I don’t know if this is common knowledge, but for anyone that wants to increase the range of his remote (RF) transmitter, the type used by car alarms or even garage doors, can do so - immediately and, best of all, at no cost. Of course, this method will not work with IR (infrared) transmitters, but only with RF (radio frequency) transmitters, which are much more common.

Simply hold the antenna end of the remote (transmitter) - this is normally the end opposite the key chain attachment point, against your body and transmit. For example, “point” the transmitter touching your forehead, or any other part of your body.

The reason this increases the transmit range is because your body will become capactively coupled to the transmitter, in effect acting as an antenna, which is much bigger than the little printed circuit board antenna inside the remote (matching wavelengths with antennas is not relevant here - suffice it to say that it works). This is the same principel that is used when transmitters (e.g. vehicle cell phones) are connected to antennas mounted on glass. There is no direct physical (i.e. wire) electrical connection. The RF (radio frequency) is coupled capactively to the antenna through the glass.

Transmitting my remote the normal, or common, way (“pointed” toward my vehicle - antenna end toward the car, key chain side toward me), I get a maximum range of ~120 feet. Transmitting with the remote “pointed” touching my forehead, I got to ~300 feet until I ran out of room; I was up against the woods. Besides, it was getting more difficult to see the parking lights coming on telling me when it was receiving the signal, so I don’t know what the maximum range was. But the range was easily increased by over 150% using this method.

As a side note, my range increased from 43 feet to ~120 by simply relocating the receive antenna from under the dash where it had been installed, to run along the body “A” arm and back above the window (below the plastic molding). Increasing the antenna height and getting it closer to the window (less metal as compared to under the dash) is the reason.

 

Hmmm, I have thought about re-routing my antenna wire....

Im gonna try the weird "use yourself as a transmitter" thing the next time I go out to my car!

 

Yes, using a separate glass-mounted antenna definitely improves things a lot. Nearly all remote car starters us these.

Most standard car alarms have a 12" or so piecce of wire coming from the brain; this is the antenna. Make sure not to cut (or lengthen) this wire. Also, make sure it is straight (zip tie it along another wire harness) and not curled up into a roll.

My friends sometimes hold the transmitter under their chin, and most of them say that it does increase the range.

Another thing for all to keep in mind...the alarm transmitter only has such a small antenna (or no antenna at all) because it has to be small enough to fit into your pocket.

Other products, like radios and television sets generally are pre-made with the proper size antenna. Putting a 10' whip antenna on your car radio would actually make reception worse, not better.

 

Chris, I also hold the remote under my chin... works great. It's fun to tell people to do when they're out of range... they think you're crazy (or trying to embarass them), until it actually works.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

And what's great is that you look REALLY cool doing it too! I had a buddy that thought he was impressing us every damn time he did the chin trick...

MILT

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'83 HOmaro--doesn't run
'92 Bird--burnt to a crisp
'78 T/A 400--fast, Burt Reynold's style
'83 Buick LeSabre--the Ghetto Cruiser

"Without evil there can be no good, so it must be good to be evil some time!"

 

Is that also why radio reception is improved when you're closer (or touching) the antenna?

 

Good trick. I'm gonna try when my car is up and running again.

 

How come there is a difference between holding it in your hand and putting it against your body? Don't they both accomplish the same thing?

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82 z28 350cid, vortec heads, comp 262h cam, Holley 600cfm carb, 2in twice pipes, MSD ignition, turbo 350 trans, 3.73 posi, manly b&m megashifter

 

82Z,

I presume that you mean holding it in your hand and pointing it toward the receiver instead of pointed toward and touching your body. Yes, the results are dramatic. The reason was given in my original post (the transmitter is capacitively coupled to your body, increasing the antenna area, thus increasing the signal strength).

If you don't believe me, try it yourself. See how far you can access the receiver doing it the conventional way (remote pointed toward the car). Now, try it the way I described in my original post (the end of the remote should be touching your body, it doesn't matter if it is pointed away from the car - if it is not touching your body, range is dramatically reduced). I would expect an improvement of range of well over a 100%.

I don't think it matters where on your body the remote is touching. I used the forehead example in an attempt to be clearer.

I've taught myself to be more discrete by simply touching the end of the remote against myself inside my jacket pocket. This probably works just as well as the chin/forehead method, which probably would raise at least a few eyebrows (if you care what other people think...)

[This message has been edited by Stuart Moss (edited December 23, 2000).]