# Can you recommend a compass for the cab?



## Seeker (Dec 26, 2005)

Hello all

We have a normal hand-held compass but it's useless inside the cab owing to there being so much metal around. When the SatNav is on then that gives an indication of compass points but when you're out of range...

So what I'd really like is to mount a compass in the cab permanently that is not affected by the metal around and doesn't depend on satellites. Has anyone got one they can recommend, please?

On re-reading this I'm wondering if it's self-contradictory because if it's unaffected by the metal in the cab won't it be unaffected by the Earth's poles too???

Thanks

Harry


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## Seeker (Dec 26, 2005)

Have found one in a web search that allows it to be calibrated for the metal in the cab. But might it be affected by the electrics once the engine is on?


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## andyman (Aug 31, 2006)

I had mine from Roadpro, it also shows inside and outside temperature. From memory It was about £25. Worked well in a coachbuilt.


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## Seeker (Dec 26, 2005)

Thanks Andy

They have one on sale now for £20, battery powered. It shows compass bearing, time and inside temperature but I can't see any reference to calibrating to cancel out the effects of the cab metal. Does/did yours have that facility?

https://www.roadpro.co.uk/retail/pr...XT:+Digital+Compass/Clock/Thermometer&id=1219

Cheers

Harry


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## rayrecrok (Nov 21, 2008)

Hi.

I am afraid there is no such thing as a compass that is unaffected by any metal in the van, electrics, speaker magnets and the such.

Does you GPS have a compass pointer on it, most do and these are unaffected by any deviation from outside sources, what type of sat nav have you?.

If you want a rough guide to direction, then I suppose any compass will do the job even one out of a Christmas cracker..

Ray


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## Seeker (Dec 26, 2005)

Thanks Ray.

I assume that those that are sold specially for cars have instructions that you fit it where you want it then line up the vehicle to point North (using some other certain means) and then twiddle with some internal adjuster to get the gadget also to indicate North, cancelling out the local magnetic fields.

This presumably would mean that thenceforth it would respond to magnetic North over and above the local effects of metal in the cab. Indeed, logic advises me that it would then give a truer indication of map North than a raw indication of magnetic North from a compass outside of the vehicle.

I assume.

Harry


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## rayrecrok (Nov 21, 2008)

Seeker said:


> Thanks Ray.
> 
> I assume that those that are sold specially for cars have instructions that you fit it where you want it then line up the vehicle to point North (using some other certain means) and then twiddle with some internal adjuster to get the gadget also to indicate North, cancelling out the local magnetic fields.
> 
> ...


Hi.

I suppose logic says fit it to make it point in the fore and aft line of your vehicle ignoring North as its the compass needle pointing to North that matters and the way your vehicle is orientated is irrelevant as its the compass direction that is the only thing of concern, and its from this you will be able to orientate you map.

In the most simplistic way of looking at it, your compass whether it's in your vehicle or out of it is the thing you are bothered about exactly the same as your hand bearing compass.

Or if you need accuracy get an orienteering compass







which has lines printed on to line up with an Ordnance Survey type map..


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## nicholsong (May 26, 2009)

Harry (OP)

Out of interest, what do you want it for? After all it is not possible to follow a compass course for long in a MH unlike in an aircraft or at sea.

However, standby compasses in light aircraft, which are not calibrated, are globe-shaped ones mounted above the windscreen, where there is least ferrous material and induced magnet fields from electrical circuits. If you can find a scrap one it might suit, but a new one would probably be exhorbitant (CAA-approved and all that)

Geoff


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## DTPCHEMICALS (Jul 24, 2006)

Just follow the sun. Basic boy scouts.

Dave p


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## rayrecrok (Nov 21, 2008)

DTPCHEMICALS said:


> Just follow the sun. Basic boy scouts.
> 
> Dave p


If it's coming up on the horizon it's in the East, if it's 12 noon it's due South of you, put your back to it at noon and you are facing North, if it's going down over the horizon it is West of you.

Sorted.. :wink:


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## steco1958 (Mar 5, 2009)

Seeker,

Have a look at www.roadpro.co.uk

Lots of stuff


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## philbre (Nov 13, 2008)

*i wonder*

if you have an i phone

theres a compass available as a free app


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## cabby (May 14, 2005)

Ray, you must have been a boy scout. :roll: :roll: 

cabby


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