Jeep Wrangler - Restoration & Custom Outfitting
All photos, diagrams, and text on this page © Copyright 2013 - David Todeschini - all rights reserved - see Copyright Terms
Bogus AM / FM Radio Signal Booster
Ripoff Report has been filed
Before I begin this article, I
want to advise my readers to read through this entire page and follow
the hyperlinks. Many people think they need a signal amplifier because
they experience noisy radio reception, and in reality, the problem may
be noise induced by the vehicle itself, or due to improper installation
of high-powered audio amplifiers or equalizer equipment.
I am in the
process of adding a
that will help you to correctly identify the problem, so that the solution
you choose is the correct thing to do.
ANY audio equipment, it is important to run a separate heavy-duty ground (–) wire
to the battery, and not just attach negative wires to the vehicle
chassis. If you install a signal amplifier on a vehicle that has an
electrically noisy electrical system, you will invariably make the problem worse.
It is therefore very important that you correctly identify the problem
before you attempt a "solution". This article (and those referenced with
the hyperlinks) hopefully addresses all possibilities.
BASICALLY: You need a
signal amplifier if the radio station you want to listen to is weak, or
fades in and out while the vehicle is standing still with the engine
off, AND the CD / DVD / iPod (aux jack) is functioning properly
regardless of whether the engine is on or off. You
need to run a separate heavy-duty ground wire to the battery negative
terminal if your CD /DVD / iPod (aux jack) is picking up hum, static, or
high-pitched whining with the engine running.
some of you have correctly identified the problem as a weak radio signal
in a fringe area, or not enough gain from a shorter antenna you might
have installed to make your Jeep more "bush-worthy", but have attempted
to fix that problem with a BOGUS solution; a piece
of equipment which, according to one eBay seller's store page, has sold
over 2,000 units from that one seller alone at $3.89 + S&H – (do the
math; that's $7,780 for this one seller alone!). eBay has at least 186
sellers for this "device", ranging in price from $2.59 to $6.21. Others
on the Internet are charging $25 or more.
THOUSANDS of these units are being sold by sellers all over the
Internet, and even on Amazon. No doubt, many of these sellers are not
aware that the product is a ten cent P.O.S. that
doesn't work, and contains no components that could be called "signal
amplifier" or "signal booster" in any sense of the word.
Many people have
devoted hours to installing this thing, and some have convinced
themselves that it made a difference because they invested so much
effort into its installation, but it is
that the device can amplify a radio signal, because there are
NO TUNED CIRCUITS,
in the device at all.
If you installed a
short radio antenna or rubber "trail antenna" on your Jeep to prevent it
thrashing about as you drive on back-woods trails, or are simply in or
traveling through a fringe area where your radio reception sucks, there
IS a solution to the problem, but it
$3.89 piece of crap advertised on eBay,
which is the
same piece of junk you can get from Amazon
and from a host of other sellers on the Internet.
For a few bucks, I
figured "what the hell? It might work", and without knowing
precisely what it was made of, out of curiosity, I ordered one.
A signal amplifier has nothing to do with eliminating noise caused by
the alternator or other components in your vehicle. An RF (Radio
signal amplifier is designed to operate on a specific band of
frequencies, and it requires tuned circuits and transistors or tuned
circuits and integrated circuits. This is the least of what I expected
to find in the "amplifier" built into the aluminum tube (see
video below). When I received it, the thing looked a bit suspicious, so
I disassembled it and cut off the heat-shrink tubing on the circuit
board inside. All I found inside was a 10uFd, 25WVDC capacitor and two
resistors on a circuit board.
circuit might filter out some alternator whine, it is definitely
amplifier of any sort. In addition, the Working Voltage (25 Volts) on
the capacitor is much too small; voltage spikes on the vehicle's
electrical system could cause the capacitor to short out, and while in
this circuit, a shorted capacitor is unlikely to start a fire, your
radio reception if this happens will suddenly be next to nothing. I
traced out the connections on the circuit board, and used a
to measure the value of the resistors. The
diagram for the thing is
If your radio suffers from "alternator
whine" – a high-pitched
noise which is audible when listening to AM stations with the engine
running, installing a
signal amplifier will make the problem orders of magnitude worse. If you
are getting noise in your AM radio, or buzzing, whining, or high-pitched
squeals in your speakers, there is a
very good troubleshooting guide here,
technical discussion from Ham Radio Operator KOBG.
If you have a high-powered
amplifier (say, in the trunk, or rear of the vehicle), and you have
grounded that equipment to the chassis (–) at that point instead of
running a separate heavy-gauge wire to the negative terminal (–) of the
battery, the noise may be caused by a "ground
You need a SIGNAL AMPLIFIER if
your radio reception is poor due to your being too far from your
favorite station, or if you installed an alternative (short or rubber)
antenna, and are now getting crappy reception (when it was fine
NOTE: You cannot just cut a
whip antenna to make it (conveniently) shorter and expect it to work. An
antenna's length is TUNED to a fraction or a multiple of the
frequencies of the
radio. Cutting an antenna to a "convenient" length arbitrarily will ruin
the SWR (Standing
and your reception will suffer as a result.
BOGUS ANTENNA "AMPLIFIER"
This ad from one of several dozen sellers on eBay does not guarantee
improvement in performance for this device. Some sellers an eBay are
charging $27 or more for this identical piece of crap.
Another seller on eBay provides photos of the inside of this device,
which is identical to the one I have except for the addition of a
disk capacitor (which does not make this an "amplifier") marked by
the red arrow.|
I purchased this item
on eBay looking
for a signal booster for my Jeep radio, because I have a short
"trail antenna", and live in the New Jersey Pine Barrens which is a
fringe area for the stations I like to listen to. I am a retired IBM
engineer, so before I tore my dashboard apart to install this thing,
I opened it up to see what makes it "tick".
Well, a 10 microFarad
capacitor and two resistors (see photos,
video, and circuit diagram,
below) do NOT constitute a "signal amplifier" of any sort, and so
the advertisement on on eBay and on Amazon (shame on you, Amazon,
for not quality checking your products) are
The guy who
(supposedly) reviewed this thing on eBay saying
that it boosted his reception must be
the placebo effect or
he's smoking something really good,
because such circuitry CANNOT POSSIBLY boost any signal. The most it
could possibly do is filter out some alternator whine (on AM
signals). It is more than likely this guy (if he's real)
inadvertently fixed a loose antenna connection while installing this
There is also
another "variant" of this thing sold on an
overseas vendor's Web site that completely drops the pretenses
of an aluminum cylinder (which would presumably contain the
'amplifier' circuitry), and provides a male / female connection for
the antenna, and a wire that connects the 'hot' side of the antenna
directly to the vehicle's (+) positive battery terminal. If
connecting through resistors (or inductors, as above) is a bad idea,
THIS is even worse.
of the BOGUS "Signal Amplifier"
specifications for this unit on eBay read,
"Car Antenna Radio FM &
Am Signal Amp Amplifier Booster", and on Amazon read,
Antenna Radio FM and AM Signal Amplifier Amp Booster", it is by no
stretch of even a highly intoxicated imagination, an "amplifier" of
any sort. I bought this thing on eBay, and just for principle, I am
filing a dispute for "not as described", demanding my money back
from the seller, and when you watch the videos below, you'll see why.
of a BOGUS device
See this video on YouTube:
(I also posted this video on Amazon):
Rebuttal to Ripoff Report Rebuttal
that says resistors are inductors and that device works as claimed.
See this video on YouTube:
video, I cut open one of the "resistors" with a
Dremel Stylus Tool.
It is a wire-wound resistor or small inductor.
See this video on YouTube:
I have ordered ANOTHER one of these things from a different vendor
than the one I got the original one from. What I want to see is if
there is any difference (I know it's the same device, I just want to
prove it to my readers), and I want to ACTUALLY INSTALL one of these
things in my Jeep and produce a video demonstration that this device
has no effect in reception (it cannot, because there are no RF-active
components), and puts 12 Volts on your antenna mast.
"Should rate below zero. This radio signal amp - booster does not
work and it cannot work because it has NO amp circuit. I am a BSEE
and this has only 2 resistors and 2 capacitors - it can't boost
anything - impossible.
It is low cost so its not worth shipping for a refund - so DO NOT
buy this thing unless you want a lighter wallet. Any other reviewer
that says otherwise thinks it works but it can't. If this scam
device sells a few hundred thousand at 5 bucks that's a million
dollar scam for a POS to these crooks. You need transistors or an IC
to make signal gain - look elsewhere."
it in and no difference at all. I couldn't tell any change in it.
All the stations come in at the same as they did without."
EBAY REVIEW (what is this guy smoking?):
"Both my factory and aftermarket unit were having trouble pulling in
more than 10 stations in my neighborhood, a lot fewer than the 20+ I
used to get in my old car system. All I had to do was install this
unit between my antenna adapter & aftermarket unit, splice the power
cord into the accessory power line, and all of a sudden I'm getting
a lot more stations (including 3 low power stations I didn't know
existed), and its easier to get HD radio signals on the ones I had
before! Great Product!"
: I will not quote
verbatim, since the rebuttal belongs to Ripoff report, but you can
read it by clicking the link (above). The person attempting to
discredit my review said that the two "resistors" I said were on the
circuit board were actually "inductors". Be that as it may,
resistors or inductors, the circuit cannot POSSIBLY work, and
if these two components ARE inductors as he claims, what this
circuit does is connect your car antenna (mast) to the positive (+)
terminal of your car battery through two small coils of wire. In
that case, you would be lucky not to burn out your radio receiver
"front-end" with 12 Volts applied to the
antenna. In that case, if the antenna
mast ever touched the body of your Jeep (or car) the current
through two 18 Ohm, 1/2 Watt resistors = 12V / (18 x 2) = 12 / 36 =
0.33 Amps. At 12 Volts, 1/3 Amp = 12 / 3 = 4 Watts, which means
those two inductors (wirewound resistors) that have 18 Ohms of resistance in the guise of
1/2 Watt resistors would instantly go up in smoke, and if it were
not for the aluminum tube around the circuit board,
it could set your Jeep on fire. You
would DEFINITELY smell the smoke if that happened, and you'd go
BONKERS (and possibly spend a fortune on a mechanic) trying to
figure out where the stink is coming from.
I filed a dispute with the seller and he
wanted me to send this thing back to receive a refund. It would cost
me more to ship the thing (plus the time & gas to go to the Post
Office) than the refund was worth, so I stopped communicating with
the seller and escalated the case to a dispute on eBay, and filed a
dispute with PayPal (eBay owns PayPal).
Not that $3.89 (+ shipping) will make or break
me; it's the principle of the thing. After filing a dispute with
eBay claiming "item not as described",
and providing a link to this page in the dispute, I received a
refund of the purchase price AND the shipping
having to return this piece of junk which I destroyed in the
above video to
prove that the device is bogus. If you have bought one of these
things, I suggest you remove it from your vehicle if you installed
it, and (also) file a similar dispute referencing this Web page. The
refund won't make you rich, but it will send a message that YOU
cannot be micro-scammed.
Because of its obviously DECEPTIVE
marketing (whether intentional or out of ignorance on the part of
the seller), this device has earned the USDA Grade A Bullshit seal.
At this point, we have NOT found any device
that is suitable for improving radio reception that is a true "amplifier"
that affects the strength of both AM and FM signals when inserted
into an existing antenna connection. The ability of
a radio receiver to "pull in" weak stations is primarily affected by
two things: The location of the antenna relative to the broadcast
station, and the sensitivity of the receiver's "front-end" (which is
tuned circuitry built into the radio itself). Any amplifier that
would affect AM signals would also amplify alternator whine and
electrical noise in the area (such as would be caused by overhead
high voltage lines) We are actively
looking for an external device that would solve this problem, and I
will make a video of the installation in my Jeep.
If you are not
satisfied with the performance of your radio reception, there IS a
low-cost option: REPLACE the antenna with a TRUE amplified antenna
that mounts on the inside of your windshield. In the alternative;
albeit a more expensive alternative – is to get a new windshield
with an antenna built into it. The low-cost alternative will cost
you a bit over 4 bucks, and the installation is easy. Here is the
link to where you can get it:
If you need to replace a long
antenna with a shorter one, here are some alternatives.
If you've cut the
long whip antenna you have to an
arbitrary length, your poor signal reception is at least partially due to the "hacked"
antenna not being tuned to the proper wavelength. Replace your
antenna with one of these.
Depending on the type of noise problem you have, there are a myriad
of solutions available. Before you order any filter -- especially if
it taps into the audio cables -- research and determine what your
problem is, and what components are at fault. In any event, anything
that looks like the BOGUS AM / FM "Amplifier"
in the video on this page, is absolutely
useless and a complete waste of money and time.