Radio signal noise question

[Barney Eaton]

I repaired a antenna for a mid '60's Buick and the owner says there is noise (coming out of the radio) when the antenna goes up or down. 

There are no filters on the antenna......so what would cause the noise and are there filters in the radio to suppress that?

Do you think the noise is from the antenna sections moving or would it be noise from the antenna motor that is getting to the radio electronics?

 

[DS_Porter 89 Burgandy]

Before I swapped out my radio for a reconditioned unit with new capacitors I could "hear" all the static sources in the car and they were mostly from

motors  The brushes in DC motors arc slightly and this static is throughout the plus side of the 12v supply. Radios need good filter caps to smooth and remove it so that it doesn't pass through the radio amp and out through the speakers.

 

So yes I believe it is the antenna motor. A capacitor can be placed across the motor connection to reduce the noise. Trial and error to determine the value of the capacitor.  A sharper tech than I might know what value works best..... 

[Y-JobFan]

I have had several cars over the years that even when newer you could hear them going up and down through the radio

 

[dship]

1 hour ago, Y-JobFan said:

I have had several cars over the years that even when newer you could hear them going up and down through the radio

 

Same here for me.  But once the antenna is in position (either up or down) noise stops....no big deal in my experience.

[D-a-n-i-e-l]

Bad ground