[RFI] Honda RFI

Jimk8mr at aol.com Jimk8mr at aol.com
Thu Jan 17 21:33:25 EST 2008

A few more details, omitted for brevity in my first post:
While the noise is present everywhere, it is not truly broadband. Listening  
at HF with the IC-746, it is a series of broadband signals spaced every 20 
KHz,  with the noise falling off toward the edge to a fairly quiet KHz or two 
between  these signals.  On the IC-746 spectrum scope, it looks like a full wave  
rectified sine wave. Imbedded near the center of each band is a weak CW 
carrier,  very slightly unstable in frequency. 
On VHF with the AM detector in my FT-7800 it appears as a broadband  signal.
I made those observations a while back. Now that I can create the problem  
while parked (by moving the steering wheel), I can safely look further, though  
don't expect I could learn much more.
QSL on the use of braid for grounding. I am using #12 TW wire, with lots of  
Liquid Electrical Tape covering the connections. I've made a mental note to  
check them when snow and salt season is over.
73  -  Jim   K8MR
In a message dated 1/17/2008 6:22:00 P.M. Eastern Standard Time,  
dgsvetan at rockwellcollins.com writes:


If you contact someone at Honda with technical knowledge,  try to find out 
what motor type the EPS uses and how it is  controlled.  In short:  is the 
motor a permanent magnet DC type  with brushes, or is it operated as a 
servo motor?  Does the  controller use PWM or variable frequency to set 
motor speed and/or  torque?  Depending upon the answers to those questions, 
it may be  possible for you to determine a cure if they can't.

One other  comment:  If you used braid for the exhaust pipe grounding, keep 
an  eye on it periodically.  I found that tinned copper braid lasted about  
18 months before corroding away when placed under a vehicle and in contact  
with that hot pipe.  It was very effective until that  happened.

73, Dale

To  rfi at contesting.com, xxw0qe at comcast.net, mathenyr at marietta.edu,  
W8DRZ at aol.com, ac8e at zoominternet.net

[RFI] Honda  RFI

Last August I bought a new 2007 Honda  Fit.  While the ignition noise 
reasonable, especially  after adding a few easily done exhaust pipe 
there remained a  mysterious broadband noise noticeable on all bands at 
through 2  meters. It is worst on 15 meters where it was S9 on a HamStick. 
had  an odd pattern of being on most, but not all, of the time, and not 

Today I had the Eureka moment, and have determined it is  the Electric 
Steering (EPS). In particular, it begins  immediately upon any movement of 
steering wheel, and continues for  about 2 seconds after the last movement. 

Hence, no noise when  parked.  Driving down a straight road with hands off 
wheel,  it remains quiet until I move the wheel.

Do any Honda owners with  models equipped with EPS also experience this 
noise?  I am curious if  it is a problem extending beyond the Fit. A brief 
test in 
a new Accord  at the local dealer was inconclusive, in part because there 
a lot  of other RFI in the lot where we tested it. I plan to contact 
1-800 customer service number in a few days (the local service people, and  
regional customer relations person were very unhelpful once we  determined 
another Fit had the same problem). The problem in my  Fit is also 
in  the FM broadcast reception on weaker  stations, so it may be of 
interest (I 
hope)  to Honda on that  basis. 

Note that it requires an AM detector (or product detector)  to  observe 
noise.  A VHF FM radio is not likely to  hear it.

When the weather warms up I plan to remove the EPS fuse (a  50  amp, screw 
down type) for a some low speed experiments in an open  parking  lot. Would 

disabling the EPS likely be a safety issue,  at least for  open highway 

73    -   Jim     K8MR

**************Start the year off right.  Easy ways to stay in shape.     

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