Radiated RFI on 2M in YJ, experience? - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > General Jeep Discussions > Communications and Electronics

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 10-12-2012, 07:12 PM   #1
Jeeper
 
BlueRidgeYJ's Avatar
 
Join Date: Mar 2012
Posts: 4,917
So I recently moved my 2m antenna to the front bumper, and am picking up tons of radiated noise with the engine off, ignition on. Any body solved this one already?

__________________
“Coming of age in a fascist police state will not be a barrel of fun for anybody, much less for people like me, who are not inclined to suffer Nazis gladly and feel only contempt for the cowardly flag-suckers who would gladly give up their outdated freedom to live for the mess of pottage they have been conned into believing will be freedom from fear.”
BlueRidgeYJ is offline   Quote Quick Reply
Old 10-13-2012, 08:47 AM   #2
Jeeper
 
sparky's Avatar
 
Join Date: Oct 2009
Location: Phila
Posts: 1,798
Where was it before, and did you have any problems when is was in that location.

There should be a grounding strap between the hood and firewall. Make sure it's there.

sparky is offline   Quote Quick Reply
Old 10-13-2012, 09:31 AM   #3
Jeeper
 
BlueRidgeYJ's Avatar
 
Join Date: Mar 2012
Posts: 4,917
I'll slap one on there and see how that does.

It's a comet NMO on a diamond 400 mount, I had it on the tailgate and was getting clean reception but not the range I was after. I moved it to the pass side, front bumper. It wasn't grounding great, so I ran a strap from the bumper to batt ground to ensure good current, that eliminated a little noise. But the primary source is still there, and it has my squelch gate at about 45% with the ignition on. Just thought I'd get a few ideas before I started searching for it today.

Thanks Sparky.

Oh, and key off, or just radio on, or lights on make no difference. Its all in the ignition, and a touch of alternator whine when running. With all off it recieves great. I'm a bit confused I guess on what componant is radiating noise without the engine on.
__________________
“Coming of age in a fascist police state will not be a barrel of fun for anybody, much less for people like me, who are not inclined to suffer Nazis gladly and feel only contempt for the cowardly flag-suckers who would gladly give up their outdated freedom to live for the mess of pottage they have been conned into believing will be freedom from fear.”
BlueRidgeYJ is offline   Quote Quick Reply
Old 10-15-2012, 09:46 AM   #4
Jeeper
 
sparky's Avatar
 
Join Date: Oct 2009
Location: Phila
Posts: 1,798
Now we have a head scratcher. If I read you correctly, RF noise with everything shut down.

Can you try a different power source instead of the battery. Is it coming from the house? (Still there if you park someplace else.)

Dont' forget the classic Jeep grill, with those big vertical holes, letting air in and RF out.

I'm just spitballing on these.
sparky is offline   Quote Quick Reply
Old 10-15-2012, 11:08 AM   #5
Jeeper
 
BlueRidgeYJ's Avatar
 
Join Date: Mar 2012
Posts: 4,917
Quote:
Originally Posted by sparky
Now we have a head scratcher. If I read you correctly, RF noise with everything shut down.
No. Getting RF with ign switch on, engine off.

I have eliminated power feed noise. I have eliminated outside world sources. There is somehing that is txing in the electric system, but it isnt the spark gap transmitter that makes horsepower. It isnt effected by the lights or radio circuits, and leaves about 10 sec after turning the key to off. Something in the firing system? Computer based? RF from ground path somehow?
__________________
“Coming of age in a fascist police state will not be a barrel of fun for anybody, much less for people like me, who are not inclined to suffer Nazis gladly and feel only contempt for the cowardly flag-suckers who would gladly give up their outdated freedom to live for the mess of pottage they have been conned into believing will be freedom from fear.”
BlueRidgeYJ is offline   Quote Quick Reply
Old 10-15-2012, 11:13 AM   #6
Sponsoring Vendor
 
Ibuildembig's Avatar
 
Join Date: Aug 2010
Location: Fruitland, Missouri
Posts: 8,338
Fuel pump....also, the woven ground straps are the cause of most noise. I would use a stranded/coated copper lead instead. The R56 grounding manual outlines why the straps are not to be used. Hope this helps
Ibuildembig is offline   Quote Quick Reply
Old 10-15-2012, 03:22 PM   #7
Jeeper
 
BlueRidgeYJ's Avatar
 
Join Date: Mar 2012
Posts: 4,917
Quote:
Originally Posted by Ibuildembig
Fuel pump....also, the woven ground straps are the cause of most noise. I would use a stranded/coated copper lead instead. The R56 grounding manual outlines why the straps are not to be used. Hope this helps
10-4 on the straps.

Wouldnt the FP stop radiating, or at least change in modulation, once pressure is reached? If I leave the key on, it just keeps going and going.
__________________
“Coming of age in a fascist police state will not be a barrel of fun for anybody, much less for people like me, who are not inclined to suffer Nazis gladly and feel only contempt for the cowardly flag-suckers who would gladly give up their outdated freedom to live for the mess of pottage they have been conned into believing will be freedom from fear.”
BlueRidgeYJ is offline   Quote Quick Reply
Old 10-15-2012, 03:26 PM   #8
Sponsoring Vendor
 
Ibuildembig's Avatar
 
Join Date: Aug 2010
Location: Fruitland, Missouri
Posts: 8,338
In theory yes....It will run for a few seconds on initial key-on. But if its not started, it will pulse and keep the pressure on the rail. I have seen some that run continuous, but they are not nearly as common. I read a thread somewhere a year or so ago that a guy had a similar problem but I think his was when he keyed up it got into the FP and shut it down. I will try to find it.
Ibuildembig is offline   Quote Quick Reply
Old 10-15-2012, 03:45 PM   #9
Jeeper
 
BlueRidgeYJ's Avatar
 
Join Date: Mar 2012
Posts: 4,917
Thanks, that gives me a point of assault. I was under the assumption it would cut out after a few seconds. Good to know.

I'll disable the pump and see what that does.
__________________
“Coming of age in a fascist police state will not be a barrel of fun for anybody, much less for people like me, who are not inclined to suffer Nazis gladly and feel only contempt for the cowardly flag-suckers who would gladly give up their outdated freedom to live for the mess of pottage they have been conned into believing will be freedom from fear.”
BlueRidgeYJ is offline   Quote Quick Reply
Old 10-15-2012, 07:16 PM   #10
Jeeper
 
BlueRidgeYJ's Avatar
 
Join Date: Mar 2012
Posts: 4,917
OK, I pulled the FP relay - no change, put it back. So I pulled the "fuel sys ecu" fuse - noise gone. So, what's that mean?

__________________
“Coming of age in a fascist police state will not be a barrel of fun for anybody, much less for people like me, who are not inclined to suffer Nazis gladly and feel only contempt for the cowardly flag-suckers who would gladly give up their outdated freedom to live for the mess of pottage they have been conned into believing will be freedom from fear.”
BlueRidgeYJ is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 05:18 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC