Magnetic compass polarity reversal??
 

Hi,

I'm looking at relocating my satellite dish next weekend.

Just got out my trusty 30 year old SILVA compass to do a bit of surveying,
and I've noticed the red (should be north) end of the needle is pointing
south!!

By way of confirmation the needle still "dips" to the north...it's just the
wrong end of the needle that is both pointing and "dipping" to the north.

Can anybody offer a plausible explanation for this? I'm mystified!


David

Magnetic compass polarity reversal??
 

On Sun, 13 Nov 2005 12:15:19 -0000, Vortex wrote:

I'm looking at relocating my satellite dish next weekend.

Just got out my trusty 30 year old SILVA compass

What do you want a compass for? You can get close enough to the
azimuth by seeing where the sun is at about 1020GMT every morning. The
sun will be a slightly lower than the satellites used by Sky at this
time of year.

--
Cheers
Dave. pam is missing e-mail

Magnetic compass polarity reversal??
 

"Vortex" wrote in message
...
Hi,

I'm looking at relocating my satellite dish next weekend.

Just got out my trusty 30 year old SILVA compass to do a bit of surveying,
and I've noticed the red (should be north) end of the needle is pointing
south!!

By way of confirmation the needle still "dips" to the north...it's just
the wrong end of the needle that is both pointing and "dipping" to the
north.

Can anybody offer a plausible explanation for this? I'm mystified!


David


I think the compass knows best, you might have got it wrong over which way
is north.
You could also try a GPS. Go and get yourself a cheap satellite locator
instead, it will save hours of hit and miss work.

Magnetic compass polarity reversal??
 

In article ,
mark wrote:
I think the compass knows best, you might have got it wrong over which way
is north.

If you don't know the differenc ebetween north and south in your own home you
are *very* lost! ;-)

I'd always get the direction spot on using an OS map.

--
John Cartmell john@ followed by finnybank.com 0845 006 8822
Qercus magazine FAX +44 (0)8700-519-527 www.finnybank.com
Qercus - the best guide to RISC OS computing

Magnetic compass polarity reversal??
 

mark wrote:
"Vortex" wrote in message
...

Hi,

I'm looking at relocating my satellite dish next weekend.

Just got out my trusty 30 year old SILVA compass to do a bit of surveying,
and I've noticed the red (should be north) end of the needle is pointing
south!!

By way of confirmation the needle still "dips" to the north...it's just
the wrong end of the needle that is both pointing and "dipping" to the
north.

Can anybody offer a plausible explanation for this? I'm mystified!


David



I think the compass knows best, you might have got it wrong over which way
is north.
You could also try a GPS. Go and get yourself a cheap satellite locator
instead, it will save hours of hit and miss work.


Having just installed a satellite dish, unless you get a very expensive
satellite locator it only tells you that you have located a satellite,
not which one, as I found to my annoyance, ended up on Hotbird and
wanted Astra2. In the end I mounted the dish on my workbench where I
could see the TV, "tuned" it in using a Sky box to tell me which
satellite, then made a careful record of direction and angle, moved the
dish to the house, set it by my record, and heigh presto!

Magnetic compass polarity reversal??
 

Vortex was thinking very hard :
Hi,

I'm looking at relocating my satellite dish next weekend.

Just got out my trusty 30 year old SILVA compass to do a bit of surveying,
and I've noticed the red (should be north) end of the needle is pointing
south!!

By way of confirmation the needle still "dips" to the north...it's just the
wrong end of the needle that is both pointing and "dipping" to the north.

Can anybody offer a plausible explanation for this? I'm mystified!

It has been stored in a position with the needle unable to move and
close to a magnet with an opposing polarity. In other words it has been
remagnetised with the wrong polarity.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Magnetic compass polarity reversal??
 

On Sun, 13 Nov 2005 14:50:15 +0000 (GMT), John Cartmell wrote:

If you don't know the differenc ebetween north and south in your own
home you are *very* lost! ;-)

Or just moved up here from the southern hemisphere and expects the sun
to track to the north rather than the south. It's surprising how
disturbing that can be, even if you don't consciously navigate by the
sun.

--
Cheers
Dave. pam is missing e-mail

Magnetic compass polarity reversal??
 

In message , Vortex
writes
Hi,

I'm looking at relocating my satellite dish next weekend.

Just got out my trusty 30 year old SILVA compass to do a bit of surveying,
and I've noticed the red (should be north) end of the needle is pointing
south!!

By way of confirmation the needle still "dips" to the north...it's just the
wrong end of the needle that is both pointing and "dipping" to the north.

Can anybody offer a plausible explanation for this? I'm mystified!

The earth has undergone polar reversal

We're doomed, doomed I tell you


--
geoff

Magnetic compass polarity reversal??
 

"Harry Bloomfield" wrote in message
...
Vortex was thinking very hard :
Hi,

I'm looking at relocating my satellite dish next weekend.

Just got out my trusty 30 year old SILVA compass to do a bit of
surveying, and I've noticed the red (should be north) end of the needle
is pointing south!!

By way of confirmation the needle still "dips" to the north...it's just
the wrong end of the needle that is both pointing and "dipping" to the
north.

Can anybody offer a plausible explanation for this? I'm mystified!

It has been stored in a position with the needle unable to move and close
to a magnet with an opposing polarity. In other words it has been
remagnetised with the wrong polarity.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk



Sounds plausible to me.

To be clear the compass works fine, it's just 180 degrees out...so I
achieved my objective,

My dish location problem is caused by neighbouring trees which are much
taller than they were 8 years ago...

Also at the new location I need clear horizon between 28.2 East (SKY), and
13.0 East to cover Astra 19.2 and Eutelsat.

..........I have a winter of HDTV "anorakking" ahead.

David

Magnetic compass polarity reversal??
 

"Dave Liquorice" wrote in
ll.com:

Or just moved up here from the southern hemisphere and expects the sun
to track to the north rather than the south. It's surprising how
disturbing that can be, even if you don't consciously navigate by the
sun.

I checked something on astronomy software once set to South Africa, and
Orion was upside down!

It was a real shock, I don't know how they cope.

Also the Sun was below the horizon - that must be a downer

mike

Magnetic compass polarity reversal??
 

On Sun, 13 Nov 2005 12:15:19 -0000, Vortex
wrote:

Just got out my trusty 30 year old SILVA compass to do a bit of
surveying,
and I've noticed the red (should be north) end of the needle is pointing
south!!

By way of confirmation the needle still "dips" to the north...it's just
the
wrong end of the needle that is both pointing and "dipping" to the north.

Can anybody offer a plausible explanation for this? I'm mystified!

I cannot come up with why the magnetization changed, but the dip I can
explain. Compass capsules are made in North and South hemisphere types,
possibly even equatorial. If a compass needle pointed direct to the North
magnetic pole, it would point downwards at about 45 degrees in the UK. To
counteract this, the needle is actually out of balance North to South,
depending on which hemisphere it is made for. Perhaps it would be useful
to a novice scout. Instead of joining the Reciprocal Club, he might
actually get to his destination.

John Schmitt

--
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