One of the most comprehensive tests of radar reflector performance was carried out in 1995 by West Marine www.ussailing.org. The conclusions were that the poor performance of the Firdell Blipper 210/5 and 210/7 were surprising given their popularity and reputation, and although well packaged and clever device, the models tested (i.e. 210-5 and 210-7) were not large enough to have much value aboard a vessel. Furthermore, they were also unable to obtain results consistant with those supplied by Firdell, stating that their claims were consistant with a larger reflector. The Echomax range is included in the 2003 West Marine catalogue, replacing the Firdell Blipper. Prior to publishing their test results West contacted Firdell for their comments. Firdell claimed that only Target Pattern Maps were reliable. Thereupon West further tested the unit using Target Pattern Mapping and found it made no difference to their original findings. Similar conclusions were drawn in the Practical Boat Owner test published in a series of articles see issue 391 July 1999. “Having so many reflectors close together produces a polar plot made up of several spikes ‘a good response’ separated by an equal number of deep interference troughs in which the reflection from one corner reflector cancels out the reflection from the other.” In 1993 the Trading Standards Authority forced Firdell to reprint their literature removing the claim that the Firdell Blipper met ISO 8729, RORC and ORC regulations. False claims still persist in Chandlery catalogues and on the Internet. Firdells current literature only refers to a highly volumetric structure but still makes false claims about 360 degrees performance at 2.5m2 at +/- 15 degrees of heel. As will be seen from the polar diagram below they do not achieve this performance in the vertical position. To say they only have six nulls over 10 degrees is generous. They do not have a website and have little published data on their reflectors. The target pattern map we managed to get from them was coloured in by them with crayon!

Note: the blacked in areas at the 2.5m line are zero response

see also Andrew Ridleys comments

	Echomax EM230+	BLIPPER 210-7
RCS Peak m2	24m2	April 2001 6.3m2 Nov 2001 7.96m2
Response below peak	12 peaks 20m2 @ 30 Degree intervals	Peaks - 4m2 & 5m2
Performance @ 1.25m2	100%	100%
Performance @ 2.5m2	100%	54%
Performance @ 5m2	100%	8%
Performance @ 10m2	70%	zero
+ or - 3 Degrees heel	24 sq.m @ 2.5m2- no nulls	7.96 Seven nulls exceed 10 Degrees
+ or - 9 Degrees heel	19 sq.m peak @ 2.5m2 no nulls	7.0 Seven nulls 28.5% (102.6 Degrees)
+ or - 15 Degrees heel	10 sq.m peak	7.0 Seven nulls 45% (162 Degrees)
+ or - 20 Degrees heel	5 sq.m peak	Not tested
Overall length	610 mm	595 mm
Diameter	248 mm	240 mm
Distance between centres	EM-230 560 mm EM230BR(24M2) 545 mm	545 mm
Weight	2100 gr	1879 gr
ISO 8729	CERTIFIED	FAIL
RORC	EXCEEDS	FAIL
ORC	EXCEEDS	FAIL
The above test results were obtained at QinetiQ (DERA) in April/November 2001 and May 2002.
Echomax symmetrical array Firdell Blipper 210-5 non symmetrical array. 210-7 has two additional folds.

Echomax Active-X V Sea-Me RTE

Comparison below has been made with the Sea-Me RTE which has received very good yachting press reviews and is reputed to be the best selling RTE in the UK. The Sea-Me RCS response data was obtained from the March 07 MAIB Performance investigation of marine radar reflectors following the Ouso disaster or the Sea-Me RTE manual. RCS response data source Active-X QinetiQ 13th March 09.
	Active-X Sea-Me vertical position 111.36M2 42.57M2 10 degrees of heel 78.96M2 24.87M2 20 20.80M2 4.35M2 The above figures are stated performance level (SPL)    Stand by current 15Ma 150Ma External alarm facility 8A volt free contact 90Ma 5 radars painting 23mA 350mA* 10 radar painting 32mA   Fuse Externally changeable fuse Integral fuse requires removal of control box from installation, removal of back plate to access fuse reassemble and re-installation *SeaMe Manual but does not state number of radar painting which may be one or more ALARM FACILITIES SeaMe only has a visual alarm as standard. Optional .90mA buzzer is around £40.00 Active-X has triple alarm facility as standard ie visual alarm, audible switchable alarm AND facility for 8A extension alarm.
Sept 09 PBO Active-X v SeaMe comparative sea trials - click here

Echomax Active-XS v SeaMe dual band

*Source PBO August 2010 based on Sea-Me published QinetiQ linear charts

PBO August 2010 verdict Echomax Active-XS best buy, which reported

Number of reliable paints from 10 scans
	No reflector	Sea-Me	Active-XS
S band 6.9nm	5	8	10
X band 7.5nm	3	9	10
Unfortunately no tests at heel; to see September 09 sea trials heel data please press link to PBO sea trials in Active-X section

TRILENS
The figures below illustrate the 'TriLens' 5 inch diameter reflector, for which they claim 2 to 4M2-RCS, will be hidden in moderate clutter. They also state its performance is comparable to a 12 inch corner. Presumably they mean a 12 inch octahedral RCS-2.21M2. The RCS of a single twelve inch corner is 35M2.

The only 'TriLens' reflector, to meet ISO 8729, RORC and ORC regulations is their 20 inch diameter, which weighs in excess of 15 pounds, and costs US$699. Hardly suitable for yachts!!

Rosendal's (TriLens) web page compares their Mini-TriLens with a Mobri reflector found 'invisible' by West Marine.

The performance of other reflectors, given below, was examined by QuinetiQ in the presence of independent observers.

Pains Wessex SC4	peak 7.9 sq.m
4" Mobri	6.3 sq.m
16" Octahedral	6.3 sq.m (see diagram on web site re zero 18" Octahedral 10 sq.m response of 240 deg at + or - 15 deg)
18" Octahedral
Visiball	50% 1 sq.m - 50% virtually zero - 4.7 lbs **
Blipper 210-7	6.3 sq.m - see full analysis on website
Cyclops 2	Two peaks 6 sq.m 300 degrees* 2.0m2 - 10.3 lbs
Cyclops 3	Two peaks 10.5 sq.m 280 degrees* 4.0m2 - 18.5 lbs *Cyclops literature states 360 degrees

Sailing Today Sea Trials-September 09

** Sea trials ceased at 7.3 nm due to number of radars transmitting in the area.

Visiball declined to submit a unit for test as invited.

Sailing Today Quote: 'We were unable to discern any real difference when heeled at 10 or 20 degrees'

** Latest literature we have seen accompanying Visiball states that "its computer generated surfaces ensures a consistent performance through 360 degrees and its special filling maximizes the reflection." Our tests at QinetiQ only gave a response of 1m2 for 195 degrees. The balance of 165 degrees being virtually zero response, as will be seen from the polar diagram shown below.

The following reflectors do NOT meet ISO 8729 and therefore do not satisfy SOLAS Chapter V, RORC or ORC requirements:

- Mini-Trilens, Trilens 5.25 Inch lens, Cyclops I & II, Mobri 50mm/100mm, Blipper 210-5/210-7, Pains Wessex SC4, all Octahedral based reflectors under 18 Inches Diameter, including Davis Octahedral, VisiBall.

If there is any doubt, ask the respective manufacturer for his test results.

OCTAHEDRAL REFLECTOR has been in use for over 65 years and the 18 inch forms the basis for the current ISO 8729 with a peak of 10M2. However its weakness is at 15 degrees of heel where the response falls to just .625M2 and at this angle there is no response over 140 degrees azimuth. The reflector in the catch rain position gives a good response but in many instances the reflectors are poorly positioned, particularly when installed in back stays, which renders them next to useless.

ISO 8729 For many years the 18" Octahedral reflector has been accepted as a benchmark by ISO/BSI and RORC. However, its serious failings are illustrated adjacent where, at 15 Degrees tilt, the octahedral gives no response over 140 Degrees.

MOBRI - PLASTIMO - NAVIMO stacked tube reflector Probably one of the best selling reflectors as they are relatively cheap, easy to install and come in halyard mount or with deck mount bracket fitted. Refer to www.ussailing.org where they found these units to be 'invisible a useful addition to a stealth bomber'.

The advantages of RTE's are well known, both for their compactness and excellent performance both from the measured results at Funtington and during the live trial at Fraser on 1st. March 2002.

It is interesting to note that active RTE's were initially specifically excluded in the revision to ISO 8729, as, under certain conditions, a radar display can be violently disrupted due to the unwanted response of one or more radar target enhancers causing an inter-reaction leading to self oscillation of the RTE.

This phenomenon was observed in anechoic room experiments and field experiments undertaken in Japan.

Technology has moved on since the early days of the revisions to ISO 8729 so much so that a new standard ISO 8729-2 was drafted specifically for active devices encompassing tests to ensure self oscillation would be engineered out of a product before it could meet the revised standards performance criteria. The Active X passed this section of the tests with flying colours!

The reliable response of an RTE requires a continuous ships electric supply, component reliability, good design and quality build standard.

The “Active-X” with its miserly quiescent current drain and “cutting edge of technology” design and manufacture under ISO 9002 conditions goes a long way to overcoming the problems of products of an older and less efficient design.

OUR COMMENTS
Some of the above reflectors have little value on a yacht and have been sold for the last thirty odd years to our knowledge. Both the RYA and MCA have one prime duty and that is to safe guard sailors lives at sea and we consider that they are seriously failing in their duty here. The MCA are aware which reflectors work and which ones do not but they do not want to "get political". Following an article in the RYA Magazine by the Minister of Transport we wrote to him about the present situation which was forwarded to the MCA for a 'polite reply.' Similar correspondence with the RYA President who replied that they do not recommend any particular manufacturer or product and boat owners and commercial companies must make their own decision based on the information available and their personal budget. During the development of Echomax we visited QinetiQ on many occasions and also tested competing products. We offered the RYA use of our polar diagrams so that they could advise their members accordingly. They declined our offer. The Tulia disaster off Harwich claimed four lives and the Bembridge a further three, both boats being run down by larger vessels. They are probably all now busy writing reports about the Bembridge incident, perhaps action and not words is needed here?

BACK