best aft mount for small radome?

[Latitude9.5]

I have been looking around a bit for aft mounting systems, I was originally going to mount it on the mast, but for a few reasons I have decided not to.

I have scouted a few systems, one mounts on the backstay, which i am not sure is the best route to go: http://www.radaronthelevel.com

The other is the edson pole mount system, like this one
http://shop.sailnet.com/product_info...ducts_id/23092

Anyone have any experience with any of these?

Thanks!

[swagman]

Hi Scott,
I've no direct experiences with either - we have ours mounted on a custom made 80mm stainless pole on our transom which also holds our GPS and Navtex aerials.
But I've heard some say the backstay mounted version is better as it keeps the randome level even if it looks a bit ugly - but as we've never experienced transmission / reception isssues with our fixed pole / fixed randome regardless of angle of heel - I'm not sure how true that is.
My suggestion is to seek a quote to get a custom made fixed pole instead of the Edson - it has supporting struts which do take up space and again do not look too good. If you go for a wide enough stainless tube and ensure it mounts down through the transom area so its fixed at floor and transom level - it should not need other supports to keep it rigid.
Just ensure the randome is high enough to clear the heads of anyone on deck or in cockpit - as I'm sure the emitted rays are not healthy long term!
Cheers
JOHN

[GordMay]

The Edson “Basic” 2-3/8" dia. (60mm) 7.5 Ft. high Pole Mount (#1028-23-90-1111), as advertised by Sailnet, is a light duty unitdesigned for smaller Radars, and gets most of it’s support from your stern pushpit railing. It doesn’t look like good value , to me.
Their “Deluxe & Standard” can support heavier loads, including a dinghy/outboard davit or crane.
Edson also make a “Self-Leveling” tower (#1051-35-144DL) c/w a 3-1/2" dia. (90mm) x 12 Ft. high mast c/w Hydraulic Leveler.
For more info’ goto: www.edsonintl.com

Like JOHN, I think you might be able to have a much better custom assembly fabricated, for similar costs. Even if costing a little more, it should have more appealing aesthetics, and greater utility.

[Latitude9.5]

Yea i am leaning towards the self leveling backstay mount, seems like less hassle and the self leveling is a nice concept.

[Rick]

I agree with Swagman in that with a fixed radome I have had no trouble at sea "seeing" objects within a reasonable radius of concern and, therefore, believe that the endeavor to level the radome is a non-issue.

Regardless, should you wish to install a leveling apparatus choose instead one that you manually fix at a level when on one tack or another. Self-leveling devices at sea cause undesired wear in that expensive, usually VERY difficult to replace, and practically impossible to repair radar cable.

Many people have had such cable problems with self-leveling devices. Those who don't have a problem either will or are mostly in such benign sea conditions that they don't need leveling anyway even if they like the idea.

[kimberlite]

If you plan on going offshore the questus mount is the only way to go.
when the surf is really up 20 feet + the only thing that works is a questus.
i have had the edson fixed, waltz self leveling, fixed on the mixzzen , and the questus.
in big seas all you will see is the SEA.
fair winds,
eric

[Rick]

You don't pay attention to long term cable problems do You or have you installed a manual lock to the system?

[kimberlite]

Rick,
i have about 19,500 Blue water miles on this setup in the last 4 years and i haven't had a problem. Had about 18,000 blue water miles on waltz mount-also no problems.
bear in mind that the questus is a hydraulic dampened unit so the motion is rather smoothe. I guess it will eventually fail.
if it ever does i have a spare radar cable on board.
it would be impossible to lock as it is 35 feet up on my mizzen mast.
Fair winds,
eric

[kimberlite]

Q= I've heard that the movement back and forth of the scanner can break the wires.?

A= We've only seen broken wires in improper installations. The Questus mount is designed so that there is no flexing of the wires. You must follow the installation instructions however. We have recently seen several boats with improper installations.

Rick,
it just occurred to me about their answer.
The whole cable bundle on the propper installation swings.
it does not twist or torque thus their quote.
fair winds,
eric

[Rick]

Last night I was wondering just what Questus might say regarding flexing the radar cable. I thought it would be something like, "We've sold over a million units and haven't had any complaints". Well, tongue-in-cheek, of course yet what did you expect for an answer?

I'm and engineeer, please tell me just how it is mechanically possible to fix one end of the radar cable to the display, fix the other end to the radome, rotate the radome and not flex the cable? If the whole bundle swings then the display must swing with it to avoid long term damage. Questus CANNOT possibly guarantee just how long the cable will last.

No radar manufacturor offers cable designed to be flexed repeatedly. The industrial cables which ARE designed to do so are extremely expensive as are the installation fixtures. It has been learned a long time ago that although it helps to distribute the flexture over as long of a run as possible, it still does not prevent failure. The truth about the Questus statement is that "improper installation" translates to a shorter distance over which the cable twists versus a better installation where the twist is made over a longer length.

It is not merely a matter of prudence in this instance, it is not merely a matter of spending money to periodically replace the cable, it is a matter of nasty inconvenience should that cable fail JUST when you are in a sticky situation at night or fog observing the converging vectors of other vessels, reefs, buouys or land which you must to avoid.

[ASkok]

I have had a Questus leveling unit for 8 years now and have had no problems with it. They have you put a "strain loop" in the wire were it goes into the scanner and the wire really does flex very much, I'm sure the dampening in their system helps there alot.

The system was cheaper (totally installed, my doing the work) than the stern pole option with leveling (unless I was willing to make a fiberglass pole myself, and that was to much work for me to consider).

The only thig I would do differently if I did it again would be to buy the available "extension piece" ( it raises the unit's height by 10 or 20 inches) that I wasn't smart enough to ask for when I installed mine.

Now that I have a SSB antena isolator on the backstay that is no longer an easy option for me.

[Talbot]

The self levelling systems are very rarely seen in UK, an area not exactly renown for its calm seas.

The vertical beamwidth of the radar is considerable so should not really be a problem unless you really like sailing with the rail under the water. Personally I prefer having something that is strapped down and solid as there is much less likelihood of it breaking.