Improve Radio Reception

**gilcoolcruiser** · December 13th, 2010 05:45 PM

Originally Posted by xmax2010

sir i have my 3 week old sportivo poor reception din sa RADIO hindi matanggal ang hisssing sound, ang sakit pakinggan. have you solved this kind of problem?

Iyan na ata ang sakit ng crosswind HU mahina ang reception sa akin din 2 months pa lng kahit nasa manila wala kng maintindihan sa pinakikinggan mo.

**oj88** · December 13th, 2010 07:26 PM

Get ready for a bit of long read... :D

There are a number of reasons for poor radio reception. Off the top of my head, reception problems may be caused by any combination of the following:

Distance from the radio station or transmitter
Obstructions - man-made structures or topographical (ie. valleys, mountains)
Bad placement of, or broken, antenna (wrong wavelength, wrong orientation)
Broken or loose antenna cables or connectors
Defective/disconnected pre-amp or signal amplifier (where applicable)
Weak receiver sensitivity
Man-made radio frequency interference (RFI)

Most modern cars have antennas as an integral part of the windshield. Though this makes for a cleaner-looking and a much sleeker car design, it is one of the worst place to put an antenna. In principle, antennas must be installed as high as physically possible to clear the obstructions that the car itself present (ie. passengers, A,B & C-pillars, roof, etc.), and that the antenna itself must be of proper design (precisely cut for the frequency band it will be used for) with good quality cabling and hardware.

As I learned during my amateur radio days, the best place to put an antenna on a car is at the center of the roof since it is usually the highest point of the car and that the roof itself (as part of the chassis ground) provides for an excellent ground plane. But this may be considered as either impractical or unsightly by modern standards. Some do have OEM antennas on the roof near the front windshield (ie. Hyundai Getz) or near the rear windshield (Honda Jazz), and this is as far as perfect placement goes nowadays.

Going back to the windshield antenna, car manufacturers are aware of the inherent limitations of this design, so they tried to work around the problem by adding signal amplifiers to boost the reception. The problem is, everything is boosted up; the RF signal AND noise/interference or RFI. Thus far, there's nothing much that can be done but either drop the OEM windshield antenna and use an aftermarket one that you can have total control on placement, or replace the OEM radio with something that has a bit more quality in the receiver circuitry (ie. good sensitivity, high noise rejection properties, very good signal-to-ratio or SNR, etc.)

Another thing, broadcast FM transmitter antennas since after WWII have been designed to be vertically polarized. Without going into the itty-bitty details, suffice to say that the receiving antenna must be oriented vertically to capture as much energy from the transmitter as possible. The reason I mentioned this is that, a lot of those A-pillar collapsible antennas when extended, will almost always bend downward until they're practically horizontal. As such, it may not be as sensitive when receiving distant or weak FM stations.

Finally, the AM-band receiver antenna coil is usually built into the HU chassis. AM signals travels further than FM signals and does not require line-of-sight due to its longer wavelength, so it really doesn't need an external antenna. Reception performance in this case lies on the HU's receiver sensitivity.

**speed unlimited** · December 13th, 2010 08:27 PM

Replaced with a better antenna.

**Benzmizer** · December 13th, 2010 11:45 PM

Play CD/DVD.

**olidotcom** · December 14th, 2010 12:03 AM

Sir OJ... 10-73's to you.. hehehe... HAM user din ako dati...

not sure if this can help, but it did on my old lancer itlog... stuck a wire either from the antenna itself or from the wire in the radio where the antenna is connected then i grounded it to the car body. (so parang dagdag ground yung body ng car as the antenna)