# AM Radio "Signal Booster"? **URL:** \ **Category:** Factual Questions\ **Created:** [July 30, 2003, 8:15pm UTC](https://boards.straightdope.com/t/am-radio-signal-booster/191976 "2003-07-30T20:15:10Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![oceans\_11](https://avatars.discourse-cdn.com/v4/letter/o/b2d939/32.png) [@oceans\_11](https://boards.straightdope.com/u/oceans_11)\ **Post date:** [July 30, 2003, 8:15pm UTC](https://boards.straightdope.com/t/am-radio-signal-booster/191976/1 "2003-07-30T20:15:10Z")
Is anyone aware of a device that will increase my car radio’s capacity to receive weak AM signals, and/or dampen various interference? ---
**Author:** ![Brad\_Amundsen](https://avatars.discourse-cdn.com/v4/letter/b/dbc845/32.png) [@Brad\_Amundsen](https://boards.straightdope.com/u/Brad_Amundsen)\ **Post date:** [July 30, 2003, 8:33pm UTC](https://boards.straightdope.com/t/am-radio-signal-booster/191976/2 "2003-07-30T20:33:43Z")
No there is not a signal booster,but there are some things you can do to increase reception. see site/ / / / [http://www.geocities.com/SunsetStrip/Towers/3332/amradio.html](http://www.geocities.com/SunsetStrip/Towers/3332/amradio.html) ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [July 30, 2003, 8:57pm UTC](https://boards.straightdope.com/t/am-radio-signal-booster/191976/3 "2003-07-30T20:57:37Z")
There are boosters for _FM_ reception, but as noted there aren’t any for AM, at least in cars. The reason is that the AM antenna in a car stereo is internal, and consists of a soft ferrite rod with many, many turns of wire wrapped on it. There is no way to interpose a signal amplifier between the antenna and the receiver’s front end, like there is with the FM antenna. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [July 30, 2003, 9:11pm UTC](https://boards.straightdope.com/t/am-radio-signal-booster/191976/4 "2003-07-30T21:11:36Z")
I bought a antenna from the CCrain company that was advertized as able to boost AM radio signals. It did a little as I knew where I lost the AM signal before getting it and it was extended a little further. But really the difference was not enough. I have since replaced the car and have no trouble getting AM now (IIRC I still have that antenna somewhere). Some cars just get crappy AM reception IMHO. Also I had an interference problem on another car that would be really evedent on AM, I bought a kit that basically had an inductor and a capacator, itstalled the inductor - nothing, bought a 2nd kit for the constant power, installed the inductor - a little better, then installed both capacotors and it was much better, reception improved greatly and noise was elimiated. Also make sure your radio is grounded. ---
**Author:** ![oceans\_11](https://avatars.discourse-cdn.com/v4/letter/o/b2d939/32.png) [@oceans\_11](https://boards.straightdope.com/u/oceans_11)\ **Post date:** [July 30, 2003, 9:44pm UTC](https://boards.straightdope.com/t/am-radio-signal-booster/191976/5 "2003-07-30T21:44:44Z")
Doh! I guess I’ll live. My reception is fine, I suppose, but I was just looking to get a little better quality when I’m driving through the mountains or underpasses. You’da thunk that as “low tech” as AM radio is, someone would have come up with a nice, simple solution. Thanks for the info! ---
**Author:** ![bbeaty](https://avatars.discourse-cdn.com/v4/letter/b/c0e974/32.png) [@bbeaty](https://boards.straightdope.com/u/bbeaty)\ **Post date:** [July 31, 2003, 6:51am UTC](https://boards.straightdope.com/t/am-radio-signal-booster/191976/6 "2003-07-31T06:51:09Z")
The car radio is pretty well shielded. I bet it picks up AM waves via its antenna rather than via its ferrite coil. Yes, the antenna is much shorter than a half wavelength. But so is the ferrite coil. If the RF energy comes in via the antenna, then you should be able to increase AM reception by increasing the “electrical aperture” or just the length of the car antenna. Connecting two antennas together should give some improvements, but not as much as doubling the length of a single antenna. ---
**Author:** ![oceans\_11](https://avatars.discourse-cdn.com/v4/letter/o/b2d939/32.png) [@oceans\_11](https://boards.straightdope.com/u/oceans_11)\ **Post date:** [July 31, 2003, 1:13pm UTC](https://boards.straightdope.com/t/am-radio-signal-booster/191976/7 "2003-07-31T13:13:02Z")
**bbeaty** - are you saying I need a six to eight foot antenna?