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Jeff Liebermann Jeff Liebermann is offline
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Default Using headset as cell phone radio antenna.

On Fri, 27 Jul 2012 12:39:12 -0400, micky
wrote:

I meant get an actual Huawei headset, but I gather I don't need that.


No. Except for the shielded wires, every headset that I've tried
works as an antenna. You can also make or buy an adapter that works:
http://www.tested.com/news/feature/2292-how-to-make-any-pair-of-headphones-smart-phone-capable/

It would be helpful if you
would kindly disclose the maker and model of your phone.


Of course. It's a HUAWEI Fusion U8652, sold mostly by AT&T under
their brand. It has stereo radio with RDS I haven't got the phone
yet, it's still being shipped.


http://www.gsmarena.com/huawei_fusion_u8652-4656.php
3.5mm jack. However, I goofed. I can't count wires:
2 wires mono EP
3 wires stereo EP
4 wires some earphones with microphone and possibly PTT.
5 wires defacto stereo earphones, with microphone.
If you buy a headset for your smartphone, it will be a 5 wire
connector as shown in the first URL above. However, you can also just
plug in a 3 wire stereo earphone, as you don't need a microphone. Make
sure that they're somewhat high impedance (40 ohms) as I don't think
the phone has the power output to run a pair of 8 ohm earphones.
All are high impedance so that the cabling requirements are minimal.

RDS isn't used very much in the USA. Very little RDS, RDS/RT+,
or eRDS. At best, it will display the station call letters and the
tune being played. Nifty stuff like weather and traffic reports are
usually done using HD Radio PAD data channel.

Maybe for us that would make the difference. Maybe we could each buy
one of those rubberized cases for the back, and coil it around in
there, relying on induction?


No. You'll never get throug the shielding inside the case.

It should be 300,000,000 / 88,100,000 meters long? Or half that?
About 4 feet? Or 1/4 of the first number, 2 feet? I"ve never heard
of 1/8th wave, but maybe that works too? 1 foot?


Sigh. FM broadcast is at 100MHz.
One wavelength at 100MHz is about 10ft.
Each side of the dipole is 1/4 wavelength long.
Therefore, the antenna and counterpoise should be 2.5 ft long.

My Droid X FM radio application didn't have a signal strength meter,
so judging improvements in antenna design was rather subjective.

Good luck.


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Jeff Liebermann
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