RadioBanter - View Single Post - Need help: Radio in Car .. couple of problems

March 28th 04, 03:39 PM

On 28 Mar 2004 06:01:58 -0800, (D.) wrote:

Hi,
I am beginner .. sorry if some of this seems like stupid question(s):

I have installed a ICom F2010(2020) into my Jeep.
The radio unit itself is installed in the back where the CD changer
was, the antenna cable is a bit too long, so it is stored in a loop.
Control unit is seperated with 8 meter cable from main unit and is
mounted underneath the ashtray (so basically it is sitting above the
gear box).

The antenna is mounted on the roof the car:
A GME 409L (ground independend), mounted on a spring S004

Frequencies used are in the 460Mhz-490Mhz range.

The problems I am experiencing now:
- Whenever the unit is Rx ... I can hear a whisling sound, which is
only audible if I accelerate (there seems to be a relationship to the
RPMs ?)
- If the car is stationary I can Rx ok, once the car is moving (maybe
50 kmh) the Rx is braking up

Is above normal, if not .. any ideas how to fix it ?

I am aware that I should shorten the antenna cable, rather than
looping it.
Could the transmition be causing the whisling noises ?
Is the antenna I am using a piece of s(*^&(^ and should I use a
different one ?
Thanks, D.

Sounds a lot like 'alternator whine'. Is your radio hooked directly
to the battery, if not then proceed to make it so (and fuse both
positive and negative leads). If that does nothing, or not enough, to
fix the problem you may wish to consider a DC noise filter. RatShack
carries a couple of them, the 10 amp model is about $16 (pn 270-051).