How close can the radio be to the compass

I want to move the position of my radio because I can't see it when I'm out and about on the RIB. How close can the radio be to the compass?

Attached some pictures to show what I mean.

alot depends on the particular compass ,the radio and the other equipment and accesorys on the boat ,it may be a trial and error .but i would try keep anything away from the compass,one of my biggest navigatonal mistakes and in a really bad fog [pre gps days]was that i placed the aux engine in the bow of my boat not thinking even though it was over 1.5 metres away from the compass it set it out by 10 deg ,i have used my hand held near mine and it only seems to fluctuate a few deg only whilst transmitting so even the batterys dont effect it normally ,i know of people that have left a torch on the console and thats put the compass out by a lot .

It is a problem. I could do with moving the compass away from the console which is obviously impossible. Due to an implant I have, I effect the compass. If I stand too close it changes by a couple of degrees.

I was thinking of moving the compass down to under were the radio is now but it isn't the ideal place to use.
D'oh!

You could go the whole hog and have your ships compass 'swung' by a professional. Assuming that is, your compass has the required internal magnets to do the job. You would end up with the 'best' result available, (and a deviation card for what cannot be swung out) but make sure you don't move any kit to another place after it's been done! Not sure about the effects of your own internal magnet, but always wise to carry a hand bearing compass for a cross check amongst other things

I'd leave it setup as it is. Unless your getting it swung in which case you could stick it more or less wherever you want?

Thanks for the help lads. Think I will leave it where it but angle it up towards me and make a cover.


I'd leave it setup as it is. Unless your getting it swung in which case you could stick it more or less wherever you want?

I've got into allot of trouble doing that mate :D

Bad Mr Singleton!

I really don't know what you mean old chap :cool:

On the original searider console, where do you have the compass on there. Looking at Matt H's latest creation it must be a hand held?

http://rib.net/forum/attachment.php?attachmentid=39389&d=1229790214

I had my Compass next to the Radio in my last two boats. In my situation I think there was minimal deflecsion. Trouble is there is so much in consoles that can affect a compass it's difficult to give you any sound advice.

My theory is that even if the compass is out a little 10 - 15 degrees it shouldn't make that much difference on a RIB unless things are dead calm. It's usually too difficult to use a compass in most sea states.

i have even know a compass to be accurate ,then switch on the nav lights at dusk and out goes the needle by 5 deg especially if the switch and wiring is near it ,and i would agree with Hightower keeping a boat on course within 10 deg unless its dead calm .

You've both got a good point. And considering the type of cruising I'll mainly be doing. What do ya think then lads? Move the radio, compare compass readings with a handheld and adjust as much as possible? And I'll try and stay away from the bugger :rolleyes:

JSP - I wouldn't compare to a handheld - how will you know the H/Held is any more accurate (especially if you are holding it). If you want to test the accuracy of the compass I would travel slowly along a clear transit on a calm day and compare reading to the chart. Ideally do the same in a different area (so eliminating local geological effects) and at roughly 90 degrees to the first time.

I thought one of the issues with radios and compasses was that they could swing when the speaker was in use (recieving) so even a professional will not be able to compensate for that sort of intermittent effect.

This is from the Precautions section of all the Icom radio manuals:

KEEP the transceiver at least 1 m away from the ship’s navigation compass

The speaker in the radio has a magnet, similarly, there is a magnetic field from the handset, these fields are there regardless of whether the set is on, off, receiving or transmitting.

All bad news for navigation.

Cheers Polwart and Geoffs.

I was thinking of someone else using the handheld so I could determine how much I effected it but as you've pointed out Polwart, not the best way. Will use your sugestion :thumbs:

Geoffs, thanks for the info. The radio isn't a meter away at the moment. Can't you buy shielded compasses? Or have I dreamt that?

Cheers Polwart and Geoffs.

I was thinking of someone else using the handheld so I could determine how much I effected it but as you've pointed out Polwart, not the best way. Will use your sugestion :thumbs:

Geoffs, thanks for the info. The radio isn't a meter away at the moment. Can't you buy shielded compasses? Or have I dreamt that?

Why not ditch the fixed compass and have a handheld. Lets face it its only there for when your GPS screws up anyway ;)

I have a handheld Garmin Vista GPS as well that lives in a waterprof box in the joackey. So if my plotter fails I have the handheld and if that fails then the compass is next although I have to admit I don't always head out with paper charts on board :rolleyes:

This is from the Precautions section of all the Icom radio manuals:

KEEP the transceiver at least 1 m away from the ship’s navigation compass

The speaker in the radio has a magnet, similarly, there is a magnetic field from the handset, these fields are there regardless of whether the set is on, off, receiving or transmitting.

All bad news for navigation.

Hey Geoffs, any news on these antenna prices. I'm trying to give my business to site members.

Has anyone actually tried using charts when its windy!

Cheers Polwart and Geoffs.

I was thinking of someone else using the handheld so I could determine how much I effected it but as you've pointed out Polwart, not the best way. Will use your sugestion :thumbs:

Geoffs, thanks for the info. The radio isn't a meter away at the moment. Can't you buy shielded compasses? Or have I dreamt that?

Why not ditch the fixed compass and have a handheld. Lets face it its only there for when your GPS screws up anyway ;)

I have a handheld Garmin Vista GPS as well that lives in a waterprof box in the joackey. So if my plotter fails I have the handheld and if that fails then the compass is next although I have to admit I don't always head out with paper charts on board :rolleyes:

Has anyone actually tried using charts when its windy!

It's always windy on a RIB! At what speed were you reading yours at :D

Seriously however. Scrap the fixed Compass like Chris said and use the space for the radio or something else. Buy a good quality handheld one, you can use it for taking bearings as well as a back-up. Some even have mounts that you could fix to the console and mount it there when you need it.

Is there a bit of confusion about 'hand held GPS' and 'hand bearing' compasses?!

It's pretty good practise to have paper charts on board (preferably encapsulated!) and a hand bearing compass, just incase you electronic gismos pack up. ( and maybe some parallel rules/Breton Plotter/pencil bla bla .You can always slow down/stop and make it less windy!

For what it's worth, here's a pic of my console. The compass has no more than 5 deg deviation and doesn't seem to change when the radio transmits. Since the pic was taken there's a Garmin 550 on it's bracket to the right, where the black label is. Still no discernable deviation from the compass.

In short, put the radio where you'd like it.

Oh! Yes. My compass does work. I check it by driving down transits and also by comparing it with the true course given on GPS. It's a very deadbeat compass (i.e. it doesn't swing around a lot and is slow to react) made for powerboats.

Can't you buy shielded compasses? Or have I dreamt that?

Shielded compass? How would it sense the Earth's magnetic field?

Shielded VHF, perhaps (though I haven't heard of that, either.) IMO, the speaker is the worst culprit (or more precisely, the magnet in the speaker), though if the antenna is adjacent to the compass, I could see that having an effect.

jky

how about an electronic fluxgate compass, though i suppose a lot depends on how accurate you want to be as was said earlier on in the thread , for most small fast boats unless very calm are unlikely to keep within5 to 10 deg anyhow , for every one degree out it will put you 1 mile off course over a distance of 60 miles, ,,regarding paper charts i have one cut down to the size of the likely area i operate in and keep it in the flare box for emergencys ,encapsulated and i have drawn and marked all the likely way points ie lighthouse ,bouys,church spires,with the courses marked on the line so that i can go or get back without working them out at sea ,chart looks a bit of a spiders web but it works for me .

Hi JSP,

As most have said you will find all radio makers will issue a "compass safe distance" in the hand book, normally this is about 1m.

Looking at your pix, if it were me I would def move the mic looks a tad close, just a thought.

The question to ask do you notice if your compass moves when you transmit?
This is always a good indication that its too close. Also as you will know there is a magnet in the mic and in the speaker of the radio both can and will have some level of effect on the compass.

When I am doing an install I always check for compass deviation in the indicated install location.

Oh bye the way do you drive a blue Vectra and where you in a garage in the new forest today? if not you have a double!! :0))

Hope that might help a bit.
If I can be any further help give me a bell

Cheers

Jon

Thanks for all the help everyone. All taken on board. I think I am going to move the radio and ditch the compass. Instead I'll get one of those hand held's as back up in case the GPS is talking sh!t.

Jon, wasn't me. I live a long way from there. Cheers for the help and good advice :thumbs:

. Instead I'll get one of those hand held's as back up in case the GPS is talking sh!t.


regards the handheld compass ,from what i hear over the next few months sun spot explosions effecting gps signals will be high , you may need it more than you think ,lol

regards the handheld compass ,from what i hear over the next few months sun spot explosions effecting gps signals will be high , you may need it more than you think ,lol


Sods law =)

Did anyone see a repeat of QI on TV the other night where they where saying magnetic North was going to swap with Magnetic south :]

Sods law =)

Did anyone see a repeat of QI on TV the other night where they where saying magnetic North was going to swap with Magnetic south :]

i THINK this country has been going upsidedown for a number of years, but nothing to do with the magnetic pole , lol regards mart