Need help: Radio in Car .. couple of problems
 

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.

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).

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).

In article ,
says...

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

The only "stupid" question is the one you never ask.

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

Since the 2010/2020 series are FCC Part 90 type accepted, this is
a good match.

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 ?)

Alternator whine. Very common. You need to check that all your
radio and antenna ground connections are clean and solid, that the body
of the car is well-bonded (electrically speaking) to the engine block,
and hence to the negative battery termimal, AND you should purchase and
install an alternator whine filter.

- If the car is stationary I can Rx ok, once the car is moving (maybe
50 kmh) the Rx is braking up

That's "breaking," BTW. Possible antenna problems. You should
check the forward and reflected power with a good-quality thruline RF
wattmeter, such as a Bird 43 series or a Telewave.

Also, the antenna's outer shell conductor may not be well grounded
to the frame of the vehicle.

If any or all of the above sounds unfamiliar or overly complex, I
would strongly recommend that you seek professional assistance from
whatever amateur radio club or two-way radio shop is local to your area.
You cannot properly troubleshoot things like antenna problems without
the proper test equipment.

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.

Antenna cables should be cut to length unless the manufacturer of
the antenna explicitly states otherwise in their printed instructions
(which should have been included with the antenna).

Could the transmition be causing the whisling noises ?

No. That's "transmission," BTW.

Is the antenna I am using a piece of s(*^&(^ and should I use a
different one ?

No idea. Antennas are pretty simple devices. If the one you have
is built for the frequency range you're using, I don't see why it would
not work if it was properly installed.


--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute.
(Known to some as Bruce Lane, ARS KC7GR,
kyrrin (a/t) bluefeathertech[d=o=t]calm -- www.bluefeathertech.com
"If Salvador Dali had owned a computer, would it have been equipped
with surreal ports?"

In article ,
says...

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

The only "stupid" question is the one you never ask.

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

Since the 2010/2020 series are FCC Part 90 type accepted, this is
a good match.

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 ?)

Alternator whine. Very common. You need to check that all your
radio and antenna ground connections are clean and solid, that the body
of the car is well-bonded (electrically speaking) to the engine block,
and hence to the negative battery termimal, AND you should purchase and
install an alternator whine filter.

- If the car is stationary I can Rx ok, once the car is moving (maybe
50 kmh) the Rx is braking up

That's "breaking," BTW. Possible antenna problems. You should
check the forward and reflected power with a good-quality thruline RF
wattmeter, such as a Bird 43 series or a Telewave.

Also, the antenna's outer shell conductor may not be well grounded
to the frame of the vehicle.

If any or all of the above sounds unfamiliar or overly complex, I
would strongly recommend that you seek professional assistance from
whatever amateur radio club or two-way radio shop is local to your area.
You cannot properly troubleshoot things like antenna problems without
the proper test equipment.

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.

Antenna cables should be cut to length unless the manufacturer of
the antenna explicitly states otherwise in their printed instructions
(which should have been included with the antenna).

Could the transmition be causing the whisling noises ?

No. That's "transmission," BTW.

Is the antenna I am using a piece of s(*^&(^ and should I use a
different one ?

No idea. Antennas are pretty simple devices. If the one you have
is built for the frequency range you're using, I don't see why it would
not work if it was properly installed.


--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute.
(Known to some as Bruce Lane, ARS KC7GR,
kyrrin (a/t) bluefeathertech[d=o=t]calm -- www.bluefeathertech.com
"If Salvador Dali had owned a computer, would it have been equipped
with surreal ports?"

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

D-

My guess is that the whistle is alternator whine, as others have suggested. If
so, it is probably not coming in through the antenna, but through the power
connection to the audio amplifier.

I would suggest using a pair of 10 AWG wires directly from the battery
terminals to the main unit (Fused, of course). Either alternator or ignition
noise might be coupled through the control unit's ground, so try isolating it.
Let it obtain audio, power and ground through the 8 meter cable.

If the antenna is ground independent, make sure you didn't ground it by
accident. There could be noise conducted through its shield back to the radio.

73, Fred, K4DII

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

D-

My guess is that the whistle is alternator whine, as others have suggested. If
so, it is probably not coming in through the antenna, but through the power
connection to the audio amplifier.

I would suggest using a pair of 10 AWG wires directly from the battery
terminals to the main unit (Fused, of course). Either alternator or ignition
noise might be coupled through the control unit's ground, so try isolating it.
Let it obtain audio, power and ground through the 8 meter cable.

If the antenna is ground independent, make sure you didn't ground it by
accident. There could be noise conducted through its shield back to the radio.

73, Fred, K4DII