don't need a balun. Please don't do this though & read on. You will need an antenna tuner (ATU).
Back to baluns. These are essentially a transformer that has a single input plus ground on one side & two outputs on the other side. So, if you connect a radio to the un-balanced side, the balun splits the signal into two parts. You can then connect a dipole antenna to the balanced side & both conductors of the antenna will be driven. Strictly I guess, in transmit mode, it's being used as an unbal (unbalanced to balanced) rather than a balun (balanced to unbalanced). In receive mode, the balun is taking the two signals from the two sides of the antenna & combining them to feed the receiver.
Where does the ATU fit in? Well, antennas need to be tuned to the radio frequency. i.e the correct size. If they're not, then all kinds of horrible things happen. So, the ATU makes the antenna connector look electrically like a tuned antenna. Simples..... The AT130 is designed to feed a monopole antenna. So, connect the radio to the tuner with coax, which is an unbalanced cable. Then connect the wire antenna directly to the ATU, which has an unbalanced output. Some ATUs are designed to drive dipoles. In fact what's inside them is generally just something like the AT130 plus a balun. There's actually an ATU of sorts built into VHF antennas too.
What is most important is that the ATU ground connector is connected to a good ground. Boats on the sea are great as they're surrounded ay a conductive medium - the sea. So, connect the radio & the ATU to the radio ground system in the boat. The ATU end is most important.
Bosun Higgs
N/A
to cut woosle's simple explanation down to basics - no. The at130 is designed to connect directly with marconi type aerials which is exactly what your long wire is.
bjl
Well-Known Member
If you want to do a little more research into antennas or SSB in general go to the YachtCom website here: http://info.yachtcom.co.uk/backstay/index.html and read the article "SSB Installation - Getting it Right!!". Bob Smith is probably one of UK's leading experts in SSB and associated antennas. He's also an extremely good instructor if you want to get your Long Range Certificate in the bag. I did the course (and passed the exam) and recall discussing in some detail different antenna solutions.
marcot
Well-Known Member
Ok. Clear. No balun. I have the ATU with kiss ssb grounding system . icom 710 is not grounded. The rope antenna will be connected to the tuner with a gto 15 cable or rg8xx. Hope it will work
Bosun Higgs
N/A
The electronics likely will work better than the system. SSB is out of date technology. I use it for ham radio but I wouldnt even contemplate trying it for serious at sea comms. Thats why the good lord invented satellites.
Neeves
Well-Known Member
If you find satellite 100% effective - let us all know. There are bits of the world where it disappears and whenever you use it, it costs.
SSB is very effective, its free (once you have the kit) and used by thousands of cruising yachtsmen (and women).
When the chips are down - someone, somewhere is monitoring SSB. Your emergency sat contact might be at the pub or simply not understand what your lat and long means, the satellites might be below the horizon - but the SSB operator will be there and respond, he will record your message, he will instantly send it on - effectively and efficiently.
In the nether regions of the world - we would not be without it.
Jonathan
KellysEye
Well-Known Member
The ATU should as close to the antenna as possible and a copper strip should be attached to the tuner and then attached to the wire that goes out of the hull to the antenna then the wire clamped on. Tape the clamp to stop any corrosion. Bear in mind the ground makes up half the aerial which is why metal boats have strongest signal, connect as many bits of metal, including the engine, inside the boat to the radio ground. Also bear in mind that if anybody grabs the aerial when transmitting their hand will be cooked from inside. If you want to test that you can light a cigarette on it. The antenna length should be around 35 feet.
Jabs
Well-Known Member
And how long are you going to make the antenna?
Unlike a back stay, you have a lot of options.
Also what material?
Thanks
Tony
Unlike a back stay, you have a lot of options.
Also what material?
Thanks
Tony
KellysEye
Well-Known Member
>And how long are you going to make the antenna? Unlike a back stay, you have a lot of options. Also what material?
Every boat I've seen with SSB uses the backstay with insulators. Remember the antenna is live when transmitting so stringing a wire up is not a good idea. As I said 35 feet length is good. For anybody with a Ketch use the backstay and the triatic stay the Z shape gives an even better signal.
Every boat I've seen with SSB uses the backstay with insulators. Remember the antenna is live when transmitting so stringing a wire up is not a good idea. As I said 35 feet length is good. For anybody with a Ketch use the backstay and the triatic stay the Z shape gives an even better signal.
