On Sat, 29 Sep 2007 10:01:50 +0100, the renowned "Dave Plowman (News)"
wrote:

In article ,
Bill Freeman wrote:
The roof antenna lead is the one with the
capacitor.

Anyone know what the purpose of an inline capacitor would be on a car
radio?

At the frequencies used for AM reception lead capacitance is critical.
Older radios used to have a trimmer to get an exact match- newer ones do
this automatically. So all aerials should have approx the same
capacitance. If you have a longer than usual lead - for a rear mount etc -
the cable capacitance goes up, so you add a series one to bring it back to
that standard. Same as an extension lead will have.

0.85uF? It would have an impedance of about 1/3 ohm at 540kHz--
essentially a short circuit.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
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