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Why does the 2-to-1 radio antenna degrade the signal quality of the RCD330 PLUS
Some friends purchased RCD330 PLUS. Don't know how to choose the antenna 2 to 1 adapter. Now let me tell you.
Usually , your original head units were RCD310, RCD510, RNS315, RNS510. These units are dual antennas. However, RCD330 PLUS is a single antenna. Some customers think that if both two antennas can be connected to RCD330 PLUS, there will be a good radio signal. This is wrong.
s Some friends from Canada and the Czech Republic have verified that Using a 2 TO 1 antenna adapter will make the radio signal worse. Let's analyze it now.
The original dual antenna was composed of AM / FM1 and FM2. The purpose of FM2 is to improve the signal quality of FM radio stations, including TMC reception.
Therefore, in RCD310, RCD510, RNS315, RNS510, there are two independent radio antenna systems. The RCD330 PLUS is a single antenna system that integrates FM and AM.
If we mix AM / FM1 and FM2 antennas directly with original antenna, the signal quality of the radio will be reduced. This is equivalent to connecting two antenna systems for RCD330 PLUS in parallel, and the two systems will interfere with each other.
Therefore, I recommend choosing only one antenna. In 2016-2018 Jetta and Passat produced in China, they installed RCD330 PLUS using a single antenna. Only MIB Ⅱ navi with navigation system can connect two antennas.
So, I think you only need to connect one of AM / FM1 and FM2.
If you cannot get a radio signal on one of the channels, you need to change to the other channel, as follow video guide.