External FM radio antenna?

[tonybelding]

This might seem to some like a dumb topic. . . (FM radio? What's that, something from the last century? Har har!) But yeah, my FM reception is horrible, and I was wondering if anybody has tried putting a better antenna on their car. And I do mean without drilling holes in body panels or just sticking it on with a big gob of J-B Weld!

 

[X.l.r.8]

I assumed that’s why the originals came with Sirus. I just stream the radio via my phone and I’ve given up trying to find a station.

 

[JohnGarziglia]

This might seem to some like a dumb topic. . . (FM radio? What's that, something from the last century? Har har!) But yeah, my FM reception is horrible, and I was wondering if anybody has tried putting a better antenna on their car. And I do mean without drilling holes in body panels or just sticking it on with a big gob of J-B Weld!

When I first got my Roadster in 2011, I noted the same thing about FM (and AM) radio reception. I tried quite a variety of things including temporarily attaching a whip antenna to see if that improved reception and putting in copper foil to shield the PEM.

The bottom line is that nothing related to the antenna made a difference. The antenna wire that goes up around the RH side of the windshield with an in-line antenna amplifier is just as effective as anything else I tried. I think that the poor FM reception is not due to the antenna but rather to the spurious electrical noise created by the car's various electrical components. That spurious electrical noise affects AM reception with noise that can be heard -- the same noise likewise affects FM reception, not with noise, but with a reduced signal level/reception range for FM stations.

A knowledgeable RF engineer could probably put noise filters and chokes on the car's motor and other offending components. That is what other car manufacturers have done for years with things like resistor spark plugs and such. But, such noise filters and chokes will have an effect upon the efficiency of the filtered or choked component to the end that in the Roadster there would likely be more battery use, fewer miles per charge, and slower acceleration, also things that are negatives.

You might try swapping out the head unit for a different brand. I found that the originally installed Alpine unit with multiple outboard modules was more impacted with poor AM and FM reception than the Kenwood unit that I subsequently installed. I posted something on this forum about radio swap and the reasons for it several years back.

 

[tonybelding]

I think that the poor FM reception is not due to the antenna but rather to the spurious electrical noise created by the car's various electrical components. That spurious electrical noise affects AM reception with noise that can be heard -- the same noise likewise affects FM reception, not with noise, but with a reduced signal level/reception range for FM stations.

That is disappointing, but it does make sense. I have also noticed the AM noise you describe. (It makes my Roadster sound like a Formula E car when I accelerate. Zzzzzz-ZZZZZ!)