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#1
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I drive a 9900 International. I am getting a loud whine in the CB speaker,
but not in the radio speakers, even though they share the dual antennas. The whine increases and decreases with the rpms of the motor. After disconnecting the coax from the CB transceiver the whine is gone. Does this mean the coax or antennas are definitely the problem? ... or are they just picking up on a problem with the alternator? The coax will be extremely hard to replace, maybe impossible since this is a company truck. The alternator would probably be easier to repair. Any help to eliminate or even reduce the whine would be greatly appreciated. |
#2
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"Randy" wrote:
I drive a 9900 International. I am getting a loud whine in the CB speaker, but not in the radio speakers, even though they share the dual antennas. The whine increases and decreases with the rpms of the motor. After disconnecting the coax from the CB transceiver the whine is gone. Does this mean the coax or antennas are definitely the problem? ... or are they just picking up on a problem with the alternator? The coax will be extremely hard to replace, maybe impossible since this is a company truck. The alternator would probably be easier to repair. Any help to eliminate or even reduce the whine would be greatly appreciated. Sounds like not enough ground on your antenna. How's your swr? -- http://www.allpar.com/mopar.html |
#3
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In , "Randy" wrote:
I drive a 9900 International. I am getting a loud whine in the CB speaker, but not in the radio speakers, even though they share the dual antennas. The whine increases and decreases with the rpms of the motor. After disconnecting the coax from the CB transceiver the whine is gone. Does this mean the coax or antennas are definitely the problem? ... or are they just picking up on a problem with the alternator? The coax will be extremely hard to replace, maybe impossible since this is a company truck. The alternator would probably be easier to repair. Any help to eliminate or even reduce the whine would be greatly appreciated. What brand/model radio are you using? -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#4
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![]() "Steveo" wrote in message ... "Randy" wrote: I drive a 9900 International. I am getting a loud whine in the CB speaker, but not in the radio speakers, even though they share the dual antennas. The whine increases and decreases with the rpms of the motor. After disconnecting the coax from the CB transceiver the whine is gone. Does this mean the coax or antennas are definitely the problem? ... or are they just picking up on a problem with the alternator? The coax will be extremely hard to replace, maybe impossible since this is a company truck. The alternator would probably be easier to repair. Any help to eliminate or even reduce the whine would be greatly appreciated. Sounds like not enough ground on your antenna. How's your swr? -- http://www.allpar.com/mopar.html swr is ~ 3 I am just learning about CB radios. I know the antennas are using plastic inserts to keep them from being grounded. I am using Firestik II antennas and have not tried adjusting them yet. I thought I needed to eliminate the whine first. This International has a fiberglass top making for a bad ground plane, from what I have been reading. That is about all I know of my situation. |
#5
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![]() "Frank Gilliland" wrote in message ... In , "Randy" wrote: I drive a 9900 International. I am getting a loud whine in the CB speaker, but not in the radio speakers, even though they share the dual antennas. The whine increases and decreases with the rpms of the motor. After disconnecting the coax from the CB transceiver the whine is gone. Does this mean the coax or antennas are definitely the problem? ... or are they just picking up on a problem with the alternator? The coax will be extremely hard to replace, maybe impossible since this is a company truck. The alternator would probably be easier to repair. Any help to eliminate or even reduce the whine would be greatly appreciated. What brand/model radio are you using? I am using a Cobra 29 NW right out of the box. Antennas are 4' Firestiks II swr ~ 3 |
#6
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"Randy" wrote:
I am using a Cobra 29 NW right out of the box. Antennas are 4' Firestiks II swr ~ 3 swr - 3? you got problems and dual antenna's suck. Try using just one of them. -- http://www.allpar.com/mopar.html |
#7
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"Randy" wrote:
"Steveo" wrote in message ... "Randy" wrote: I drive a 9900 International. I am getting a loud whine in the CB speaker, but not in the radio speakers, even though they share the dual antennas. The whine increases and decreases with the rpms of the motor. After disconnecting the coax from the CB transceiver the whine is gone. Does this mean the coax or antennas are definitely the problem? ... or are they just picking up on a problem with the alternator? The coax will be extremely hard to replace, maybe impossible since this is a company truck. The alternator would probably be easier to repair. Any help to eliminate or even reduce the whine would be greatly appreciated. Sounds like not enough ground on your antenna. How's your swr? -- http://www.allpar.com/mopar.html swr is ~ 3 I am just learning about CB radios. I know the antennas are using plastic inserts to keep them from being grounded. I am using Firestik II antennas and have not tried adjusting them yet. I thought I needed to eliminate the whine first. This International has a fiberglass top making for a bad ground plane, from what I have been reading. That is about all I know of my situation. There's no stupid questions, Randy. The first thing to make sure of is your antenna, it's just like any other electrical connection and it has to be right. Good ground and swr and separation from the body metal just for starters. Some of that noise can be from the electric fuel pump on certain vehicles. Get your swr down to 1.5 or less for starters. You'll have to process of eliminate for any static after you know your antenna is working properly. They do sell filters for some of that noise, it goes on your hot lead. Longer is better for antenna's..you can un-screw it without getting out of the truck if you mirror mount it. -- http://www.allpar.com/mopar.html |
#8
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In , "Randy" wrote:
"Frank Gilliland" wrote in message .. . In , "Randy" wrote: I drive a 9900 International. I am getting a loud whine in the CB speaker, but not in the radio speakers, even though they share the dual antennas. The whine increases and decreases with the rpms of the motor. After disconnecting the coax from the CB transceiver the whine is gone. Does this mean the coax or antennas are definitely the problem? ... or are they just picking up on a problem with the alternator? The coax will be extremely hard to replace, maybe impossible since this is a company truck. The alternator would probably be easier to repair. Any help to eliminate or even reduce the whine would be greatly appreciated. What brand/model radio are you using? I am using a Cobra 29 NW right out of the box. Antennas are 4' Firestiks II swr ~ 3 Your SWR is high. High SWR isn't responsible for whine, but it is a good indicator of other problems. From what you said in your other post your cab roof is fiberglass, so you don't have any ground plane -at all- for your antenna. But even that isn't responsible for the whine. I suspect that the radio isn't very well grounded. The mounting bracket should be bolted directly to the dash or some other chassis metal, and the negative power lead should be as short as possible (inches) to the same. You can also try a noise filter on your positive power lead, and tap the wire as close to the radio as possible. That should eliminate your whine. It should also get your SWR down below 3. As for your antenna, you need to find a point on the rig where the antenna can be mounted directly to the chassis. A mirror mount is ok if the bracket and door are well grounded. A 9' whip on the front bumper isn't a bad choice either (don't forget to tie it back a bit so it doesn't flop around). You could also try one of those 'no-ground-plane' antennas but don't expect great results. Ask around the watering holes and see what others have done. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#9
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![]() "Steveo" wrote in message ... "Randy" wrote: I am using a Cobra 29 NW right out of the box. Antennas are 4' Firestiks II swr ~ 3 swr - 3? you got problems and dual antenna's suck. Try using just one of them. -- http://www.allpar.com/mopar.html I had this same setup on another truck of the same year and model without any whine. That setup also had a fairly high swr but zero whine. Are you suggesting that because I have high swr that this is somehow allowing this whine to be picked up by the antennas? .. or maybe causing the whine? What is actually causing the whine? |
#10
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"Randy" wrote:
"Steveo" wrote in message ... "Randy" wrote: I am using a Cobra 29 NW right out of the box. Antennas are 4' Firestiks II swr ~ 3 swr - 3? you got problems and dual antenna's suck. Try using just one of them. -- http://www.allpar.com/mopar.html I had this same setup on another truck of the same year and model without any whine. That setup also had a fairly high swr but zero whine. Are you suggesting that because I have high swr that this is somehow allowing this whine to be picked up by the antennas? .. or maybe causing the whine? What is actually causing the whine? I'm suggesting perhaps your transmitting off just your coax, with your swr being 3. Start with your antenna problems, then fix the whine. -- http://www.allpar.com/mopar.html |
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