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NigelWilliams Occasional Visitor
Joined: Dec 19, 2005 Posts: 6
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Posted: Wed Nov 15, 2006 4:34 pm Post subject: Efficiency of Mio c710 TMC FM Antenna |
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Hi There
I acquired a Mio c710 a few months ago and have been pleased with it. Including the TMC capabilities.
However I changed my car last week and the supplied TMC FM antenna seems unable to locate the radio stations through the new windscreen.
I have been advised that a longer antenna running across the top of the windscreen will resolve this problem.
I am having problem sourcing a replacement with a 3.5mm jack connector as required by the Mio.
All the FM aerials I have found are supplied with a coax type connector.
Does anyone know of a supp;ier of longer FM antenna or does someone know how to 'mofify' a coax-style FM antenna.
Your advise and help will be appreciated. |
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Sallyann Lifetime Member
Joined: Jun 23, 2006 Posts: 768
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Posted: Wed Nov 15, 2006 11:16 pm Post subject: Re: Efficiency of Mio c710 TMC FM Antenna |
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NigelWilliams wrote: |
However I changed my car last week and the supplied TMC FM antenna seems unable to locate the radio stations through the new windscreen.
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If the signal is not getting through the windscreen due to a metallic coating, replacing the antenna with another type in the same place will not really help. You would be better off tapping into the inner conductor of the feeder from the car radio aerial. You'll find a recent thread about this.
The C710 has only a single aerial connection on the 3.5mm plug - it is designed to have a quarter-wave wire directly connected to it, not a coaxial cable.
Sal |
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ernest_mio Regular Visitor
Joined: Aug 24, 2006 Posts: 98
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Posted: Wed Nov 15, 2006 11:37 pm Post subject: Re: Efficiency of Mio c710 TMC FM Antenna |
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Sallyann wrote: | NigelWilliams wrote: |
However I changed my car last week and the supplied TMC FM antenna seems unable to locate the radio stations through the new windscreen.
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If the signal is not getting through the windscreen due to a metallic coating, replacing the antenna with another type in the same place will not really help. You would be better off tapping into the inner conductor of the feeder from the car radio aerial. You'll find a recent thread about this.
The C710 has only a single aerial connection on the 3.5mm plug - it is designed to have a quarter-wave wire directly connected to it, not a coaxial cable.
Sal |
Sal - if your free this weekend can you come round and wire mine up for me please as I have the same problem since changing cars - |
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Sallyann Lifetime Member
Joined: Jun 23, 2006 Posts: 768
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Posted: Thu Nov 16, 2006 12:52 am Post subject: |
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Sorry, I don't much fancy pulling radios out to get at the cables. That's why I use a thin wire aerial. Fortunately our cars don't have those metallic coated windscreens.
Sal |
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NigelWilliams Occasional Visitor
Joined: Dec 19, 2005 Posts: 6
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Posted: Tue Nov 28, 2006 5:05 pm Post subject: |
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Sallyann wrote: | Sorry, I don't much fancy pulling radios out to get at the cables. That's why I use a thin wire aerial. Fortunately our cars don't have those metallic coated windscreens.
Sal |
I have been experimenting with the position of the supplied antenna and have found that it works fine when attached vertically up to the top of the windscreen.
So I think the FM radiowaves are getting through the windscreen.
So does anyone know where I can get a longer 3.5mm FM antenna from to hide it around the outside of the windscreen seal? |
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klystron_generator Regular Visitor
Joined: Nov 25, 2006 Posts: 114
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Posted: Tue Nov 28, 2006 5:27 pm Post subject: |
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Have you tried Maplin or Radio Spares (RS) and or their online equivalent |
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klystron_generator Regular Visitor
Joined: Nov 25, 2006 Posts: 114
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mikealder Pocket GPS Moderator
Joined: Jan 14, 2005 Posts: 19638 Location: Blackpool , Lancs
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Posted: Tue Nov 28, 2006 6:48 pm Post subject: |
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NigelWilliams wrote: | So does anyone know where I can get a longer 3.5mm FM antenna from to hide it around the outside of the windscreen seal? | Have a read through THIS thread, a number of components and suppliers are listed for an aerial and/ or addaptors to/ from BNC connector types including 2,5MM and 3,5MM jack plugs, once you have the addaptor you should be able to find more aerials that will connect to your device - Mike |
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Sallyann Lifetime Member
Joined: Jun 23, 2006 Posts: 768
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Posted: Tue Nov 28, 2006 7:03 pm Post subject: |
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NigelWilliams wrote: |
So does anyone know where I can get a longer 3.5mm FM antenna from to hide it around the outside of the windscreen seal? |
A longer wire won't necessarily give you more signal, since the supplied one is cut to the correct resonant length for the FM band. But if you decide to make up your own aerial you need a 4-pole 3.5mm plug, Maplin part no. QT65V. Connect the wire to the outer ring furthest from the tip.
Sal |
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NigelWilliams Occasional Visitor
Joined: Dec 19, 2005 Posts: 6
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Posted: Wed Nov 29, 2006 7:17 am Post subject: |
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Sallyann wrote: | NigelWilliams wrote: |
So does anyone know where I can get a longer 3.5mm FM antenna from to hide it around the outside of the windscreen seal? |
A longer wire won't necessarily give you more signal, since the supplied one is cut to the correct resonant length for the FM band. But if you decide to make up your own aerial you need a 4-pole 3.5mm plug, Maplin part no. QT65V. Connect the wire to the outer ring furthest from the tip.
Sal |
Thanks again.
I wasnt looking for more signal Sal, I was looking to locate a windscreen FM aerial around the windscreen in a similar way to Mobile Phone T-Bar aerials. So the aerial can remain in position and hidden away.
Seems like I cant find the parts in the sites...
So does anyone know of a In Car Windscreen FM aerial and the necessary connector for my Mio C710?
Thanks in advance.... |
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dpmguy Occasional Visitor
Joined: Nov 06, 2006 Posts: 32 Location: Mostly Hampshire
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Posted: Wed Nov 29, 2006 10:53 am Post subject: |
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Sallyann wrote: | NigelWilliams wrote: |
So does anyone know where I can get a longer 3.5mm FM antenna from to hide it around the outside of the windscreen seal? |
A longer wire won't necessarily give you more signal, since the supplied one is cut to the correct resonant length for the FM band. But if you decide to make up your own aerial you need a 4-pole 3.5mm plug, Maplin part no. QT65V. Connect the wire to the outer ring furthest from the tip.
Sal |
Sal, if you have a shielded coax is the shield attached to anything? _________________ Regards,
DPM
-------------------------------
Mio C510E - 1st purchase very impressed.
Now running V3.2 |
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Sallyann Lifetime Member
Joined: Jun 23, 2006 Posts: 768
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Posted: Wed Nov 29, 2006 12:51 pm Post subject: |
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dpmguy wrote: |
Sal, if you have a shielded coax is the shield attached to anything? |
No, that's the problem. It is an unbalanced input intended for a quarter-wave antenna to be directly connected. You will notice that there are no 'ground' connections available anywhere on the unit where you could connect a coax screen. This is standard practice, to avoid any earth loops that could cause a safety hazard under power supply failure conditions.
I can only suggest two ways to get a good signal: run a thin wire vertically up to the rear-view mirror (that's what we do); or connect via an isolating capacitor to the car radio's aerial feed (that's probably the best solution if you don't mind pulling the dashboard apart and opening up the cable)
Sal |
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dpmguy Occasional Visitor
Joined: Nov 06, 2006 Posts: 32 Location: Mostly Hampshire
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Posted: Wed Nov 29, 2006 3:29 pm Post subject: Post Subject |
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Thanks Sal,
A comprehensive answer as usual. Was only thinking of meddling with my setup.
Not leaving things alone when they work has got me in trouble to many times before; especially with my PC.
I will leave the supplied wire antenna running from the middle of the dashboard along the bottom of the screen and up the edge on the passenger side; this seems to get a good signal compared to having it flat along the bottom edge. _________________ Regards,
DPM
-------------------------------
Mio C510E - 1st purchase very impressed.
Now running V3.2 |
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JohnRicketts Occasional Visitor
Joined: Nov 12, 2006 Posts: 26
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Posted: Sun Dec 10, 2006 9:59 am Post subject: |
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Sallyann wrote: | dpmguy wrote: |
Sal, if you have a shielded coax is the shield attached to anything? |
No, that's the problem. It is an unbalanced input intended for a quarter-wave antenna to be directly connected. You will notice that there are no 'ground' connections available anywhere on the unit where you could connect a coax screen. This is standard practice, to avoid any earth loops that could cause a safety hazard under power supply failure conditions.
I can only suggest two ways to get a good signal: run a thin wire vertically up to the rear-view mirror (that's what we do); or connect via an isolating capacitor to the car radio's aerial feed (that's probably the best solution if you don't mind pulling the dashboard apart and opening up the cable)
Sal |
Having just hooked up to my fm car arial via a splitter, I'm not sure I understand this comment. If I'm right, the TMC plug is a combination TMC/headphone socket. The pin-out is (from the tip)
1 - left ear
2 - right ear
3 - TMC arial
4 - screen/0 volts
Soldering up the 4 way jack is a nightmare. I'n not sure if its down to the the higher melt temp of lead-free solder or what, but I had to do 3 plugs before I got one right!
John |
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Sallyann Lifetime Member
Joined: Jun 23, 2006 Posts: 768
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Posted: Sun Dec 10, 2006 11:24 am Post subject: |
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JohnRicketts wrote: |
Having just hooked up to my fm car arial via a splitter, I'm not sure I understand this comment. If I'm right, the TMC plug is a combination TMC/headphone socket. The pin-out is (from the tip)
1 - left ear
2 - right ear
3 - TMC arial
4 - screen/0 volts
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John,
I'm afraid you have got the connections wrong. Using your numbering, 3 is the common return to the earpieces and 4 is the aerial. That makes it easier to solder because you are soldering to a large tag instead of a tiny pin. Also there is room to hold the tag with pliers to act as a heat shunt.
Have you included an isolating capacitor in the lead to the car aerial?
Sal |
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