Omega Owners Forum

Omega Help Area => Omega Electrical and Audio Help => Topic started by: Lampynoiseboy on 22 February 2011, 10:09:13

Title: GPS antenna
Post by: Lampynoiseboy on 22 February 2011, 10:09:13
Is a GPS antenna a GPS antenna?

Sorry, feeling cryptic this morning......

I use a Tomtom, as the NCDC2013 satnav is soooo laborious to program, but as with most the signal gets a bit lost when amongst hi-rise office blocks. Have a Tomtom external twig which works very well, but it's a pain to put on every time.

Any reason I can't use the factory fitted GPS/GSM combi & re-route the cable from the head unit to my Tomtom?

As ever, grateful for the help  ;)
Title: Re: GPS antenna
Post by: Dave DND on 22 February 2011, 11:11:29
No, most of them are quite different and require different voltages to power them up.

Never tried a Tom Tom on a Car GPS aerial, but my gut feeling is that it may not work - worst still, something could be overloaded / burnt out in the attempt.

 :-/
Title: Re: GPS antenna
Post by: mkirky on 22 February 2011, 11:22:46
Dont do it you will damage your GPS and the antenna
Title: Re: GPS antenna
Post by: Lampynoiseboy on 22 February 2011, 11:25:12
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No, most of them are quite different and require different voltages to power them up.

Never tried a Tom Tom on a Car GPS aerial, but my gut feeling is that it may not work - worst still, something could be overloaded / burnt out in the attempt.

 :-/

Sounds like time to get the volt meter out & play, I should be able to measure the voltage on both when connected?

Good shout tho, I thought they were passive.....
Title: Re: GPS antenna
Post by: Dave DND on 22 February 2011, 11:27:28
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No, most of them are quite different and require different voltages to power them up.

Never tried a Tom Tom on a Car GPS aerial, but my gut feeling is that it may not work - worst still, something could be overloaded / burnt out in the attempt.

 :-/

Sounds like time to get the volt meter out & play, I should be able to measure the voltage on both when connected?

Good shout tho, I thought they were passive.....

No, wouldn`t do that either as voltage and signal are multiplexed together, connecting a meter would "spike" the sender / receiver and probably damage them.
Title: Re: GPS antenna
Post by: Lampynoiseboy on 22 February 2011, 11:29:16
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No, most of them are quite different and require different voltages to power them up.

Never tried a Tom Tom on a Car GPS aerial, but my gut feeling is that it may not work - worst still, something could be overloaded / burnt out in the attempt.

 :-/

Sounds like time to get the volt meter out & play, I should be able to measure the voltage on both when connected?

Good shout tho, I thought they were passive.....

No, wouldn`t do that either as voltage and signal are multiplexed together, connecting a meter would "spike" the sender / receiver and probably damage them.

dagnammit, I just can't catch a break  :'(

oh well, worth a go. Cheers Dave
Title: Re: GPS antenna
Post by: mkirky on 22 February 2011, 11:31:24
Leave well alone and think of something else to play with theres plenty on an omega
Title: Re: GPS antenna
Post by: Lampynoiseboy on 22 February 2011, 11:34:54
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Leave well alone and think of something else to play with theres plenty on an omega

Most of the rest of it works!
Title: Re: GPS antenna
Post by: mkirky on 22 February 2011, 11:37:47
Never mind give it a wash
Title: Re: GPS antenna
Post by: Marks DTM Calib on 22 February 2011, 11:40:23
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No, most of them are quite different and require different voltages to power them up.

Never tried a Tom Tom on a Car GPS aerial, but my gut feeling is that it may not work - worst still, something could be overloaded / burnt out in the attempt.

 :-/

Sounds like time to get the volt meter out & play, I should be able to measure the voltage on both when connected?

Good shout tho, I thought they were passive.....

No, wouldn`t do that either as voltage and signal are multiplexed together, connecting a meter would "spike" the sender / receiver and probably damage them.

I suspect it would be fine, the key is not to 'slip' with the leads.

If the circuitry cant withstand the small capactive load of a volt meter then it sticks no chance of withstanding the static and noise around a car electrical system  :y
Title: Re: GPS antenna
Post by: Lampynoiseboy on 22 February 2011, 11:48:04
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Never mind give it a wash

Er, that's what LNG is for......


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No, most of them are quite different and require different voltages to power them up.

Never tried a Tom Tom on a Car GPS aerial, but my gut feeling is that it may not work - worst still, something could be overloaded / burnt out in the attempt.

 :-/

Sounds like time to get the volt meter out & play, I should be able to measure the voltage on both when connected?

Good shout tho, I thought they were passive.....

No, wouldn`t do that either as voltage and signal are multiplexed together, connecting a meter would "spike" the sender / receiver and probably damage them.

I suspect it would be fine, the key is not to 'slip' with the leads.

If the circuitry cant withstand the small capactive load of a volt meter then it sticks no chance of withstanding the static and noise around a car electrical system  :y

That's a fair point, Dave?

we have a debate ftw!
Title: Re: GPS antenna
Post by: aaronjb on 22 February 2011, 11:59:39
Interesting, I didn't realise they were powered and all different..

I bought a cheap (£15) generic "GPS Antenna" from Maplin, stripped the wire back to conductor & shielding and then rammed it into the back of the NCDC2013 directly (conductor down the hole, shielding onto the outside, naturally).. Lo and behold - it found satellites (which is more than it does with the stock antenna wiring where it sees precisely zip)..

Maybe I was just lucky in buying a 'compatible' one?
Title: Re: GPS antenna
Post by: Lampynoiseboy on 22 February 2011, 12:04:33
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Interesting, I didn't realise they were powered and all different..

I bought a cheap (£15) generic "GPS Antenna" from Maplin, stripped the wire back to conductor & shielding and then rammed it into the back of the NCDC2013 directly (conductor down the hole, shielding onto the outside, naturally).. Lo and behold - it found satellites (which is more than it does with the stock antenna wiring where it sees precisely zip)..

Maybe I was just lucky in buying a 'compatible' one?

Nobody can be that lucky, surely if it's generic it can't be luck?
Title: Re: GPS antenna
Post by: Dave DND on 22 February 2011, 12:42:17
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If the circuitry cant withstand the small capactive load of a volt meter then it sticks no chance of withstanding the static and noise around a car electrical system   

Whilst I agree with what you are saying, don`t forget that the (poor quality mass produced p.o.s.) hand held TomTom was designed primarily for Hikers and Bikers, not for in car !! And is not as bulletproof as in car products

 :'(
Title: Re: GPS antenna
Post by: Lampynoiseboy on 22 February 2011, 12:53:45
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If the circuitry cant withstand the small capactive load of a volt meter then it sticks no chance of withstanding the static and noise around a car electrical system   

Whilst I agree with what you are saying, don`t forget that the (poor quality mass produced p.o.s.) hand held TomTom was designed primarily for Hikers and Bikers, not for in car !! And is not as bulletproof as in car products

 :'(

Whilst I agree the early ones were, the later generation ones are designed for car- hence the waterproof version for bikes.
As for poor quality, I've never had a problem with the one I have, as oppose to the epic failure of the in-car one to get me even close to where I want to go- even after the 3mins it takes to program it. I've tried virtually every external satnav on the market, and nothing comes close to the accuracy or speed-of-use of tomtom iiho, and the 3 different makes of in-car I've used have been utter tripe in comparison.

that said, I don't use it to get to the end of my road as a lot of people do, I can find most major towns & cities in the UK without even a map (been around a bit.....), I find it's biggest use is city centres.... hence the OP
Title: Re: GPS antenna
Post by: Kevin Wood on 22 February 2011, 13:30:31
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Interesting, I didn't realise they were powered and all different..

They are all powered, generally speaking. The GPS signal levels are so low you really need gain at the antenna to make the system work. Hence most GPS receivers supply phantom DC power up the antenna cable to power an LNA on the antenna patch itself.

On all devices I've come across this has been +5v, although I would imagine most "universal" GPS antennas probably work over a reasonable range of voltages. I guess it might be lower for handheld devices which have lower supply voltages.

I can't see a problem with measuring it with a mutimeter, as long as you're careful not to short the inner conductor to the outer.

I must say my TomTom has been great. Bog standard base model that I bought years ago. It's been bounced around in the Westfield in the rain, has lunged off the windscreen numerous times yet the hardware is perfectly fine. If I do have a gripe with it it's with certain features in the software but that's true with every system I've used.

It's certainly a lot less tedious to enter a destination than an NCDC system and the only time I have problems with satellite reception is in tunnels, so I haven't found the need to worry about an external antenna.

Kevin
Title: Re: GPS antenna
Post by: Lampynoiseboy on 22 February 2011, 13:39:22
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Interesting, I didn't realise they were powered and all different..

They are all powered, generally speaking. The GPS signal levels are so low you really need gain at the antenna to make the system work. Hence most GPS receivers supply phantom DC power up the antenna cable to power an LNA on the antenna patch itself.

On all devices I've come across this has been +5v, although I would imagine most "universal" GPS antennas probably work over a reasonable range of voltages. I guess it might be lower for handheld devices which have lower supply voltages.

But as the Tom charges through a USB, which is 5v, surely that would be the same?
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I can't see a problem with measuring it with a mutimeter, as long as you're careful not to short the inner conductor to the outer.

I must say my TomTom has been great. Bog standard base model that I bought years ago. It's been bounced around in the Westfield in the rain, has lunged off the windscreen numerous times yet the hardware is perfectly fine. If I do have a gripe with it it's with certain features in the software but that's true with every system I've used.

It would be nice to turn off the voice, but still get camera alerts..... not that I speed or anything  :-X

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It's certainly a lot less tedious to enter a destination than an NCDC system and the only time I have problems with satellite reception is in tunnels, so I haven't found the need to worry about an external antenna.

Kevin

Surely you just keep going til the other end in a tunnel  ::)
Title: Re: GPS antenna
Post by: Kevin Wood on 22 February 2011, 13:45:15
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Surely you just keep going til the other end in a tunnel  ::)

Precisely, although I did come across one in Italy where there was a junction in the tunnel. ;)

Kevin
Title: Re: GPS antenna
Post by: aaronjb on 22 February 2011, 13:52:12
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Surely you just keep going til the other end in a tunnel  ::)

Precisely, although I did come across one in Italy where there was a junction in the tunnel. ;)

There's some like that in Munich, too, IIRC, and Oslo.. and there's always Westferry Circus (http://www.youtube.com/watch?v=fVBoBdX47dw) in London to really confuse your satnav  ;D
Title: Re: GPS antenna
Post by: Lampynoiseboy on 22 February 2011, 14:01:12
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Surely you just keep going til the other end in a tunnel  ::)

Precisely, although I did come across one in Italy where there was a junction in the tunnel. ;)

Kevin

beware the limehouse link too...... you wouldn't wanna end up on the isle of dogs

Don'tget excited & go looking for it, there's no dogging there!
Title: Re: GPS antenna
Post by: Dave DND on 22 February 2011, 15:17:14
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Don'tget excited & go looking for it, there's no dogging there!

That saved a trip - Bloody long way from Paignton

 ::)
Title: Re: GPS antenna
Post by: Andy B on 22 February 2011, 17:50:39
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..... Bloody long way from Paignton

 ::)

Everywhere is a long way from Paignton!  ;) ;)
Title: Re: GPS antenna
Post by: Lampynoiseboy on 22 February 2011, 18:03:48
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..... Bloody long way from Paignton

 ::)

Everywhere worth going is a long way from Paignton!  ;) ;)
;)
Title: Re: GPS antenna
Post by: Andy B on 22 February 2011, 18:06:16
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..... Bloody long way from Paignton

 ::)

Everywhere worth going is a long way from Paignton!  ;) ;)
;)

I've spent a good few week ends in Paignton in my youth.  ;) ;) ;) ;) ;)
Title: Re: GPS antenna
Post by: Lampynoiseboy on 23 February 2011, 21:12:33
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..... Bloody long way from Paignton

 ::)

Everywhere worth going is a long way from Paignton!  ;) ;)
;)

I've spent a good few week ends in Paignton in my youth.  ;) ;) ;) ;) ;)

And we're back to dogging  ;)
Title: Re: GPS antenna
Post by: Dave DND on 23 February 2011, 23:26:21
 ;D ;D ;D :P