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Message |
    
Livinginh
New member
Username: Livinginh
Post Number: 8
Registered: 4-2007
| | Posted on Sunday, May 06, 2007 - 12:42 am: | 
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I have alot of noise in my CB in my 95 PeterBuilt, I have to squelch to the point of not getting any recieve. It is coming from my electric fan, I have tried noise filters with no change, if I shut the fan off it goes away, but for many reasons I cant drive with out my engine fan during the summer. Does anyone know of a better way to hook this radio up to bypass this noise or a better filter to use? Any help would be great, thanks |
Road_warrior134
Member
Username: Road_warrior134
Post Number: 51
Registered: 12-2006
| | Posted on Sunday, May 06, 2007 - 8:00 am: |
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Just wondering , have you had the truck from new and if so is it a new problem or have you always had the noise problem , you can try grounding the fan motor casing to the chassis or if that don't work get the fan motor checked as it could be the cause of badly worn contacts or bushes , I had same problem on the truck I used to drive which I tried to ignore and one night well sure as hell the fan broke in the middle of nowhere  , hope this helps
JIM
Road Warrior134 / MM0TXO
CEF#858
HAM#230
CVC#116
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Livinginh
New member
Username: Livinginh
Post Number: 9
Registered: 4-2007
| | Posted on Sunday, May 06, 2007 - 4:26 pm: |
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Thanks for the reply, no I havnt had the truck since new, I just started with this company and moved my radio over to the truck. Thats when I found the problem.
As for grounding the fan motor, cant really, it is actually an electric fan clutch that locks the fan on or off. Kind of like your AC clutch would work, so there are no brushs. Never fails cant be something easy.
I will check and see if maybe there is a loss ground somewhere. |
Crackshot
Intermediate Member
Username: Crackshot
Post Number: 313
Registered: 10-2005
| | Posted on Sunday, May 06, 2007 - 6:01 pm: |
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have you tried to isolate to see if noise is coming through DC power or antenna?
KE7JFA
CEF 655
HAM 225
ARRL Member
ARRL PIO District 6
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Livinginh
Junior Member
Username: Livinginh
Post Number: 10
Registered: 4-2007
| | Posted on Sunday, May 06, 2007 - 7:21 pm: |
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Ok forgive me if I am not sure what you are asking. All I know is when I flip the switch off to the fan the noise quits, how would I figure out if it is coming from the antenna or the DC power? Thanks |
Crackshot
Intermediate Member
Username: Crackshot
Post Number: 314
Registered: 10-2005
| | Posted on Sunday, May 06, 2007 - 8:08 pm: |
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disconnect the coax from back of radio (do not transmit) and then turn on radio and start your fan. see if you get the same noise coming through radio.
BTW your avatar cracks me up! 
KE7JFA
CEF 655
HAM 225
ARRL Member
ARRL PIO District 6
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Dale
Advanced Member
Username: Dale
Post Number: 839
Registered: 12-2002
| | Posted on Sunday, May 06, 2007 - 10:23 pm: |
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crackshot is right but before that gotta ask how ya got radio wired up for its power.some places
are not the best and will produce this problem
dale/a.k.a.hotrod
cef426
cvc#64
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Livinginh
Junior Member
Username: Livinginh
Post Number: 11
Registered: 4-2007
| | Posted on Sunday, May 06, 2007 - 11:37 pm: |
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I'll try that on the coax tomorrow and see if that does any good. It is wired directly to the CB hook ups in the truck(factory location), I have no clue where they have that hooked too. Thanks on the avatar, I couldnt help it, brought a smile to me also. Thanks for all your help, I will up date tomorrow. |
Dale
Advanced Member
Username: Dale
Post Number: 845
Registered: 12-2002
| | Posted on Monday, May 07, 2007 - 5:45 am: |
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try hooking it to directly to battery.
dale/a.k.a.hotrod
cef426
cvc#64
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Tech237
Moderator
Username: Tech237
Post Number: 771
Registered: 4-2004
| | Posted on Monday, May 07, 2007 - 6:37 pm: |
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If mit coming on the power leads try taking a toroid core and wind any spare lead on the corer. Wind the first half so that it is clockwise and wind the second half so that it winds anti-clockwise.
Simon
Tech237
KD7IEB
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Livinginh
Junior Member
Username: Livinginh
Post Number: 12
Registered: 4-2007
| | Posted on Monday, May 07, 2007 - 8:29 pm: |
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Anti Clockwise???? Shouldnt that read Counter Clockwise,,,haha. Im just kidding.
Ok, I unhooked the antenna coax fromt he back of the radio with the truck running, radio on and fan on, no noise at all. So that means it is somewhere in my coax or antenna right???
I am running just standard coax, but it did it with 2 differant ones, so I dont think it is that. I am running one Wilson 2000 trucker antenna mounted on the drivers door mirror. Beings it is a fiberglass door, do you think I may need to ground the antenna to the body? I really appreciate all of the suggestions and help. You guys are great. Thanks again |
Livinginh
Junior Member
Username: Livinginh
Post Number: 13
Registered: 4-2007
| | Posted on Monday, May 07, 2007 - 11:28 pm: |
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The altinator is not very old, and way to expensive to change just for the radio,,haha. As for the coax, I did away with the factory one that ran through the body and put a new one on already, still the same. Could either a bad antenna ground or something aray in the antenna cause this problem? My SWR's are at 1.1 to 1.5 all the way through, so that not my problem. |
Im4jc
Intermediate Member
Username: Im4jc
Post Number: 238
Registered: 11-2005
| | Posted on Tuesday, May 08, 2007 - 1:12 am: |
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Livingnh: at first I thought you were talking about your blower motor for the heat/AC, but then you said it is engaged by a clutch. Any you talking about the engine fan that cools the engine and is belt driven?
If so, I had the exact same problem...loose belts. Yep, you heard me right...loose belts. When the belts slip, they cause HORRIFIC rfi on a big truck. Just tighten them or replace them.
However, if it's the blower motor, you're on your own. I've tried everything under the sun to get rid of my blower motor noise, but couldn't cure it. Then I finally DID cure it...I bought a Uniden Grant and I can barely hear the noise anymore. The Grant and other radios based on the MB8719 chassis have a far superior noise blanker than the modern exports do. I know that's not really a direct solution, but it's all I have. We used to have a forum member here who even went to the trouble to shield his blower motor housing with aluminum foil...but to no avail. These darn big trucks are pretty bad at blower motor noise. |
Crackshot
Intermediate Member
Username: Crackshot
Post Number: 315
Registered: 10-2005
| | Posted on Tuesday, May 08, 2007 - 7:16 am: |
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If its fiberglass door that antenna is mounted on, yes the antenna needs to be grounded and I am sure that is your problem.
KE7JFA
CEF 655
HAM 225
ARRL Member
ARRL PIO District 6
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Livinginh
Junior Member
Username: Livinginh
Post Number: 14
Registered: 4-2007
| | Posted on Tuesday, May 08, 2007 - 6:27 pm: |
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Yes it is the clutch fan that is belt driven, but usings an electric clutch to engage it.
I will try grounding the antenna and see if that works. I tried a differant antenna today just to see and it was the same.
I will keep you informed as to what works finally. |
Tech808
Moderator
Username: Tech808
Post Number: 13661
Registered: 8-2002
| | Posted on Tuesday, May 08, 2007 - 6:41 pm: |
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Livinginh,
#1 ~ Ground Antenna's/Antenna Mounts DIRECT to the tractor frame.
#2 ~ Run a Ground wire from a case screw on Radio DIRECT to tractor frame.
#3 ~ Go DIRECT to batteries for power.
Works great on our Pete 379 and Kenworth L900 and NO NOISE or PROBLEMS.
DO NOT USE ANY FACTORY INSTALLED WIRING for your Power or Ground or Factory installed COAX or Antennas for your radio.
Hope this help's,
Lon ~ Tech808 ~ N9CEF
CEF#808 ~ CEF HAM#33 ~ CVC#002
Tech808@copperelectronics.com
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Livinginh
Junior Member
Username: Livinginh
Post Number: 15
Registered: 4-2007
| | Posted on Tuesday, May 08, 2007 - 10:25 pm: |
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Thank you, I will do all that tomorrow, this is a 377 Pete, but basicly the same truck. I have already done away with the factory run coax. I appreciate everyones imput, you have been more then helpful. Have a great night.... |
Dmh
Junior Member
Username: Dmh
Post Number: 26
Registered: 5-2002
| | Posted on Thursday, June 07, 2007 - 1:59 pm: |
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I had the same problem with a different electric motor . This one went to the windshield wipers . I was picking up a noise of S-7 with the wipers on. My mechanic changed the wiper motor for me.....Got rid of the noise . Bad brushes I guess. Always keep a GOOD relationship with your mechanic , you disrespect him & he'll not do anything extra for you !! |
Kosmic
Junior Member
Username: Kosmic
Post Number: 40
Registered: 7-2006
| | Posted on Thursday, June 07, 2007 - 6:09 pm: |
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Found this with Sterlings also,
1) Power from Battery
2) Case Ground to Cab
3) Magnet wired with Ground on top of cab and connect to antenna mount (any old magnet mount will work, taking out the guts and using mag and metal shield
4) Run ground wire from cab to frame
Works on Sterling with fiberglase doors basically only way to get a positive ground with one.
Kosmic
CEF801
KI4TRX
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Hyperno_1979
Intermediate Member
Username: Hyperno_1979
Post Number: 349
Registered: 12-2005
| | Posted on Friday, June 08, 2007 - 8:15 am: |
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Rick,
Found this with all trucks when i used to be a steering wheel attendant, so i changed jobs and no interferrance. Cheers Mate.
CEFFFCEF
Bob
CEF703/CVC26
269 Hunter Valley
27.355 lsb.
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