[Antennas] Engine Noise on HF Radio

[Ray Brown]

----- Original Message ----- 
From: "Art Barbetta Jr N8RKA" <n8rka at n8rka.us>


>I have a Tarhill II screwdriver antenna on my 2008 Focus.
> When I put my FT-857 in my car I get a whining noise that increases when 
> you accelerate the noise get faster.
>  What can be done to get rid of the noise..

  Well, you have classic alternator whine. One of the causes of the whine
could be that one of the 6 diodes in the alternator is either blown open,
or more likely blown shorted. The rest of the alternator can still keep the
battery charged but the one winding would make a classic half-wave
ripple that the battery is trying to dampen but can't completely cover it up.

  Another possible cause could be that the battery is getting weak and
it's not smoothing out the output from the alternator. That would be easy
enough to check out, if your battery is between 2 to 3 years old, it may
be in your best interest to replace it and see if that clears your whine up.
Otherwise, you may have to test the alternator and see if it can produce
the full output it's rated for. If it only puts out 2/3 of rated output, that would
confirm the blown/shorted diode and a new alternator is in order.

  Good luck!

                        Ray, KB0STN