Vectra radio crackles on Medium & Long Wave

My Vectra's radio crackles on long and medium wave, but perfect reception on FM.
There was a previous discussion and I tried the link, but too late the previous post has been removed.
Please would someone restate what the cure might be?
Thanks.
twhite

 

Check the aerial co ax connection at the aerial base - you need to lower the head lining slightly.
The wire is normally wrapped in foam - just pull it off.

 

Thanks. I tried "lowering the headlining a bit" but found it impossible to get sight of the coax connection at the aerial base. There is an inner skin of metal with three holes cut in it, and seems impossible to get sight of or to work on the aerial base without taking the headlining right out; and the Hayes manual says all the other trim needs to come out first. Is this right or does anyone know if there is some trick to it please?
TIA,
twhite
Check the aerial co ax connection at the aerial base - you need to lower the head lining slightly.
The wire is normally wrapped in foam - just pull it off.

 

trust me - it can be done. The connection is only about 4inches from the aerial base. You can just pull enough loom out to get it. You need to peel the foam off.