PaulG1975 said:
I have a 2008 Swift Charisma 230 fitted with a CD/radio. I would like to change it for a DAB one. My question is, will it work with the existing aerial on the side of the van, or would I have to replace that too.
Well for once I am going to have a major disagreement with the Prof.
Single whip aerials for receive only don't need to be matched - they will just work. Think of the telescopic aerial on a portable radio - it can be any length from about 6in to over 2ft but it will work albeit the longer aerial will be better at getting weaker signals. The problem here is that if the radio aerial on the caravan is one of the small telescopic types (often branded Ring) then it probably has an amplifier in the base which will likely not pass the DAB frequencies.
Having said that most car radios with DAB have a separate antenna connector for DAB which will provide voltage to drive the amplifier found in most car DAB aerials. If your caravan has a TV aerial it will pass and amplify DAB frequencies so you could use the radio aerial to feed the AM/FM aerial connector and the TV aerial to feed the DAB. Pictures I have seen suggest that the SC230 is fitted with a Vision Plus 300 series aerial - i.e. the flying saucer - and if so that should work perfectly as it is omnidirectional and dual polarity.
If however you have a 500 series directional aerial you may have problems as (1) TV and DAB may not be transmitted from the same local transmitter site and (2) DAB is vertically polarised which may mean a poor signal if your TV signal needs the aerial to be horizontal.
One other possibility is to get an on-glass tape DAB antenna and stick it to a window near the radio that you don't usually open. These two items on eBay may do the job: 361357013046 or 361200278754. I had one of the latter type on my last car and it worked very well. They can be mounted either way up but must be vertical