Radio reception terrible

[usedcyclesales]

I've owned 5 ventures and never had bad radio reception(FM) but I have it BAD now just goes in and out. Where do I begin to trouble shoot this ? connection at antenna is good no rust , corrosion etc... and tape deck plays fine over bumps etc.. just radio goes in and out

[csdexter]

Check antenna cable throughout (connection at antenna pole is okay, you say -- check that the connection in front, at the radio, is also ok). Also check the cable isn't shorting to ground anywhere.

 

Does the radio fade in and out with the motorcycle stationary or moving? If when moving, it's the antenna wire (broken or shorting). If when standing still, there's a problem elsewhere like bad grounding for the radio.

[Condor]

I've owned 5 ventures and never had bad radio reception(FM) but I have it BAD now just goes in and out. Where do I begin to trouble shoot this ? connection at antenna is good no rust , corrosion etc... and tape deck plays fine over bumps etc.. just radio goes in and out

 

You just might have a bad connection to one of your speakers???

[Monty]

I had to open all my radio connectors, spray them down with contact cleaner, then added dielectric grease. All good now.

[Karaboo]

Also, make sure the Local/Distant switch is set to DX (distant). Makes a difference.

[MidlifeVenture]

There was a post where antenas were hooked backwards CB to radio and radio to cb I know I read it here then checked mine

[MikeWa]

On most radios the AM uses the mast antenna. FM generally uses a wound coil antenna inside the radio. So I agree it is most likely a poor connection somewhere. Clean and grease the plugs and contacts.

 

Mike

[LilBeaver]

On most radios the AM uses the mast antenna. FM generally uses a wound coil antenna inside the radio. So I agree it is most likely a poor connection somewhere. Clean and grease the plugs and contacts.

 

Mike

 

This information is backwards.

 

The wavelength of an FM wave (in the middle of the FM band) is on the order of 10 feet -- so an optimal FM antenna will be an integer multiple of quarter of the wavelength in order to induce the most electrical signal in the metal rod (dipole antenna via resonance). So a quarter-wave length antennas are used which puts the length right around 2.5 feet. (note there are plenty of ways around having a straight antenna -- for example some do use a coil near the bottom of the antenna to add some "length" to the rod without actually extending the antenna height itself)

 

The average wavelength for the AM band is nearly two orders of magnitude larger at ~980 ft (for 1000 kHz). Obviously a dipole antenna is COMPLETELY impractical for the dipole (straight rod) arrangement and therefore a coil antenna is used and generates the current in the antenna by inducing the current in a loop of wire instead of inducing resonances in a rod.

 

Note the following:

Frequency and wavelength are related by the speed in which they travel. For radio waves (EM radiation), they travel at the speed of light. So with 'air' as the medium (electrical permittivity of air ~1) we have the following:

speed of wave=wavelength x frequency

Speed of light = wavelength x frequency

--> wavelength = C/frequency

 

Furthermore:

AM frequency is ~600 to 1600 kHz (0.6 MHz to 1.6 MHz) and FM is ~88 to 108 MHz

Speed of light in 'air' is 2.99 x 10^8 m/s (9.81 x 10^8 ft/sec)

 

AM Wavelength at 1.0 MHz is: (2.99x10^8 [m/s])/(1.0x10^6 [s^(-1)])= 299 [m] ~ 980 [ft]

FM Wavelength at 98 MHz is: (2.99x10^8 [m/s])/(98x10^6 [s^(-1)])= 3.1 [m] ~ 10.0 [ft]

[LilBeaver]

I've owned 5 ventures and never had bad radio reception(FM) but I have it BAD now just goes in and out. Where do I begin to trouble shoot this ? connection at antenna is good no rust , corrosion etc... and tape deck plays fine over bumps etc.. just radio goes in and out

 

Check antenna cable throughout (connection at antenna pole is okay, you say -- check that the connection in front, at the radio, is also ok). Also check the cable isn't shorting to ground anywhere.

 

Does the radio fade in and out with the motorcycle stationary or moving? If when moving, it's the antenna wire (broken or shorting). If when standing still, there's a problem elsewhere like bad grounding for the radio.

 

As all have recommended, checking the connections is improtant.

In addition to "csdexter" question - when it fades in and out does it do it on ALL of the stations or just one. Is it ONLY FM or is it AM as well?

 

Note there is a connection under the passenger seat for the FM antenna to the main radio amp.

[dacheedah]

I would check to see if the cb was on first, try turning that off

 

Not sure what bike you are talking, on first gen the antennas go through a am/fm cb combiner on second gen your cb should be on the left ( It has the tuning coil ). If you are on a first gen try bypassing the combiner ( Do not key up your cb while antenna disconnected).

[MikeWa]

This information is backwards.

 

The wavelength of an FM wave (in the middle of the FM band) is on the order of 10 feet -- so an optimal FM antenna will be an integer multiple of quarter of the wavelength in order to induce the most electrical signal in the metal rod (dipole antenna via resonance). So a quarter-wave length antennas are used which puts the length right around 2.5 feet. (note there are plenty of ways around having a straight antenna -- for example some do use a coil near the bottom of the antenna to add some "length" to the rod without actually extending the antenna height itself)

 

The average wavelength for the AM band is nearly two orders of magnitude larger at ~980 ft (for 1000 kHz). Obviously a dipole antenna is COMPLETELY impractical for the dipole (straight rod) arrangement and therefore a coil antenna is used and generates the current in the antenna by inducing the current in a loop of wire instead of inducing resonances in a rod.

 

Note the following:

Frequency and wavelength are related by the speed in which they travel. For radio waves (EM radiation), they travel at the speed of light. So with 'air' as the medium (electrical permittivity of air ~1) we have the following:

speed of wave=wavelength x frequency

Speed of light = wavelength x frequency

--> wavelength = C/frequency

 

Furthermore:

AM frequency is ~600 to 1600 kHz (0.6 MHz to 1.6 MHz) and FM is ~88 to 108 MHz

Speed of light in 'air' is 2.99 x 10^8 m/s (9.81 x 10^8 ft/sec)

 

AM Wavelength at 1.0 MHz is: (2.99x10^8 [m/s])/(1.0x10^6 [s^(-1)])= 299 [m] ~ 980 [ft]

FM Wavelength at 98 MHz is: (2.99x10^8 [m/s])/(98x10^6 [s^(-1)])= 3.1 [m] ~ 10.0 [ft]

 

 

No it's not backward.

 

For those who want to know. Go out and take the antenna off your car and see what still works on the radio.

Edited May 17, 2013 by MikeWa

[timgray]

No it's not backward.

 

For those who want to know. Go out and take the antenna off your car and see what still works on the radio.

 

I have done that. Both AM and FM stops working, except for the single FM station that is 12 blocks away. Both bands use the antenna. IF the coil in the radio was the only one used, then nothing will work as the whole radio case is metal. The "COIL" in there is to do a matching for AM to the short FM antenna whip that is on the car.

 

Disclaimer: I have an Electronics Engineering Degree and a Ham Radio Operator that has built radios and antennas.