AM/FM Antenna Booster

correct. the only thing that helps is a better front end in the receiver.(short of improving the antenna). The point is you cannot amplify a signal with out amplifying the noise. So the carrier to noise ratio remains the same. Stock radios have had for years superior front ends than the after market product.

Thanks for the info.

There is two FM radio stations that are just out of reach for me. One is only a matter of about five or six miles. I wonder if a cheap amp would help me receive that station?

Once again, your post was very informative.......Thanks.

An inline RF amp will only help you if the sensitivity of your receiver is low. Most modern FM receivers (last 10 to 20 years) have very good sensitivity so the amp is unlikely to help you as it will amplify the noise and signal making it difficult for the receiver to lock onto the carrier. A better antenna may help you, especially if you are in a stationary position. A half-wave folded dipole would definitely help you but you will also need a 300 ohm to 50 ohm balun to go into your coaxial antenna input. A 300 to 75 ohm used for TV would work well enough and is readily available at electronics stores.

http://www.amazon.com/Parts-Express-FM-Dipole-Antenna/dp/B000M9EREE/ref=pd_sim_e_1?ie=UTF8&refRID=1BGD67YYY0AB4QB914T8

Here's the balun

http://www.amazon.com/Parts-Express-Push-On-quot-Balun/dp/B0002ZPIOQ/ref=pd_sim_e_1?ie=UTF8&refRID=1AP2GNW12TPWYFEF7S4J

And the "F" to RCA adapter

http://www.amazon.com/Monoprice-104130-Female-Adaptor-Plated/dp/B001VL9SQE/ref=sr_1_1?s=electronics&ie=UTF8&qid=1428453990&sr=1-1&keywords=f+to+rca+adapter

Good luck with your quest.

A significant problem with small or low power signals is poor connections. One wouldn't think that an antenna wire connection was very significant. After all, the current into it is on the order of picoamps. The problem is that contact resistance can interfere with these little currents in a big way.

Twist on connectors usually work but they can also be the problem. Solder fixes a lot of sins. In high frequency RF, such as radar circuits, I sometimes had to coat a connector with a mixture of silver dust, some fast drying solvent and a conductive bonding agent to keep energy from leaking out around the threads. FM won't require that kind of treatment. You may have the right kind of cable, just poor terminations.

A cheap directional antenna would be a better investment, for reasons that have been explained fully above.

A great idea, when parked.

Or if your travels outside of the 'normal' listening area run more or less along the same bearing with the transmitter. Then you could could orient the directional antenna appropriately. And with a folded-dipole, you have two beam patterns, 180 degrees apart for when you are headed towards the city and then home again.

I used something that looked like this http://www.solidsignal.com/pview.asp?p=bf-8809 from the 80's to 90's and it worked very well. The front-end of the car radio was designed for an ant amp, but it wasn't used. Only 2 or 3 stations would stop at scan mode before using the ant amp.

I used cheap antenna boosters in the 70's and 80's that brought in many more stations just as you say. Not even expensive ones either (you wanted quantity of stations not quality in those days!!!).

Some I cobbled together from a few components myself.....no high and figh!!! They mostly worked really well.....

Mostly on car radios probably of dubious quality. But they worked!!

The best car radio I ever had I made from a cheap kit, but it had no cassette and no FM.....but press buttons with tuning, REALLY MODERN then!

Today it would be considered vintage and great for cars of that period.....

Look here if you are up to a bit of soldering:-

Car Radio Antenna Boosters 1

or

http://www.electroschematics.com/tag/antenna-amplifier-circuits/

You should blame the FCC, they're the ones that mandate how far from the transmitter you should get a readable signal. Once you fall out of that range (yes, 5-6 miles is all it takes, and terrain matters), you may find yourself between service areas and your radio hears two competing low level signals on the same center frequency. The circuitry can't decide which one to decode so depending upon the design and age of the receiver you may get noise or silence.

Adding a signal amplifier boosts all signals equally so you're still stuck with the same problem of which one to lock on to. Some radios can be switched to Mono mode and that often adds a few miles to the range because a Mono signal is easier to decode than a stereo one.

Went around and around with my Car Radio store, and he basically said that he just tells everyone to get a Sirius radio -ready unit, and buy the subscription… They have multi unit pricing (home, boat, 2 cars etc.) My 2 cents….

I still feel that small, inexpensive amplifiers, even a DIY one maybe, may bring in the stations you mentioned that are just out of range for you.

As many here (correctly) have said, the noise will probably be also amplified as well, though there are amplifiers that function a little like a radio and are tunable for one or more areas of the wished for band.....they tend to be slightly better I am told. No personal knowledge either way, sadly.

But anyone wishing to have really Hi Fi in his car (as far as that goes with driving etc.) really needs to take his own CDs with him I feel...........even then it won't have any relation to your own lounge at home...Though you did not mention that "quality" was paramount.....

As I see it (hopefully!), you are really just wanting to hear these stations, even if quality suffers slightly. So the amplifier idea is quite reasonable......I looked around and found several on offer all over, most very reasonably priced, as you may have seen as well.

Something I did in the 70's, which may not be applicable today, was to buy a fiberglass car aerial that was about 6 foot long (if they are still available!), which improved the medium and long wave reception dramatically (I do believe I had no FM on that radio!!).

But it could theoretically also reduce the noise level in any FM signal......but I am guessing only.....

They were then a very cheap option and came with a special clip to stop it whipping about in use......(I could not find one for sale anywhere today).....helping in the long and medium waveband does not mean true improvement for FM, but you could test/try using a long piece of wire, while parked at home and see if there is any improvement on a faint/noisy station near to the ones you want to receive....that may give you some "food for thought!"

I did find this explanation that may help you a little:-

http://www.termpro.com/asp/pubs.asp?ID=113

Also, have you looked to see if the stations you wish to hear are also on "DAB"? (not all countries have this yet!!)

A cheap ebay, portable DAB radio could help find that out (and be useful for Picnics and the like!!)....if good, then you somehow need to add a DAB receiver in your car.....and attach it to the present radio as a stereo input maybe!

All I have written here is simply all theory only, but hopefully it will give you some further ideas......Best of luck!!

Thanks for your thoughts Andy.

Yes, you are correct when assuming that quality is not my top priority. I think I am going to try a cheap amp for the antenna. I will let everyone know how it comes out.

I am also looking for an antenna that is twice the length of my original, that scews into the base.

Do try the cheap method I mentioned first using simply a long (a couple of meters) piece of copper cable that you may even have laying around in the garage, just to see if "longer is better!" first.

I just remembered, since my last post, that to improve FM reception in my Caravan (15 years or so ago when I added a CD Car radio unit!), I laid a piece of mains cable, 3 cores bound together, around the back of the cupboards in the front of my caravan and simply that brought in dozens of stations on the FM band, even though it is all behind the Aluminium skin of the caravan, and basically therefore heavily shielded....

Usually, when installing a radio in a caravan, you would need to bore a hole through that metal skin to add a car aerial....a possible place for moisture to eventually enter the van.....I wanted to avoid that if possible. It was!!

So a longer antenna may help you without the amplifier.

Not to worry you, as I think it will simply work for you without any problems, but if you do add the amp, add it as close to the base of the antenna as physically possible, to amplifier more signal and less noise. But of course, inside the car.

Also, an amp with variable gain (if such a thing even exists!) may help if you start picking up any of the many sources of noise that sadly a car can produce, though there are suppliers of quality components to alleviate such problems as alternator whine for example. Cheaply too.

Though in my experience, most modern cars generally produce far less problems than we had in the 80's and earlier.... if any at all.

Cars less than 20 years old with computer management systems/ECUs will usually produce little or no problems for a modern car radio.

I cannot remember exactly when I last had such problems myself, but at least 30 years or more ago....

As several others have indicated, after-market signal amplifiers are not very effective since they amplify the signal and the noise. It still may be possible for you to improve the reception of the radio without an external signal amp.

The antennas must be the optimum for the location and the radio. Vehicles normally use what is called a "whip" or "windshield" antenna. On a vehicle the most important things are: location of the antenna, type of antenna, coax and terminals, and settings of the radio adjustments. I often remove vehicle radios and set them up in my shop mounted on a 20"x30" piece of sheet metal as the ground plane. Experiment with different antennas for the radio you need setup. These should be mounted on the vehicle in the mounting hole for testing. On the top or bottom of most radios there is a hole with a screw headed tiny shaft located inside at that location. Either follow the manufacturer's directions for tuning or else connect everything, put the radio on your favorite station and adjust that screw until the sound is the optimum. It usually works and improves the reception.

I live almost equidistant between two metropolitan areas right at the fringes of each reception area. Some car radios won't pick up either location and others will pick up both more than 15 miles into the other's fringe area. Just experiment a little.

Also see--> http://www.termpro.com/asp/pubs.asp?ID=113

The best radio I ever had was in a '95 Dodge 1500 p/u. I improved the reception simply by adjusting the radio's rf amplifier while in the vehicle. Took the radio out when son got "T"-boned and mounted a different antenna on the aforementioned sheet metal in the shop. Connected to a power source, adjusted the rf and I had the best vehicle radio ever.

Do some experimentation with the antenna and the rf amplifier. It should improve the reception. If not, try a different radio. Optimize what you have and not just amplify the signal and noise.