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eHam Forums => Elmers => Topic started by: N4AHS on September 27, 2008, 06:12:47 AM



Title: Noise Problem in 08 Civic Hybrid
Post by: N4AHS on September 27, 2008, 06:12:47 AM
I have installed an Icom 208H in my 08 Civic Hybrid.  The radio is in the trunk with a mag mount antenna on the trunk lid.  The control head is located in front of the shift lever.  The power cable comes directly off the battery throught the firewall under the center console, under the backseat and into the truck.  With the engine running I have a nose level about S3 and increasing to S5 when breaking.  Any suggesting for reducing this noise will be greatly appreciated.  Thanks in advance for your help.  73


Title: Noise Problem in 08 Civic Hybrid
Post by: K0BG on September 27, 2008, 07:26:46 AM
There isn't much you'll be able to do. Hybrids, by their very nature are RF noisy. You can use split beads on some of the cables, which will reduce some of the RFI,  but not all of it by any means.

Go to my web site, and pull up the HyBrid article for more data.

Alan, KØBG
www.k0bg.com


Title: Noise Problem in 08 Civic Hybrid
Post by: KZ1X on September 27, 2008, 07:36:27 AM
I was waiting to hear about such a problem.  The PWM power controller in the regenerative braking system put out noise ...

So, you have to find out if the noise is radiated or conducted (or some of both).  If it's radiated noise, you may be able to do something about the antenna, such as mounting it properly.

Get a suitable battery (gel cell) and attempt to run the radio independent of the car's power supply.  if the noise is still there, it's radiated.

If it's coming in on the power wire it can easily be filtered.



Title: Noise Problem in 08 Civic Hybrid
Post by: K0BG on September 27, 2008, 10:28:42 AM
Steve....

John Pavelich, VE3XKD, has been doing extensive modifications to his Prius for the last couple of years. Although he has managed to reduce the level by nearly 20 dB, I don't believe it's low enough for SSB yet. And he's not the only one.

One very unfortunate aspect is the fact that vehicles are exempt from FCC Part 15. Even though Toyota has managed to quiet down the Prius and other Toyota Hybrids, the 2007 model my neighbor has is noisy enough that I can hear her nearly 2 blocks away on 20 meters. Twice that far on 80 meters.

My take is, it's the next BPL type problem!

Alan, KØBG
www.k0bg.com


Title: Noise Problem in 08 Civic Hybrid
Post by: KZ1X on September 27, 2008, 12:19:52 PM
Alan

I, too, am quite surprised/dismayed at this ... and this comment comes from someone who is involved professionally in EMI work, and also who sits on an ARRL committee for this topic.  On the other hand, it's not unexpected, says the cynic in me that wants to suppress such thoughts but has too many real-life experiences to be able to muster that energy.  I am generally in favor of minimum regulation of anything, but EMI rules are just like any other sort of pollution control.  In this century we simply live too close together to be able to ignore the effects of our junque on others.

The fellow with the Civic could help by reporting his findings from the experiment I suggested.  FWIW another local ham has a Civic Hybrid and reports no such problems, even with his use of a through-glass halfwave.  I think he's running a Kenwood D700.

I agree with your net synopsis that probably little can be done to help this fellow's situation, but I am wont to give it the old Yankee try first.  Plus we will all learn from the effort.

/steve


Title: Noise Problem in 08 Civic Hybrid
Post by: N4AHS on September 27, 2008, 04:21:49 PM
I connected an external power supply to the radio in the trunk.  It made no difference in the noise problem.


Title: Noise Problem in 08 Civic Hybrid
Post by: KZ1X on September 27, 2008, 07:25:54 PM
Then, it's as feared - the noise you're picking up is all radiated.

It's possible that changing the location of your antenna will help.  There's also the option that switching to a fixed-mount antenna would be helpful as well, but it's not a certainty.

Next on the list is to attack the noise source itself.   This can be quite complicated ... on an academic basis I'd like to see what it would take to do that, but we're talking about a real effort required from some talented people with pretty specialized skills and test gear.

Sorry to not be able to present a more positive outlook.


Title: Noise Problem in 08 Civic Hybrid
Post by: N6AJR on September 27, 2008, 09:39:06 PM
try running a ground to the shield side of the mag mount, perhaps it will help, mag mounts  have very little ground capability.


Title: Noise Problem in 08 Civic Hybrid
Post by: KB2CPW on September 27, 2008, 11:15:54 PM

  Forget it, I've owned a hybrid (Honda) since early 2002 and the computers,cops,modules howl endlessly and bury the rx on hf with 40 over noise levels. Sounds like a Husky chainsaw is running on my front seat when I have HF on..

  You can forget HF in these cars unless you wrap the engine compartment and trunk area in 4 miles aluminum foil and copper strapping.

  It looks like VHF/UHF is now your bag.. Gimmee a call on 52!!


Title: Noise Problem in 08 Civic Hybrid
Post by: KB2CPW on September 27, 2008, 11:18:57 PM

  Oops, read this further.. Sorry

  I am running an FT857 in mine, no problem on VHF UHF at all.. Try a different rig..

  My HF problem is unsolvable. Yes you can knock it down with some work, but its a losing battle to get it down enough to work anything s6 or under..


Title: Noise Problem in 08 Civic Hybrid
Post by: N4AHS on September 28, 2008, 05:20:05 AM
Well it looks like I will be giving up the good gas mileage. I think there are some good deal out there now on a gas hog SUV.  :)


Title: Noise Problem in 08 Civic Hybrid
Post by: WA3SKN on September 29, 2008, 11:47:13 AM
If you are thinking about "test driving" any new vehicles, take a portable radio along with you for testing this type of problem!
And always check whether any other eqpt is a type "A" or "B" approved Part 15 device... it makes a difference!
73s.

-Mike.