On Mon, 27 Mar 2006 11:41:49 +0100, Paul Morgan
wrote:

I am planning on installing my JVC DAB add-on box in my "new" runaround
car (98 Omega). It has an integrated FM aerial in the rear screen, so no
go with that one for DAB. However it also has a small stubby aerial
body-mounted at the rear of the roof. This, I believe, is for the
integrated car phone kit (which I never intend to use, it relies on the
factory head unit which has been removed).

So I'm thinking of removing this aerial and using the resulting hole in
the roof to mount a DAB aerial. I know I can buy a proper DAB body-mount
aerial, but after seeing the price of them I'm sensing the marketing
machines in overdrive... £40 for what is basically a piece of metal and
some coax cable. Of course it's digital, which justifies the price
entirely as radio waves carrying digital signals are far more fussy than
their analogue counterparts at the same frequency ;-)

I noticed there seems to be very little difference in length of commonly
available roof-mount bee sting FM aerials compared to the DAB aerials.
And unsurprisingly the price is cheaper by a factor of ten! £3 + post,
for example this one: http://tinyurl.com/ln9pm

Obviously I'll need to change the connector to an SMB (but it seems
there are two types of connector common on DAB aerials so I might have
to do that anyway even with a £40 DAB aerial). Are there any other
reasons this aerial won't work well for DAB? It certainly seems like it
should work fine at DAB frequency of ~225MHz and the lack of an
amplifier means that there's no filtering specific to FM frequencies.

Thoughts? Yes I know it's only £40 but why pay such a ridiculous mark-up
if a £3 item will do a similar job?

Cheers
Paul.

It's not just the frequency that's different. I get the impression
that the field-strength is a lot weaker for DAB too, so you do need a
high quality aerial to make sure you're not wasting any precious dBs
on a crummy downlead or whatever.

You can get splitters that attempt to give you a DAB signal from an FM
aerial, but others have said the performance is crap.

I've got a Pioneer, amplified roof-mount DAB aerial on my car and I
get two muxes reliably in Milton-Keynes. I'm not sure if that's good
or not...

Cheers,

Colin.