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Question: Do I need to use the control box with my Active-XS?

Answer: A. You need not use the control box which serves 4 purposes. All electronics are in the radome.1 - junction box for wires - fuse 2 - houses extension alarm relay 3 - houses audible alarm loud speaker 4 - houses switches and LED When these are used on buoys and unmanned remote vessels the control box is not used which saves 10mA of power so stand by current on XS will be reduced to 16mA.. Use a 0.5a fused supply Blue is negative/ black - brown is positive/red + Do not use the yellow green wire tape this up. The yellow green wire senses a voltage drop when transmitting which initialises the LED If at any time you want to check that the XS is transmitting place a meter in one of the power lines - if your meter reads 190mA then you are responding to X band or 155mA to S band or 345mA to both S and X band.

Question: The Echomax Active X and XS band Radar Target Enhancer, just to clarify, just sits in standby mode until it detects a radar signal broadcast by another ship, at which point an alarm goes off and it then sends out an amplified signal representing your own ship? As a singlehander, it is the alarm feature which most interests me. how loud is it? Also, I read somewhere that these devices don't operate on the same frequency that some ships' radars use nowadays. is this the case? would the dual channel RTE improve that?

Answer: The DB rating for the buzzer out of case is 85dBA at 10cm distance which figure has been used to compare the standard and waterproof cased options which would be :-

For the standard case the sound level produced is 71dBA at 10cm distance.

For the waterproof case the sound level produced is 31dBA at 10cm distance. 
In case these ratings do not mean anything to the average person it is louder than a seat belt alarm in a car. The internal alarm will be audible below decks on most medium to large vessels in normal conditions and you will quickly switch it off in radar congested waters. The unique external alarm facility is also a standard feature and the integral extension alarm relay in the control box can be initialized as shown on our website or in the operators handbook which accompanies every product. When initialized the relay provides an 8A volt/power free circuit which you can then run anywhere in the vessel using either or both an audible alarm of your chosen volume or visible or flashing alarm.

When painted by an X band radar the green LED will illuminate and by a S band radar the yellow LED will illuminate. If several radars are painting the vessel then the LED may be on continuously. S band radar must be fitted by vessels of 3000GT or more and must have one or two X band radar as directed by the registering country or port.
S band radar is used on the oceans to penetrate rain, snow, rain, fog etc over 3NM. In this country X band is referred to as the collision avoidance radar and would be used up to 8 miles on average.

The RTE receives and returns an amplified image to interrogating radar.
The RTE will be actuated by the vessels own radar but will treat this as a single interrogating radar and continue to respond to all other radar. In this state you will not want to have the audible alarm switched on.

Active X RTE response to FMWC - Broadband radar.

Solid state- FMWC - broadband radar use a low transmit power which has steadily increased since their introduction 10 or more years ago. In the early days the Simrad 4G used 0.165 watts transmit power which was not enough to be picked up by the Active X - XS in normal sleep mode outside a range of 200-300m. Fortunately the power increases are now sufficient to activate the Echomax Active RTE and respond as shown below for the various listed makes

Broadband responses.JPG

RTE test mode

If greater detection distances are required or the need felt to respond to less powerful radar then the RTE can be placed in the test mode, however the alarm facility will be lost. The test mode is obtained by reversing the wiring to the RTE to the control box of the blue/brown cables. For the Active XS the green - yellow should be left in place. Whilst in test mode the current consumed will be increased considerably i.e.XS - 345mA instead of 26mA on standby and X - 200mA instead of stand by 15mA

RTE v Passive radar responses

To put the RTE v Passive radar responses into perspective I give below a few response of popular passive radar reflectors in the vertical position i.e. O degrees - figures quoted are Stated Performance Levels

Davis Echomaster 0.37M2 : Large Trilens 3.36M2 : Standard Trilens 2.13M2 : Echomax EM230 4.70M2 ; Echomax EM305PE 10.00M2 : Echomax Active XS - X band 118.33M2 S band 15.75M2 - The EM230 and EM305PE are used by the US Navy.

Modern radars are fitted with ARPA which does not discriminate on echo strength and to avoid clutter an object will only appear on a radar screen if it sustains a hit rate of 50% or more. The high response of the Active XS will give you the best possible chance to be seen at both greater distances and especially in poor conditions.

An RTE fitted at mast top has a distant horizon of 25+/- miles so many users prefer to fit on the side rails, transom etc which reduces the horizon to 4/6 miles where decisions can be closely monitored to avoid the possibility of a collision at sea.. 
There is a 'suggested mounting options' drawing in Active-X/XS shown below which is based on combined customer feedback and our knowledge of where not to fit.

Hope that this covers all the issues.

Question: Could you please advise how the RTE mounting height affects the response?

Answer: We do not give a mounting height in our operations manual (which is published on the website) only that the Active-X/XS must have 360 degree clear azimuth. RORC recommend a minimum mounting height of 4 meters above sea level. 
Below is a table to give you an idea of how the mounting height and height of the target affects your RTE horizon. We have chosen RTE mounting heights of 2m typical RIB, 4m typical small motor boat and 8 meter typical small yacht, 12m larger yacht and a 5m and 10m target. These figures will vary according to weather conditions and sea state.
Whilst having a high mounting height gives you the advantage of a further horizon it gives you the disadvantage of a large area of response potentially with many transmitting radar which will/may continuously trigger your RTE and the audible alarm, if switched on, may become tiresome. Even if the green/yellow and audible alarm were to be on continuously the RTE would still be responding

Question: I'm thinking of installing an XS band RTE on my new boat. I came across an online commentary which says that the RTE should be switched off while transmitting on VHF if the RTE and the VHF antennae are close to each other. This seems like something that's hard to guarantee and possibly undesirable in an emergency situation. Can you explain to me whether this is the case, please?

Answer: There is no need to switch the VHF off when the RTE is in use. 
The only reason to advise mounting on opposite sides of the mast would be to keep shadowing to an absolute minimum.
Fitting of the RTE at mast head gives you a horizon of +/-25 miles which may in busy shipping areas devalue use of the audible alarm so some boat owners choose to pole mount the RTE on their A frame, transom or side rails. The preferred location may be a trial or error until the best position is found. Ideally this would be 3 to 4 meters above sea level well above cabin or deck obstructions and as far from the mast as possible, to keep shadowing to an absolute minimum. This would reduce the horizon to 6-8 miles.
The only real no no is within the ships own radar transmitting band with of 23 degrees or flat against a mast. 
Perhaps you could give us a link to the online commentary to put the record straight.

Mounting options.JPG
Height responses.JPG

Suggested mounting options for Active radar reflectors, please be aware that the higher the unit is mounted the bigger the horizon and you will receive signals not visible to the naked eye.

Question: I have AIS fitted to my 34ft vessel what are the benefits in fitting one of your Active-RTE ? Can you also explain the difference between the X and XS units you offer for sale

Answer: AIS A (most commonly fitted on SOLAS vessels) or B (non SOLAS) and RTE are both safety items and both should be fitted wherever possible. 
AIS Class B contains a low power VHF transceiver and GPS and requires a VHF or GPS antenna. Some vessels do not use or fit AIS and many are not mandated to do so.
All ships of 300 gross tons and upwards engaged on international voyages and cargo ships of 500 gross and upwards not engaged on international voyages and passenger ships irrespective of size shall be fitted with AIS.
The AIS system will use more power than a RTE. 
Your vessels identification and position may/will show on modern vessels radar or chart plotter. On many older vessels the data will appear on a display somewhere on the bridge and needs to be interpreted.
AIS does not enlarge your vessels radar cross section on any painting radar and does not tell you that you that you are being painted. 
Although never discussed Section 23 allows competent shore authorities to prevent AIS B from transmitting their data in the case of an emergency or systems overload for a finite period of time.

X band radars work at 9.3-9.5GHz and are normally 2-25kw and fitted by pleasure boats, small ferries and smaller commercial and fishing vessels. They have a range generally 2 to 30nm (dependent on mounting height of antenna and height of target and are often for collision avoidance and navigation. Most VTS and coastal surveillance radars also use this band. 
You would expect an Active-X to be used for coastal and channel crossings typically Dover-Calais route. 
S band radar work at 2.9-3.1GHz and are required by law on all vessels over 3000 GT. The antennas are 4 meters in length and weigh upto 180kg. They transmit 10-60KW and are usually used on the high seas to penetrate heavy rain, snow and similar precipitation. Vessels of this size must also fit one or more X band radar.
Suggest you fit an XS if you are going well offshore, Atlantic, North Sea, Pacific or Channel Isles.
For exact requirements on radar/AIS/RTE see marine rules and regulations.

RTE works in conjunction with radar which is the prime long range collision avoidance tool. The RTE should enlarge most vessels RCS and make the vessel more visible on screens of interrogating radar. This is particularly important in poor visibility when the vessels normal RCS is severely attenuated and without RTE may not trigger ARPA. ARPA is fitted to most modern day radars to automatically plot radar targets and provide collision assessment information and alarms.
Active-X/XS has both visual and audible warning alarms to tell you that you are being painted and that there is a vessel with its radar in use in the area.
XS discriminates between S and X band systems. It is the vessels that carry S band being much larger that cannot stop or change course quickly. 
The extension alarm facilities on both X and XS models are vital safety alerts for the single handed sailor or night watchman.

Question: I have an AIS - Receive only. How will fitting a RTE help me?

Answer: These devices are capable of receiving and displaying data from Class A and Class B systems, If, of course, the other vessel is AIS fitted and their AIS is switched on! Remember, this is not always the case! You will be able to see AIS active vessels. BUT THEY WILL NOT BE ABLE TO SEE YOU

Question: Can you please tell me how I can register my new Active-XS on to my Ships License?

Answer: To add your Active-X/XS to your Ships VHF License on line you will need to be registered to use the online service and login in. If not you will need to register to use it. Go to 
When you have logged in and see the page with your licence(s) listed, click on amend licence and work your way through until you come to the add equipment page. Expand the relevant section and add your new equipment, save the changes and then print your new licence

Question:Part of email from one customer............ the unit seems to work fine but some freighters did not see a 'big' echo, only a 'normal' one.

Answer: Modern radar response may not change brilliance when the echo strengthens. A "paint" or response on a radar screen indicates that the target is above the radar's detection level. Radars fitted with ARPA (Automatic Radar Plotting Aid) do not necessarily discriminate between large and small echoes and will only automatically acquire and actively plot an object with a return or hit of 50% or more. The increased RCS response of an Active-X will be a benefit at a distance, when the vessel is bows or stern on or in mist, rain or precipitation when the vessel may not otherwise not be seen. 
From what you say the unit is performing as expected as you are being seen!

You will not benefit from any RTE if the vessels Radar Cross Section (RCS) is greater the RTE. The advantages of fitting an Active-X were illustrated during the PBO Active-X v Sea Me sea trials which are published on . Using the same test vessel fitted with both SeaMe and Active-X the test radar lost the vessel with the SeaMe switched on at 5.5nm. With the Active-X switched on the same radar continued to pick up the same vessel at 6.7nm when sea trials were ceased due to too much radar traffic in the solent area. Likewise Active-X continued to give response at greater degrees of heel. No doubt the vessel would continued to be picked up at a greater distance had the Active-X trials continued.

Control box check - 

Check fuse which is at located at base and gently turn holder anti clockwise and remove and check.


If red LED illuminates check that power is available at RTE connections with a Ma meter of bulb.


Check the RTE connections/green plugs to the control box are good. Previous problems have been caused by poor wire connections in green plugs. To tighten they need to be turned anti clock wise.


RTE check


The RTE requires a 12V DC power so it may be easier to isolate from control box using a 12v battery rather than vessel power. Tape up green/yellow this is not an earth. This senses the voltage drop when responding to S band radar causing the yellow LED to illuminate 


Standby/sleep mode

Connect RTE brown + to red supply via a Ma meter

Connect RTE blue - to black supply

You should be a reading of 15/17mA


Test Mode

 Reverse power - i.e.

Connect RTE brown to black supply via a Ma meter

Connect RTE blue to red supply 

You should get a reading of 345/375mA +/-

If you get the above responses then the RTE is working to specification and indicates poor or damaged wiring or other fault. 

Question: We are installing your Active XS on A frame of our fleet of 7m RIBS and would like to know the safe distance for human exposure to their electromagnetic Microvaves.  What is the recommended safe distance for Human exposure to electromagnetic fields 

A. The Echomax Active X and XS meets US reg 47CFR Ch1.1310-1 and EU Directive 1999/519/EC-2 Annex 111 and the safes “worst case distances” are –

 Active X -  Radius 11.5cm > 4.5inches -  Active XS Radius 7cms > 3 inches

 Note – These figures are based on the continuous peak output power and in practice the RTE will only be illuminated for a small percentage of the time, so the safe distance will be significantly reduced.

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