Mast or stern pole for Radome ?

[AHoy2]

Re: Pole...

pvb didn't say the output power was 28W, that was the total input power. If you want to feel a little less uneasy then take away the power used for the scanner rotation motor (a big chunk of the 28W), then take away the power used by the transmit and receive electronics, which doesn't leave much for the transmit device (magnetron) which isn't that efficient ..... etc.

Alternatively do the sums on transmitted power from the example above.

If there was a radhaz it would be very prominently displayed with the devices installation guide - there is plenty of legislation to cover this.

Consider the 25W radiated power from your VHF on the pole when you next make a call.

 

[Jonny_H]

Thanks - going back to the original thread ... I've got a gantry over the rear of the boat (keeps everything above head height, yet easy to get to service items):

We now have an Aero4gen mounted on the starboard side too.

Hoping to strap a solar panel up there too!

A very useful thing to have (can even hoist a dinghy onto it). Makes servicing etc very easy - plus no need to chop cables when removing the mast (although - a word of warning - we did look at having our boat moved by road and the gantry would have to have been removed so it would fit uder motorway bridges - so would have had to chop all cables - but I suppose this is an extreme one-off (in the end we sailed her - much easier!))

Jonny

 

[Captain Haddock]

Just out of interest Jonny_H where did you get your gantry from? Was it a custom job?

I think a Gantry is a great idea and a better option than a pole however, IMO it's got to suit the profile of the boat.

 

[Jonny_H]

It was on the boat when it I bought it - looks like a custom job, as it is integral to the pushpit (not welded on after) - the main front legs also go straight through the deck - so you can feed cables up them from inside the boat and keep them all tucked away neatly!

Jonny

 

[Koeketiene]

[ QUOTE ]
Oooh! What is the recommended distance between the SSB and Radome then?


[/ QUOTE ]

Have always been told - and from experience found this to be correct - to keep radar about 2m away from your SSB areal.
If the radar is closer to the backstay and it's on TX it will affect your SSB RX (you will lose some quality & range).
The main cause for concern is when both SSB and radar TX at the same time.
Modern SSB sets are quite powerfull.
I have myself noticed/heard sparks/electricty in the air - especially in humid weather.
Your radar display will be pretty much all "snow" anyway.

Another reason why I have always switched of radar when TXing on an SSB set is to spare the batteries. SSB and radar on TX draw a lot of amps, and if you have autopilot on too... it all ads up.

PS: would like to add - my experience refers to boats where the backstay was used as SSB areal - no experience of whipper antenna

 

[peterb]

[ QUOTE ]
I've got a gantry over the rear of the boat

[/ QUOTE ]

If you need a helicopter lift off the boat then they like to use the port quarter. Best to keep this area clear of obstructions.

 

[pvb]

Helicopters....

Not sure it really makes a lot of sense to compromise your ideal boat on the basis of a one-in-a-squillion chance that you might need to hitch a ride on a rescue chopper. Bit like recommending we should all drive our cars with the doors unlocked and the windows open to make it easier for the emergency services if we crash.

 

[[10753]]

Gantry gets my vote - had one made about 5 years ago and attached to the pushpit. Supports RADAR, wind genny etc. and is high enough not to interfere with the Haslar steering gear. Cross bars about 6.5 above deck at a guess.

Great for hanging on to too. Also psychologically it feels safer in the cockpit - no idea why !

Important to consider design carefully if you don't want to compromise a yachts looks. Have a good look at other yachts. Take picture of your yacht and draw the rough design on. If possible go for same gauge S/S tube as pushpit as it will look nicer. If you are considering wind generator in the future have the mounting welded at the same time - its cheaper in the long run.