| Author |
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Red Bird
| | Posted on Tuesday, March 25, 2003 - 6:52 pm: | 
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Hello guys (and gals if there are any on here!!)
I have a mobile problem. I have a whine in the radio front end(NB ANL are ineffective on the noise) and i belive it is caused by the alternator . The noise is only evident when i connect the antenna to the radio so I think the noise is coming in through the antenna and not the power cord. Ok heres my setup and how i have it mounted. I have a cobra 29 LTD classic (old style pre 1997) mounted under my dash in my 1994 Pontiac sunbird. I run the radio on a wilson 1000 magna mount mounted on the trunk with new RG mini 8 coax. I have the radios positive power wire run diretly to the positive on the battery and the negative to the seatbolt on the pass side. I also have a alt filter capacitor mounted on the alt and the alternator is fairly new as i had it installed new when i got the car used a few years ago. I also have the trunk grounded to the chassis with a ground strap so i guess i have all bases covered! Could the Wilson 1000 being a magna mount be the cause? Would hooking up the negative wire to the battery help out? As a last resort im thinking of getting a trunk lip mount and a wilson silverload and see if that takes care of the problems....... I hope some of you guys can give me some ideas and thoughts on the interference problems.. |
KGC755
| | Posted on Tuesday, March 25, 2003 - 10:59 pm: |
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Turn off the engine and see if the whine is still present. Maybe the fuel pump... |
de
| | Posted on Wednesday, March 26, 2003 - 6:11 pm: |
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To see if the noise is comming thru the antenna just unscrew the antenna. If the noise does not stop it is not comming in thru the antenna.
It could be Alternator Whine. Run the power wires directly to the battery terminals/both the + and -. Inside the cab install a noise filter as sold by radio shack if the direct battery connection does not eliminate the whine.
ALSO while you are at it, strip off some shield from some coax. Bond/jump the hood, all the doors and the trunk to the chassis ground. Some even go so far as to bond the exhaust system to the chassis using stainless pipe clamps.
DE |
Red Bird
| | Posted on Wednesday, March 26, 2003 - 6:26 pm: |
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It goes away when i turn off the ignition... |
Red Bird
| | Posted on Thursday, March 27, 2003 - 7:11 pm: |
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I tried the direct battery hookup and no change. I even think it made the noise worse than before. I unhooked the antenna and the noise goes bye bye. I had a mobile in this vehicke once before and i ended up removing it because of the very same problem... As a last resort ill get a trunk lip mount and a wilson silverload whip and try that trick and if i cant fix the problem ill remove the radio and not have one in my car... |
Simon
| | Posted on Friday, March 28, 2003 - 10:41 am: |
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Wrap several turns ofthe coax thru a toroid core - try it both inone directionand if no good try itby winding halfthe core one way then figure 8 itand wind the otherhalf in the over direction. Do the same thing with the power leadand even add a 0.01ufand a 1uf capacitor from positve lead(red) to ground.Inmy experience (commercial two-ways and military radios) these trick will quite oftenwork. |
Alsworld
| | Posted on Friday, March 28, 2003 - 11:35 am: |
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Red Bird, here is a great link. Hope it helps
http://www.k2bj.com/Pages/Noise/Intro.htm
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Kiwikid
| | Posted on Friday, March 28, 2003 - 5:22 pm: |
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Hello Team,Red Bird there is no one single cure for auto RFI problems.You may find that you will have to try many techniques to get rid of the whine.Try dropping the alternator drivebelt and run the engine to see if you still get the noise.You could also try a choke on the alternator output lead to the battery.It would have to be substancial to carry the maximun current the alternator could produce.Tread lighly and carefully and you will get there.Good luck.
73 Kiwi Kid |
Red Bird
| | Posted on Friday, March 28, 2003 - 9:05 pm: |
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I cannot drop the alt because it is on a serpatine belt.. If worse comes to worse ill just not have a mobile radio in my car..... |
Kiwikid
| | Posted on Friday, March 28, 2003 - 11:29 pm: |
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RED BIRD you can for a short test to see if it actually is the alternator doing the damage.Do forget the shut the hood when testing
Cheers |
Red Bird
| | Posted on Saturday, March 29, 2003 - 3:49 pm: |
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I moved my antenna to the top of the car and some of the noise did drop but i still get it.. I used to own a ranger RG 99 and i never had any problems with noise like i do now.. Also had a HR 2510 and it was not this bad.. Could the magnet mount antenna be the cause? I know they are not the best for grounding (almost NO ground mounted on the trunk with the magnet and no direct ground to the chassis) and one of my radio buds told me to try a trunk mount kit with a cheapie antenna that you cna buy at a truck stop and if that helps get a better antenna like a wilson silverload and run that! Im not gonna give up yet. |
Red Bird
| | Posted on Saturday, March 29, 2003 - 6:14 pm: |
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As a sidenote..
Iver noticed some reduction in noise after i moved my antenna but im still gonna try a few other options including getting a trunk mount kit and a top loaded antenna to see if it helps... Sure looks funny up on the top of the car!!!! I was told if i get the load section up and as far away from the engine as i can it will help the interference... |
Bigbob
| | Posted on Saturday, March 29, 2003 - 9:51 pm: |
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I got a '96 chevy pickup,a wilson silver load picks up more noise not less on mine,but by the same token has better ears,also gets out better because the current node is at the top instead of at the bottom,e.g.wilson 1000,it sees a further horizon,got a 5 footer.Best talkin antenna I ever had,gonna put it back on too. |
Kiwikid
| | Posted on Sunday, March 30, 2003 - 5:34 am: |
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Hello Team,
While we are on the topic of static,whine etc etc what radio did you find had the best noise blanker.From my experience dedicated 40CH.CB radios i.e. UNIDEN/PRESIDENT GRANT followed by Kenwood TS50S both well ahead of the Yaesu FT900CAT,FT100D and the FT747GX
73 Kiwi Kid |
Red Bird
| | Posted on Sunday, March 30, 2003 - 2:33 pm: |
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I dunno but my cobra 29 LTD classic has a horrible NB/ANL circuit IMHO....
BTW why doesnt Coppers sell a trunk mount kit? I cant find one... |
Bigbob
| | Posted on Sunday, March 30, 2003 - 4:26 pm: |
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PRESIDENT P 400 by regency(uniden)but you need a big cockpit,lol. |
Alsworld
| | Posted on Sunday, March 30, 2003 - 5:39 pm: |
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President Lincoln has a great NB.
Red Bird, is your vehicle due for a tuneup? New resistor spark plugs, rotor and distributor cap may help. Suppresion plug wires as well if needed. High performance does not always mean a good noise suppresor, although some manufactures do well there. I am working the same issue now including grounding much of the body to the frame, engine block, etc. A tuneup done yesterday helped a bunch. The long lasting platinum spark plugs were bad for noise in my case. Splitfires I imagine would have been extremely noisy. I also receive it through my antenna but it's improving considerably the more I do. Very tolerable now and virtually non-existent with the NB on.
Alsworld |
Red Bird
| | Posted on Sunday, March 30, 2003 - 7:56 pm: |
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I had the car tuned up this past fall.
I moved my antenna to the roof and some of the noise went away but i still have some of the whine.. Im thinking part of the problem is the magnet mount antenna itself.. |
Kiwikid
| | Posted on Monday, March 31, 2003 - 4:58 am: |
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Hello Team,This may work for ignition static:
It don't look to good under the hood but you may be able to screen ignition static with RG213 outer copper braid sleaved over the HT leads and earthed out at a common ground point at both ends and a fine metal insect mesh netting blanket,grounded at as many sides as possible, over the HT side off the engine.Also move the ignition coil from the inner fender/firewall direct onto the engine block,keeping the coil to dist.cap HT lead as short as possible.
73 Kiwi Kid |
Red Bird
| | Posted on Monday, March 31, 2003 - 8:30 pm: |
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Ok heres an update.
I took the antenna and removed the plastic stuff off of the bottom of the magnet exsposing the magnet itself.. It didnt make a bit of diff on the radios recever end at all. So i moved the antenna around to diff parts of the car and was suprised to find that if i stuck it on the hood the noise faded but if i moved it towards the back trunk of the car the noise got worse!!! Bad fuel pump perhaps causing the noise???? I tried the choke deal that i got from Rat shack and no dice. Last resort might be the trunk mount kit and a cheap antenna.... |
Bigbob
| | Posted on Monday, March 31, 2003 - 8:40 pm: |
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Bad move for the coil,there's a reason it's on fender/firewall,engine vibration will greatly shorten it's life,you don't wanna replace one unless you have to,pricey!Get a ballpeen hammer and some sheet aluminum and form a shield to fit around it,then ground it with heavy gauge copper strap,quite easy as a matter of fact.Change all ht leads to stainless core 7mm or 8mm wire,will produce enough supression for all concerned,and prevent breaks which cause rfi,neat huh.A lot less cobbling and much neater looking,wire comes in neon colors too,if that's your thing. |
Tech671
| | Posted on Tuesday, April 01, 2003 - 5:01 am: |
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Instead of installing the filter on the radio, install it on the fuel pump wires right where they enter the tank. The fuel pump is the culprit.
*****WARNING*****
It is suggested to disconnect battery when doing this! If you are not confident have your dealer perform this. |
Red Bird
| | Posted on Tuesday, April 01, 2003 - 7:13 pm: |
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Ill try the filter method (isnt that a 1990s alternative rock group?) tnext. What kind of filter do i need to look for? I am feeling fairly certain that the trouble maker is the fuel pump. Im not gonna give up yet guys!!!!!!!!!!!!! |
Tech671
| | Posted on Wednesday, April 02, 2003 - 5:30 am: |
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Pick up the best filter Rat Shack has or order the Magnum filter from Copper. Make sure to solder well and seal/insulate the bare connections. |
Tech808
| | Posted on Wednesday, April 02, 2003 - 7:58 pm: |
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Try the MAGNUM DC Power Line Filter From Copper.
The nice thing about this filter is it re-places your STOCK power cord to radio.
Hooks direct to Battery, Is FUSED and comes with plug for your radio.
Have sold many of these in our shop and everyone has been pleased.
Saves splicing wires to put filter inline.
Just my thought's
Lon
Tech808 |
bullet
| | Posted on Wednesday, April 02, 2003 - 9:33 pm: |
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capacitors the higher the farad value the better to kill noise. always has worked for me.
bullet. |
Kiwikid
| | Posted on Thursday, April 03, 2003 - 6:40 am: |
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Hello Team
Red Bird,have you tried hooking up another radio to see if you still get the whine? |
Red Bird
| | Posted on Saturday, April 05, 2003 - 7:08 am: |
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Yes i hooked up my other rigs and i still have the noise. Dont LOL but i even tried my Cobra 142GTL and hooked it up to 12 volts and it was even worse than the 29!!! |
Moderator558
| | Posted on Saturday, April 05, 2003 - 9:28 am: |
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try this:
CAR ON = NOISE
SIMPLY UNPLUG ALTERNATOR (NOT REMOVE BELT) = NOISE????
CAR OFF KEY ON (ALTERNATOR PLUGGED BACK IN) SIT IN CAR WITH CB RADIO ON AND LISTEN CAREFULLY AS YOU TURN ON THE KEY BUT DONT START CAR AND LISTEN FOR THE NOISE,,,THE NOISE WILL BE QUICK AS THE FUEL PUMP WILL ONLY TURN ON FOR A INSTANT WITH THE ENGINE NOT RUNNING AND THEN IT WILL SHUT OFF AGAIN. = NOISE???????
IF NOISE IS STILL PRESENT SHUT KEY OFF UNPLUG FUSE TO FUEL PUMP AND REPEAT ABOVE STEP =NOISE????
LET US KNOW |
Moderator558
| | Posted on Saturday, April 05, 2003 - 9:37 am: |
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look here as well
http://service.gm.com/techlineinfo/radio.html
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Weakeststation
| | Posted on Saturday, April 05, 2003 - 4:41 pm: |
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Simple, turn engine off and see if it does it then, if it don't, you know it's engine noise, if it does do it yet, you know it's the radio...
If its engine noise it can be a thousand diffrent things from plugs to fuel pump to harmonics from the engine, could be bad grounds tooo...
If it does do it with engine off, it may be a good idea to have your radio looked at, because this is then the cause, but make sure that when you do have the engine off that you are away from the house and power lines to try it... |
Bigbob
| | Posted on Sunday, April 06, 2003 - 11:35 pm: |
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JUST DO WHAT Tech 671 SAID,APRIL 01,AND BE DONE WITH IT,HE'S RIGHT! |
Simon
| | Posted on Monday, April 07, 2003 - 9:48 am: |
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redbird
About a week back I gave you suggestions that are used COMMERCIALLY and work in 99 out of a hundred cases. Try them. You can also add a .01uf capacitor from fule pump +ve lead to ground too. |
Red Bird
| | Posted on Monday, April 07, 2003 - 10:05 am: |
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With engine off the radio is stone dead quiet no noise and receiver is like it should be...
Ill try the trick with the alt and the fuel pump that 558 said.. I really dont think its the radio though.. Now i did remove the backing on the botom of the mag mount on the wilson 1000 and some of the noise has gone away! |
Simon
| | Posted on Tuesday, April 08, 2003 - 9:46 am: |
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WARNING!!!! Running some alternators without a load can damage the alternator..... |
Red Bird
| | Posted on Tuesday, April 08, 2003 - 11:13 pm: |
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Hello.
I tried the alt trick were you unhook the alt power leads and the noise went away! I had no noise at all in the radio besides the regular noise that you get on the air.. I hook them back uol and the noise came back so i belive its the Alt!! Now what can i do to get the noise to go away now that i know its the alt?? I work with a kid that is a car audio guru and he has some trick that he says will help out. I just need to get with him outside of work to have them done.. |
Bobtail
| | Posted on Sunday, June 01, 2003 - 10:33 am: |
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Red Bird
I installed a Texas star last night and souldered all connections, I also ran seperate 8 ga fine strain wire for radio and amp. (Radio was already in truck with no noise) when I turn radio on and started the truck I had a bad whine. I grounded the radio and amp with 10 ga wire to chassie and the noise is gone. Just a thought.. |
