Radar Target Enhancer (RTE)

My concern with RTE's is the drain on the service batteries. Small boats, like mine, tend to have "small" service batteries (85Ah or less) and I find this a problem when passage making. I have a passive radar reflector (no drain on electrical power) but on a typical 14 hour passage I usually have to run the engine two or three times to keep my service battery charged. I have a]changed my sailing lights to LEDs and currently use an iPad for electronic navigation instead of a PC but there's still a substantial power drain. I've only been caught out in fog twice in over 30 years and periodic VHF broadcasts to all ships kept me safe, professional sailors within range have been kind enough to keep an eye on my small ship. I suppose it helps if you broadcast your position (as I did). IMO you cannot sail a small boat and keep an eye on the radar picture at the same time and small boat radars are very power hungry so you really need to run the engine when Transmitting. Far too many vessels switch off their AIS systems so I'm not a fan. Good seamanship does more to keep you safe than reliance on electronics.
 
Topcat47 said:
My concern with RTE's is the drain on the service batteries. Small boats, like mine, tend to have "small" service batteries (85Ah or less) and I find this a problem when passage making. I have a passive radar reflector (no drain on electrical power) but on a typical 14 hour passage I usually have to run the engine two or three times to keep my service battery charged. I have a]changed my sailing lights to LEDs and currently use an iPad for electronic navigation instead of a PC but there's still a substantial power drain. I've only been caught out in fog twice in over 30 years and periodic VHF broadcasts to all ships kept me safe, professional sailors within range have been kind enough to keep an eye on my small ship. I suppose it helps if you broadcast your position (as I did). IMO you cannot sail a small boat and keep an eye on the radar picture at the same time and small boat radars are very power hungry so you really need to run the engine when Transmitting. Far too many vessels switch off their AIS systems so I'm not a fan. Good seamanship does more to keep you safe than reliance on electronics.
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Gary Fox said:
RTE's draw a tiny current, no comparison to actual radar, even FM.
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Less than AIS I think?

To get an RTE through type approval is going to cost a lot of cash.
It's also potentially problematic if lots of yachts suddenly sprout RTEs in busier waters.
I think that's partly why AIS was conceived.
 
TernVI said:
It could be potentially problematic is a lrge number of RTEs were smearing all over the screen.
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If there's boats smeared all over the water... Best that there are images smeared all over the radar screen.

I doubt any sensible ship operator would prefer to not see yachts which are close..

In any case the real usefulness of these is in fog and on the high seas.. the Ouzo report is fairly clear on the importance of being visible on radar.

To Topcat...

If you have issues with power easy to add a second battery and a solar panel..

There are real issues with vhf as an aid in fog see the marine notice posted above.

I often sailed in fog relying on radar plotter and concentration..

I would not do it without radar. This year my set gave up the ghost and it was nerve-wracking in fog knowing there were trawlers about...

I'll be adding AIS and an RTE next year and have bought a new to me Radar System. (Planning trip to Azores)
 
I am wondering about an RTE / AIS and so on, On a recent channel crossing I was told off by a ship I radioed for not using AIS, so I am not convinced that ships in the channel are failing to use it. That said, I do like the idea of being better seen on radar. There appears to be two generations of the echomax - x-band and dual x and s band. Does it make much difference which I go for?
 
PhillM said:
I am wondering about an RTE / AIS and so on, On a recent channel crossing I was told off by a ship I radioed for not using AIS, so I am not convinced that ships in the channel are failing to use it. That said, I do like the idea of being better seen on radar. There appears to be two generations of the echomax - x-band and dual x and s band. Does it make much difference which I go for?
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For simply being seen, an X band RTE should do as that band is used for shorter range work. However, if you aspire to ocean crossings the S band function will give *you* earlier warning that something is around. In and around the channel I've never seen the lights on my dual band Echomax quiesce, even mid Biscay there was enough about and transmitting to keep them flashing (for reference the Echomax control unit has a couple of LEDs that flash when receiving signal, one for X band and one for S. It also has an audible warning that can be connected to a much louder external noise maker)
 
My understanding of conventional pulse radar installations for larger vessels is ...
> 300 GRT, 3cm radar
> 3000 GRT, 3cm primary radar and separate secondary 3cm or 10cm radar

Also, it seems that New Technology radars are allowed on S band with no requirement to trigger traditional RACONs (Ref IMO MSC79 Resolution 192).

Even if a New Technology (e.g. FMCW variant) radar incorporated "traditional" single frequency short pulse transmission & receiption designed to inter-operate with RTEs and RACONs, the lower power of the solid state amplifier would suggest lower detection range.

It seems to me that there's a need for development of RTEs to provide interoperability with NT radar systems ... that said, I'd still like one if I was going off shore.
Edit - found this ... Link to Echomax interoperability information

Edited to note that modern RACONs are becoming available which inter-operate with NT radars.
 
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TernVI said:
It's also potentially problematic if lots of yachts suddenly sprout RTEs in busier waters.
I think that's partly why AIS was conceived.
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This raises an interesting question (and maybe what TernVI was suggesting). Would an RTE response from one yacht trigger an RTE on another yacht? If it did then in a crowded area you could set off a chain reaction. However responses fron the secondary responders would possibly be quite confusing for the originating radar as the timing and phase information would be all over the place.
 
iamtjc said:
This raises an interesting question (and maybe what TernVI was suggesting). Would an RTE response from one yacht trigger an RTE on another yacht? If it did then in a crowded area you could set off a chain reaction. However responses fron the secondary responders would possibly be quite confusing for the originating radar as the timing and phase information would be all over the place.
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No that doesn't occur.
 
[QUOTE="pandos, post: 7479677, member: 9768"

To Topcat...

If you have issues with power easy to add a second battery and a solar panel..

There are real issues with vhf as an aid in fog see the marine notice posted above.

I often sailed in fog relying on radar plotter and concentration..

I would not do it without radar. This year my set gave up the ghost and it was nerve-wracking in fog knowing there were trawlers about...

I'll be adding AIS and an RTE next year and have bought a new to me Radar System. (Planning trip to Azores)
[/QUOTE]

I don't know what you sail or what your crewing situation is. I sail alone more often than not and when I have a crew, there's usually just the two of us. I've tried to find space for a smaller engine start battery in order to double up on the 85Ah service battery but there's not enough room in my lockers to allow it. I don't like hiding my batteries away so they have to be accessible. My engine sits under the cockpit sole and I'm reluctant to relinquish any space from my small saloon lockers, so adding battery capacity isn't going to happen. I already have solar panels but they only work in daylight and while good enough to maintain battery levels, they don't produce enough to fuel the services and nav lights. I don't sail in fog if I can help it, just as I don't go to sea if a F7 or above is forecast. If I'm caught out in it, I manage the situation as best I can. I have confidence in my Cyclops passive reflector. I've seen how well it works. Not all passive devices are equal, I know ( see the QinetiQ report). My main engine is a 1GM10 and it doesn't boast much in the way of electrical output.
 
Topcat, be aware that at a 23ma load the Echomax RTE would draw 0.5ah if on constantly for 24hrs, it is a tiny electrical load. Given that you are likely to only use the device in poor viz the daily demand is likely to be much less, maybe only a couple of hours in a day out sailing. Given that your service battery is 85ah but useable capacity 42ah, the constantly on 24hr demand from the RTE represents 1% of available capacity. Were you to use it for say 2hrs in a day then it is just 0.1% of available capacity. It’s insignificant.
 
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