[TVI-RFI-EMI] Ford fuel pump Interference

[Greg Taylor]

Hello Group,

I just subscribed to this reflector and I am hoping to find an answer to my
problem.  I have a 1995 Ford Bronco. I have a couple of rigs in my Bronco, a
Kenwood TM-733 for VHF & a Kenwood TS-50 for HF with the AT-50 in line back
about 18 inches from a
High Sierra 1500 Screwdriver antenna.  Also inline I have a Palstar mobile
Watt/SWR meter. My problem is that while the Bronco is running I have as
much as an S-7 noise level. Noise Blanker takes out most all the other noise
if any is there. I have done some tests and have found what I believe is RF
noise generated by the fuel pump. I have the power leads for the rigs
running directly to the battery with a 50 amp breaker out by the battery
plus the original fusing in the power lines of the rigs.  When I turn the
key to the ACC. position the S meter just sits on the left hand peg or
maybe a little reading. When I turn the ignition switch on and you hear the
fuel pump come on there is the noise at about S-7.  This is only until the
fuel pressure reaches the operating level and then the noise is gone.  After
the
engine is running the noise is there all the time.  This makes it difficult
to hear signals lower than an S-7.  I can take the coax off the rig and the
noise is gone. I am quite confident this noise is RF being generated by the
fuel pump and the antenna or the coax is picking it up.  Well there you have
it. Has anyone seen this sort of problem before and does anyone have a cure.
I am open to suggestions and would like to try to get this problem fixed if
possible.

73

N9OUK Greg

n9ouk@arrl.net
http://my.hsonline.net/~gtaylor/index-2.htm

"The only thing necessary for the triumph of evil is for good men to do
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Edmund Burke (1729-1797)