iolmaster

iTrader: (1)

I have spoken to three Lexus dealers and the consensus is that the rear power antenna is used only for the AM reception. The FM antenna is in the windshield. Since I never listen to AM, I am wondering how easy it would be to disconnect the motor to the rear antenna. Fuse would be nice.

R052822

I think they are very very wrong. But hey, I have a SC430 European version. Things are all different over here. Maybe the antenna's are reversed over here in the Netherlands.
If I switch to am the rear antenna goes down if I switch to FM it goes up.
On my RX the antenna mast did not came out all the way due to corrosion and street dirt. Bad FM radio was the result.

So ....

VVTiBob

Should be the 10A Radio NO.2 fuse located in the passenger side fuse junction box, behind the kick plate. Center column fifth from the top. But I don't know what other circuits, if any, are run through this fuse, so I guess it'll be remove it and test. If pulling the fuse does not work, you could disconnect the antenna mast power at the auto control relay located back by the mast itself.

Habious

The rear antenna for-sure is for FM...it even adjusts length depending on your radio station dial. It can be hard to notice it doing this as you just just up and down the dial, but if you make a significant jump all of a sudden...like go from 88.1 DOWN to 107.9, you'll hear/see it adjust in length.

iolmaster

iTrader: (1)

OK then tell me what the antenna in the windshield is for? It is not the GPS antenna. Normally an FM antenna is dipole not monopole like the mast at the back. Again, I had three different Lexus dealers tell me the same thing. Flow in Greensboro, Richmond Lexus and Barker in Virgina Beach.

VVTiBob

Well the following statement is in my FSM "2002 New Car Features SC430" manual:

"In addition to the rear pole antenna, which serves as the main antenna, a sub-FM antenna has been embedded in the front windshield to improve reception sensitivity."

Take it for what it's worth, you can certainly test radio reception with and without the rear antenna extended.

Harold57

It is not uncommon to have two antennas for a radio band (FM in this case). If one antenna is getting bad reception, it can switch to the other one. RF reception is very location specific and that location is commonly dynamic (so it can move). If they really want to get fancy, they can attempt to bring both signals in and combine them, but that is really difficult to do properly without causing more interference than it is preventing.

iolmaster

iTrader: (1)

May be true, but I doubt that Lexus has something like that implemented in a car.

Bob, how would you test with the mast collapsed? Take out the fuse you indicated?

VVTiBob

Well, yes, remove the fuse with the car ignition off and mast collapsed. Then turn the car on, then the radio on to see if mast extends or not. If the mast remains in its stowed position, test all the other electronics to make sure nothing else runs on that same circuit. If all is as expected, begin tuning into various stations, using your ears as the measuring device on reception quality.

Worse case put the fuse back in with the car ignition in the off position and you're back to where you started.

iolmaster

iTrader: (1)

Thanks Bob, I will do this as soon as I can. I will let the forum know what I find.

Bon

It's called a diversity antenna. The radio uses one or the other or both to get better reception. It's used in a lot of higher end cars to help with multipath distortion and signal fade specifically with FM radio.

RXGS

iTrader: (2)

I can see why you wouldn't want the antenna to extend, but i think it looks pretty cool, real old school, wish my es had one.On a sidenote, in our lx you can adjust the height of the antenna as you wish, can you not do this in the sc?

VVTiBob

Nope, it self adjusts to one of three height choices between 700~980mm depending on the frequency of the radio station selected. Thereby contributing to improved reception sensitivity by the length of the antenna deployed.

Harold57

Yes, that is correct, a diversity antenna. It is more common than you think. We had one in an '88 Mazda 929. Our Panasonic cordless phones that are 10 or 15 years old have them also and they weren't very expensive. The radio would be the interface, not Lexus.

huy33

Does it drive anyone else crazy when you're listening to the radio and the antenna goes down because a call comes and your phone is connected via bluetooth? This might fix that problem though.