Because you should just cut your own! Pair of Side cutters (dikes, diagonals)
And dab some black paint on top when finished. And bam! Saved $25 plus shipping. Unless you wanted the 2" antenna...

 

How's the reception?

 

+1 ^^^

 

I always wanted to do that, but then I wouldn't have a mast for my Union Jack flag.

 

Reception is same. So hop to it!

 

Boing...boing...
I just cut my wifes antenna on her VW. I wana see wha she says. If its a bust I will give her mine cuz I already have a 3" aluminum one.

 

Lmao. Weight reduction

 

Yeah i would doubt reception would be any different than getting an alta stubby or something along those lines being the alta one is short and doesnt in anyway boost signal. So if their stubbys work this should too.

I personally love my stubby. I believe its an 1" long. Changes the way i look at my car for sure.

 

This would not interfere with SAT reception correct?

 

In theory an antenna is designed to be optimal for the intended reception frequency.
For FM (88Mhz) the optimal (full wave) vertical type antenna would be over 10' tall (120.65625"). Not very practical....... But multiples of the full wave length work well such as 1/2 wave or 1/4 wave etc.
The typical antenna on a car is the 1/4 wave size or about 32".
The OEM roof antenna on my Clubman is about 16" or 1/8 wave.

So cutting the original antenna to an arbitrary length may not yield the best reception but will probably work OK in most metro areas that don't have allot of tall buildings etc. (An antenna a little too long is as bad as too short - between the wave multiples).

Some antenna designs have a coil of wire or other components built in to make the antenna longer in an electrical sense. Probably what is done in the shorty aftermarket antennas?

On my Clubman there is a 2nd antenna etched into the rear side window on the drivers side. When I take the roof antenna completely off the FM still works pretty well but the AM doesn't work very well at all.

 

I removed my antenna and I still get good FM reception, even from Port Angeles (I'm in Victoria, Canada.)

The one AM station I tune into in town comes in clear as well.

 

While you are correct about the wave length, you forgot that the wire that makes up the antenna is wound. It might very well be 1/2 or full wave.