Topic

But this aerial is shorter than the standard aerial - 60cm. Have you tried this aerial? I have bought one and the reception is worse!!

If I remember right from my teenage years and cb and HAM radio, the aerial length is tuned to the wavelength of the signal to be received by its actual length (that's why its called wavelength). For correct FM reception the aerial need to be the correct length for the ideal reception, also the aerial is tuned to the body of the car or ground as it also makes a difference. For perfect or as good as it gets reception, the aerial for the MGTF will be sized correctly by the OEM. If you fit a shorter or longer aerial, then you will get worse reception in shadowy or fringe reception areas.
For the best signal, simply fit an aerial of original size and make sure it is properly grounded to the car body!

Frequency is the pulsed scramble of the signal that allows many stations to be transmitted on a particular wavelength and what allows your radio to lock onto separate stations on the band. Remember the old science lessons at school with a long slinky! Wave it from side to side gives you an oscillation or wavelength, push it in and out gives you frequency.

Sundance

What is the original aerial length??
Agree with you Sundance
I've got 3 tf on the drive all with diferent aerials, so in the interest of "scientific" research have had a play this morning.
Stayed with tf115 fitted with a new Pioneer head unit and fitted the aerial described above, tuned to a weak frequency around mid-band. I could just just hear music.
Changed to a base loaded rubber type, same length similar to that fitted to hatchbacks. Slight improvement.
Then changed to a 77cm fibreglass whip. I've no idea where it came from and I'm fairly sure it isn't OEM. Brilliant is the best description.
Unfortunately the aerial that I believe is OEM has a snapped thread, it is 60cm long but can't be tested.
Dare I say SIZE matters