JeffTsai

iTrader: (1)

Ok, I have a couple of 2nd Gen GS's. It seems like the ones with the stock radio deck have strong reception. Stock decks have pretty strong everywhere and I don't really have many dead spots. However, the cars that have the aftermarket units have weak reception. I've had them all....double din, single, nav, Pioneer, Kenwood, etc. I currently have a Pioneer AVIC-Z140BH that I'm about to get rid of. Going to build another Car PC instead. But, anyways the problem is the same with all of them. All of the aftermarket decks have spotty radio reception. Like probably 60% as strong as the factory deck. When the radio signal is strong, then the sound is still nice and clear. It's when I go around some tall buildings or in areas further from the radio tower that I start to get static. The radio will drop out of HD Radio mode when the signal gets weak. When I get in the other GS with the stock radio, the signal is pretty strong and clear wherever I go in the city.

Anways, just seeing if anyone else here with aftermarket decks get weak reception on the radio. I have a possible hypothesis for this. The factory deck uses 2 radio antenna connectors while aftermarket ones only use the bigger of the 2 antenna connectors. Maybe if there's a way to merge the 2 antennas into the 1 connector then it will make the signal just as strong as the factory unit.

Debonair

From what I have read on the internet, and you know they can't put anything on the internet that is not true, the second antenna is for "Diversity Tuning."

A system utilizing diversity tuning consists of a specialized tuner and two antennas located on opposite sides of the vehicle. When listening to the radio, a special electronic circuit monitors the signal strength at both antennas and electronically selects between the stronger of the two. The speed at which this switching process occurs is so rapid that the listener does not even perceive that it has taken place.

Systems that incorporate diversity tuning have excellent multipath rejection. Multipath is that swishing sound you hear when driving around large buildings, structures, or mountains. It is created by the reflections of the radio signal reaching the tuners antenna a brief instant after the direct path of the radio signal. These multiple path (multipath) signals can vary from an in phase condition to one that is completely out of phase at the antenna. When the signals are out of phase, the quality of the reception is very poor. By using two antennas, it is extremely unlikely that multipath signals will be out of phase at both antennas simultaneously, thus assuring good reception at one of the antennas at all times.

This seems to explain why the aftermarket units, using an antenna on one side of the vehicle, get poor reception.

Bonjour.

GTE4Life

iTrader: (6)

I am not a radio guru but could you combine both antennas? maybe with a slpitter or something home-made so then your after market radio uses both antennas all the time? I am about to go aftermarket in my car and i really hope the reception is not greatly affected. Are there any tips or winning combinations of parts for better reception?

sakataj

iTrader: (182)

jeff.....before i buy my Avic-z150bh i will take that Avic-z140bh off your hands. you know i buy everything so im not kidding. let me know

also, ever thought about adding a aftermarket antennae?

LuxuryGS3

iTrader: (12)

Damnit Brian beat me to it!