Whichever antenna you are going to use, backstay or whip, this page is intended to give some hints on how to get the best performance.

First thing to consider is that your SSB antenna is like a musical instrument, if you want to sound good (transmit well) then you must get it right. Although it may receive stations does not mean that it will transmit or radiate well.

The antenna starts at the top of the ATU (antenna tuner unit) and ends at the top of the antenna, if using the back stay then top insulator. Therefore the cable from the ATU to the antenna itself is part of the antenna and it is recommended that a high voltage cable is used.

The ATU electronically changes the length of the antenna to the required transmit frequencies.
This is usually done by selecting the transmit frequency on the SSB transceiver and then pressing the TUNE button.
Pressing the TUNE button on the transceiver sends a very low radio signal to the ATU.
The ATU samples the signal and electronically adjusts the antenna length to the correct resonant frequency.
This is done by using relays to switch coils in and out of circuit until the micropocessor finds the best resonant frequency.
This TUNE process takes just a few seconds and if successful the word TUNE will be displayed on the transceiver.

It is not practical to get an antenna system on a yacht to work across a wide range of wavelengths. An MF/HF SSB works on a wide range of frequencies (2MHz to 25MHz) and therefore wavelengths are between 12 metres to 150 metres.

An antenna which works on 12MHz may not be so good on 2MHz.
A good antenna on 2MHz is harder to achieve due to the long wavelength (150 metres) and may not be effective on 12MHz due the multi-wavelength of 6 wavelengths long.
When considering the antenna system, decide what frequency you are going to use the most and optimize the antenna for that frequency.

Avoid multiple wavelengths or half wavelengths as the ATU may have problems tuning to these frequencies.
If the antenna length is 15 metres long then the ATU should tune across a frequency range of 1.6 to 25 MHz with no problems.

NOTE: The antenna on an SSB systems starts at the Antenna Tuner Unit (ATU) !

Attend a YachtCom Long Range Certificate course to find out more!

The backstay can be used as an antenna, if properly insulated and a good RF connection is made to it.
Due to the length of the backstay, performance is usually better than a whip on the lower frequencies (2MHz and 4MHz).
Try and keep the antenna well clear of any metal, including bottom section of backstay.

1. Mount top insulator at least 1 metre or more from top of mast.
2. Mount bottom insulator close to deck level.
3. The antenna length, from top of ATU to the top insulator, should be no shorter then 7 metres and no longer the 15 metres.
   1. To avoid half wavelenghts on marine frequencies, the antenna lengh should be no loger the 15 metres.
   2. If antenna longer then 15 metres then ATU may have problems tuning the antenna on higher frequencies.
4. Stand the antenna cable from the antenna tuner to the backstay off uninsulated backstay or other metal by 75mm using some plastic tubing and secure with cable ties.
   1. Keep antanna as far away from other cables and metal objects as possible.

NOTE: The antenna starts at the ATU and therefore the antenna is between the ATU and TOP insulator of the backstay!

Insulated Backstay, if done properly a backstay can make a very good SSB antenna.

Connection to backstay: The weakest electric link in any backstay insulation, is the connection to the backstay. Keep the connection clean and do look from time to time for corrosion. Depending on the frequency, you may loose transmit power if you do not stand off the antenna cable from the bottom backstay section.

Standing antenna cable off the bottom of the backstay

High Frequency (HF) whip antennas usually outperform back-stay antennas due to the fact that they are mounted virtually, which is good for long range communications on higher frequencies (above 8MHz) and also helps in reducing ground wave absorption on lower frequencies.
HF whip antennas are usually 5 or 7 metres long and must be mounted correctly on the stern of a boat.
They are usually more cost effective and more reliable and easier to install then an insulated back-stay.

Whip antennas are used by many professionals, look at RNLI offshore lifeboats.

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Modem marine SSB transceiver like the Icom M801E have a second receiver monitoring for Digital Selective Calling (DSC) Distress, Urgency, Safety calls and DSC distress acknowledgments.
DSC watch receive require its own antenna and a passive whip antenna longer then 2 metres should be used.
An active antenna, which require power, should not be use because if the power fails then no Distress, Urgency, Safety or DSC distress acknowledgment are received. Also an active antenna does not comply with SOLAS regulations.

A VHF antenna is not suitable as a HF DSC watch antenna.

Click here for DSC Watch Antenna

Around the Internet you will find many ways of installing an SSB, what works on one boat may not work so well on another, the best advice is keep it simple (KISS)!

Looking at buying a compete HF SSB system with support - Click here