Jerry-rig My Broken Cell Phone

August 6, 2009 10:05 AM

How can I make a DIY cell phone antenna on a broken phone?

My antenna has snapped off my phone, but it works well most of the time. The signal strength has declined only slightly and only in some situations. I don't want to get a new phone, but would like better reception.Can I put foil in the hole? If it's hilariously 'ghetto' (jerry-rigged another term), the better.

It is a Motorola E815.

Here are pictures of the phone.

Picture 1

Picture 2

posted by sandmanwv to Technology (4 answers total)

Your pictures aren't working for me.

If the break is such that you can find a place where the existing antenna ends/breaks, you could try soldering a reasonably thick wire to it and using that. A friend of mine did that with a Nokia phone a long time ago and it worked okay for several years after.

(Alternatively, MeMail me... I have an old E815 I haven't used since I got my iPhone, and I'd be happy to get rid of it)
posted by olinerd at 10:14 AM on August 6, 2009

I got by for about a month using a paperclip as an antennae. I would keep it in my pocket and unfurl the clip as needed. Of course, it worked best for outgoing calls.
posted by samthemander at 10:28 AM on August 6, 2009

Antenna length is critical. The ideal length for a cell phone whip antenna is about 60% of the wavelength. (50% would be ideal if the phone was held exactly perpendicular to the incoming RF, but it almost never is.)

If the antenna length is 100% and is perpendicular, it will receive no signal at all. This is not a case where "more is better".

That length includes a long section of the antenna which is inside the phone. In your case that part didn't break off, and it's still working. That's why you can still use your phone.

I think the answer is that you go back to the phone company and get them to order a new antenna for you. Don't try to do this for yourself.
posted by Chocolate Pickle at 10:34 AM on August 6, 2009

Best answer: Cell phone antennas are heavily engineered, so you won't get something as good as the original. But you could try attaching a piece of copper wire the approximate length and thickness of what broke off. I'm guessing the only electrical connection it needs is to the little brassy/coppery bit at the top end of the slot it used to live in. Just fold the last cm of wire into a little springy hook shape and stick it in there. Then check whether you actually do get better reception with it than without it, because you might not.

Chocolate Pickle: 50% would be ideal if the phone was held exactly perpendicular to the incoming RF — I don't think that's what's going on. The reason that some lengths of antenna are good has to do with resonance within the antenna, not with whether the antenna's length matches the (vector-projected) wavelength of the radio waves. This is why things like chip antennas work at all.
posted by hattifattener at 10:58 AM on August 6, 2009