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Re: CB power
XS11E wrote:
> jeff <jalowe44.invalid@hotmail.com.invalid> wrote: > >> Any chassis ground is as effective as a separate ground lead. >> Metal to metal anywhere on a jeep should be less than an ohm. > > And that's EXACTLY why one isolates the antenna and CB in a Jeep to > avoid ground loops. Jeeps are notorious for not having good grounds, > particularly back in the days when CBs were more common. It was very > difficult to get a good noise free signal in Wagoneers and Cherokees > leading to the development of isolated mountings to avoid ground loops. > > Grounding the antenna to the body (as most installations do) is > surprisingly unsuccessful when the body grounds are rusted away. > > > If you use the vehicle chassis as a ground in a new GM vehicle, you will void the warranty for 'all' on board electronics of the vehicle. This includes things like the ABS controller, ignition, etc... You need to isolate transmitters these days. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pi...?id=2115147590 (More Off Road album links at bottom of the view page) |
Re: CB power
XS11E wrote:
> jeff <jalowe44.invalid@hotmail.com.invalid> wrote: > >> Any chassis ground is as effective as a separate ground lead. >> Metal to metal anywhere on a jeep should be less than an ohm. > > And that's EXACTLY why one isolates the antenna and CB in a Jeep to > avoid ground loops. Jeeps are notorious for not having good grounds, > particularly back in the days when CBs were more common. It was very > difficult to get a good noise free signal in Wagoneers and Cherokees > leading to the development of isolated mountings to avoid ground loops. > > Grounding the antenna to the body (as most installations do) is > surprisingly unsuccessful when the body grounds are rusted away. > > > If you use the vehicle chassis as a ground in a new GM vehicle, you will void the warranty for 'all' on board electronics of the vehicle. This includes things like the ABS controller, ignition, etc... You need to isolate transmitters these days. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pi...?id=2115147590 (More Off Road album links at bottom of the view page) |
Re: CB power
XS11E wrote:
> jeff <jalowe44.invalid@hotmail.com.invalid> wrote: > >> Any chassis ground is as effective as a separate ground lead. >> Metal to metal anywhere on a jeep should be less than an ohm. > > And that's EXACTLY why one isolates the antenna and CB in a Jeep to > avoid ground loops. Jeeps are notorious for not having good grounds, > particularly back in the days when CBs were more common. It was very > difficult to get a good noise free signal in Wagoneers and Cherokees > leading to the development of isolated mountings to avoid ground loops. > > Grounding the antenna to the body (as most installations do) is > surprisingly unsuccessful when the body grounds are rusted away. > > > If you use the vehicle chassis as a ground in a new GM vehicle, you will void the warranty for 'all' on board electronics of the vehicle. This includes things like the ABS controller, ignition, etc... You need to isolate transmitters these days. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pi...?id=2115147590 (More Off Road album links at bottom of the view page) |
Re: CB power
FrankW wrote:
> Sorry but you got it wrong... > Unless the antenna is one of those "no-ground plane" types > The antenna base MUST be grounded. The vehicle body > (otherwise known as the ground plane) is part of the antenna. > Please show me an example of a "isolated mounting". > Where do you buy them? > Everywhere Frank. The mag mounts are totally isolated 'electrically' but require a 3' circle of metal under them for the best 'reflective' ground plane. The vertical clamp on ones have a nylon insert where the stick meets the metal bracket if you look close. These also need a 'reflective' ground plane. A 'reflective' ground plane is an area for the signal to bounce off of increasing the range of the antenna. This is 'not' an 'electrical' ground. I use a trucker's mirror mount on my 'glass bodied CJ7 designed for no or little 'ground plane' and get excellent reception with an old Cobra 23. I have had 2 way conversations from Toronto Canada to Marthas Vineyard on the US east coast and pick up the Mississippi river truckers all the time. I wheel up on the Canadian Shield south of James Bay and can 'receive only' a gent on British Columbia's Sunshine Coast on the Pacific Ocean regularly from one area. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pi...?id=2115147590 (More Off Road album links at bottom of the view page) |
Re: CB power
FrankW wrote:
> Sorry but you got it wrong... > Unless the antenna is one of those "no-ground plane" types > The antenna base MUST be grounded. The vehicle body > (otherwise known as the ground plane) is part of the antenna. > Please show me an example of a "isolated mounting". > Where do you buy them? > Everywhere Frank. The mag mounts are totally isolated 'electrically' but require a 3' circle of metal under them for the best 'reflective' ground plane. The vertical clamp on ones have a nylon insert where the stick meets the metal bracket if you look close. These also need a 'reflective' ground plane. A 'reflective' ground plane is an area for the signal to bounce off of increasing the range of the antenna. This is 'not' an 'electrical' ground. I use a trucker's mirror mount on my 'glass bodied CJ7 designed for no or little 'ground plane' and get excellent reception with an old Cobra 23. I have had 2 way conversations from Toronto Canada to Marthas Vineyard on the US east coast and pick up the Mississippi river truckers all the time. I wheel up on the Canadian Shield south of James Bay and can 'receive only' a gent on British Columbia's Sunshine Coast on the Pacific Ocean regularly from one area. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pi...?id=2115147590 (More Off Road album links at bottom of the view page) |
Re: CB power
FrankW wrote:
> Sorry but you got it wrong... > Unless the antenna is one of those "no-ground plane" types > The antenna base MUST be grounded. The vehicle body > (otherwise known as the ground plane) is part of the antenna. > Please show me an example of a "isolated mounting". > Where do you buy them? > Everywhere Frank. The mag mounts are totally isolated 'electrically' but require a 3' circle of metal under them for the best 'reflective' ground plane. The vertical clamp on ones have a nylon insert where the stick meets the metal bracket if you look close. These also need a 'reflective' ground plane. A 'reflective' ground plane is an area for the signal to bounce off of increasing the range of the antenna. This is 'not' an 'electrical' ground. I use a trucker's mirror mount on my 'glass bodied CJ7 designed for no or little 'ground plane' and get excellent reception with an old Cobra 23. I have had 2 way conversations from Toronto Canada to Marthas Vineyard on the US east coast and pick up the Mississippi river truckers all the time. I wheel up on the Canadian Shield south of James Bay and can 'receive only' a gent on British Columbia's Sunshine Coast on the Pacific Ocean regularly from one area. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pi...?id=2115147590 (More Off Road album links at bottom of the view page) |
Re: CB power
FrankW wrote:
> Sorry but you got it wrong... > Unless the antenna is one of those "no-ground plane" types > The antenna base MUST be grounded. The vehicle body > (otherwise known as the ground plane) is part of the antenna. > Please show me an example of a "isolated mounting". > Where do you buy them? > Everywhere Frank. The mag mounts are totally isolated 'electrically' but require a 3' circle of metal under them for the best 'reflective' ground plane. The vertical clamp on ones have a nylon insert where the stick meets the metal bracket if you look close. These also need a 'reflective' ground plane. A 'reflective' ground plane is an area for the signal to bounce off of increasing the range of the antenna. This is 'not' an 'electrical' ground. I use a trucker's mirror mount on my 'glass bodied CJ7 designed for no or little 'ground plane' and get excellent reception with an old Cobra 23. I have had 2 way conversations from Toronto Canada to Marthas Vineyard on the US east coast and pick up the Mississippi river truckers all the time. I wheel up on the Canadian Shield south of James Bay and can 'receive only' a gent on British Columbia's Sunshine Coast on the Pacific Ocean regularly from one area. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pi...?id=2115147590 (More Off Road album links at bottom of the view page) |
Re: CB power
A 'ground plane' is a reflective area for amplifying the signal.
An 'electrical' ground is a power path. The 'only' thing they have in common is the word 'ground', nothing else. If you use an electrical ground for the transmitter's ground plane, you will void the vehicle's warranty for all things electronic according to all the manufacturers I have dealt with while installing and servicing transmitters for 9 years. Here is a link to the GM book and others posted links to the Ford and Chrysler books. http://service.gm.com/techlineinfo/radio.html http://www.fordemc.com/docs/download...adio_Guide.pdf http://www.neons.org/neontsb/TSB/08/081698.htm When in doubt, RTFM eh. OK, so I just did and WOW, the person who wrote the Neon one also has the electrical and reflective grounds mixed up in his head but at least he refers to the TSB which is correct. 3rd party websites are only as good as the person typing the garbage in... GIGO eh. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pi...?id=2115147590 (More Off Road album links at bottom of the view page) L. Ron Waddle wrote: > Nathan Otis wrote: >> >> Hey fellas. I'm wiring a new CB tomorrow and I want to do it right. I >> can't find the exact answer I'm looking for on the All Seeing Eye, so >> here I am. >> >> When wiring power, I understand it's best to go to the source >> (battery). What I don't know is... >> >> 1. Should BOTH the red AND black wire be connected to the battery @ >> pos and neg terminals respectively? >> >> 2. If not, then the black wire should be attached to ground, but where? >> >> 2a. Should I ground in the engine compartment or... >> >> 2b. Is it best to make the ground wire as short as possible (i.e., >> shorten the black wire to around a foot or two and ground in the cab)? > > Since you are getting contradictory information, here is what I have > gathered on the subject: > > 1. Power: Go straight to the battery. > 2. Ground: > The following are grounded on the typical radio: > a) power ground > b) antenna wire at radio (ground sheath) > c) antenna wire at antenna (ground sheath) > > You want to prevent ground loops as much as possible. Thus the > correct answer is that whatever you're attaching your ground to on the > antenna end (usually a metal antenna mount bolted to your bumper or > fender) should be what you attach the ground to on the CB end. Since the > antenna is generally bolted to the body (or has a low-ohm AC path to > ground through the magnetic mount attached to the body), that, then, is > what you should attach your CB ground to. > > > In short, the best ground is to attach your CB ground to one of the > sheet metal screws that you use to attach your CB to the body of the > Jeep. If you are not attaching the CB to the body of the Jeep, the > ground should instead be attached to the body as close to the CB as > possible. The goal is to provide a good ground path between the CB > ground and the antenna ground for use as a ground plane without worrying > about whether there is enough corrosion on the cable that grounds the > body to the battery to affect its impedence and thus cause it to serve > as an extension of the antenna (a.k.a. "ground loop"). > > Note that there are antenna setups which do not require a ground plane. > These use a fixed-length cable with a specified impedence and an > insulated ungrounded antenna. These generally, however, provide a poorer > reception on any metal vehicle that has sufficient steel for a proper > ground plane. Short of attaching a radial-element base station antenna > to your Jeep (which uses the radial elements as the ground plane, but > it'd make your Jeep kinda tall!), you cannot get a good ground plane > with a "groundplane-free" mobile setup. My handi-talkie CB with the > mini-whip does not get anywhere near as good of reception as my properly > grounded Firestick antenna, even if I attach the auxiliary antenna and > place it on top of my Jeep so it's as high as the Firestick on the back > of my Jeep. And this is despite the fact that the actual guts of this > handi-talkie are absolutely identical to the guts of my > permanently-mounted CB (both are Cobra designs and utilize the exact > same circuit board internally, all that differs is the surrounding > packaging, one is an all-in-mike design with a power/antenna box under > the dash and the other is a handi-talky with the power and antenna as > part of the package). The ground plane of the Jeep thus empirically has > proven to be quite a bit more effective at receiving signals than the > ground-plane-less approach, and you shouldn't even think about a > ground-plane-less approach for your antenna setup. > > -Elron |
Re: CB power
A 'ground plane' is a reflective area for amplifying the signal.
An 'electrical' ground is a power path. The 'only' thing they have in common is the word 'ground', nothing else. If you use an electrical ground for the transmitter's ground plane, you will void the vehicle's warranty for all things electronic according to all the manufacturers I have dealt with while installing and servicing transmitters for 9 years. Here is a link to the GM book and others posted links to the Ford and Chrysler books. http://service.gm.com/techlineinfo/radio.html http://www.fordemc.com/docs/download...adio_Guide.pdf http://www.neons.org/neontsb/TSB/08/081698.htm When in doubt, RTFM eh. OK, so I just did and WOW, the person who wrote the Neon one also has the electrical and reflective grounds mixed up in his head but at least he refers to the TSB which is correct. 3rd party websites are only as good as the person typing the garbage in... GIGO eh. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pi...?id=2115147590 (More Off Road album links at bottom of the view page) L. Ron Waddle wrote: > Nathan Otis wrote: >> >> Hey fellas. I'm wiring a new CB tomorrow and I want to do it right. I >> can't find the exact answer I'm looking for on the All Seeing Eye, so >> here I am. >> >> When wiring power, I understand it's best to go to the source >> (battery). What I don't know is... >> >> 1. Should BOTH the red AND black wire be connected to the battery @ >> pos and neg terminals respectively? >> >> 2. If not, then the black wire should be attached to ground, but where? >> >> 2a. Should I ground in the engine compartment or... >> >> 2b. Is it best to make the ground wire as short as possible (i.e., >> shorten the black wire to around a foot or two and ground in the cab)? > > Since you are getting contradictory information, here is what I have > gathered on the subject: > > 1. Power: Go straight to the battery. > 2. Ground: > The following are grounded on the typical radio: > a) power ground > b) antenna wire at radio (ground sheath) > c) antenna wire at antenna (ground sheath) > > You want to prevent ground loops as much as possible. Thus the > correct answer is that whatever you're attaching your ground to on the > antenna end (usually a metal antenna mount bolted to your bumper or > fender) should be what you attach the ground to on the CB end. Since the > antenna is generally bolted to the body (or has a low-ohm AC path to > ground through the magnetic mount attached to the body), that, then, is > what you should attach your CB ground to. > > > In short, the best ground is to attach your CB ground to one of the > sheet metal screws that you use to attach your CB to the body of the > Jeep. If you are not attaching the CB to the body of the Jeep, the > ground should instead be attached to the body as close to the CB as > possible. The goal is to provide a good ground path between the CB > ground and the antenna ground for use as a ground plane without worrying > about whether there is enough corrosion on the cable that grounds the > body to the battery to affect its impedence and thus cause it to serve > as an extension of the antenna (a.k.a. "ground loop"). > > Note that there are antenna setups which do not require a ground plane. > These use a fixed-length cable with a specified impedence and an > insulated ungrounded antenna. These generally, however, provide a poorer > reception on any metal vehicle that has sufficient steel for a proper > ground plane. Short of attaching a radial-element base station antenna > to your Jeep (which uses the radial elements as the ground plane, but > it'd make your Jeep kinda tall!), you cannot get a good ground plane > with a "groundplane-free" mobile setup. My handi-talkie CB with the > mini-whip does not get anywhere near as good of reception as my properly > grounded Firestick antenna, even if I attach the auxiliary antenna and > place it on top of my Jeep so it's as high as the Firestick on the back > of my Jeep. And this is despite the fact that the actual guts of this > handi-talkie are absolutely identical to the guts of my > permanently-mounted CB (both are Cobra designs and utilize the exact > same circuit board internally, all that differs is the surrounding > packaging, one is an all-in-mike design with a power/antenna box under > the dash and the other is a handi-talky with the power and antenna as > part of the package). The ground plane of the Jeep thus empirically has > proven to be quite a bit more effective at receiving signals than the > ground-plane-less approach, and you shouldn't even think about a > ground-plane-less approach for your antenna setup. > > -Elron |
Re: CB power
A 'ground plane' is a reflective area for amplifying the signal.
An 'electrical' ground is a power path. The 'only' thing they have in common is the word 'ground', nothing else. If you use an electrical ground for the transmitter's ground plane, you will void the vehicle's warranty for all things electronic according to all the manufacturers I have dealt with while installing and servicing transmitters for 9 years. Here is a link to the GM book and others posted links to the Ford and Chrysler books. http://service.gm.com/techlineinfo/radio.html http://www.fordemc.com/docs/download...adio_Guide.pdf http://www.neons.org/neontsb/TSB/08/081698.htm When in doubt, RTFM eh. OK, so I just did and WOW, the person who wrote the Neon one also has the electrical and reflective grounds mixed up in his head but at least he refers to the TSB which is correct. 3rd party websites are only as good as the person typing the garbage in... GIGO eh. Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pi...?id=2115147590 (More Off Road album links at bottom of the view page) L. Ron Waddle wrote: > Nathan Otis wrote: >> >> Hey fellas. I'm wiring a new CB tomorrow and I want to do it right. I >> can't find the exact answer I'm looking for on the All Seeing Eye, so >> here I am. >> >> When wiring power, I understand it's best to go to the source >> (battery). What I don't know is... >> >> 1. Should BOTH the red AND black wire be connected to the battery @ >> pos and neg terminals respectively? >> >> 2. If not, then the black wire should be attached to ground, but where? >> >> 2a. Should I ground in the engine compartment or... >> >> 2b. Is it best to make the ground wire as short as possible (i.e., >> shorten the black wire to around a foot or two and ground in the cab)? > > Since you are getting contradictory information, here is what I have > gathered on the subject: > > 1. Power: Go straight to the battery. > 2. Ground: > The following are grounded on the typical radio: > a) power ground > b) antenna wire at radio (ground sheath) > c) antenna wire at antenna (ground sheath) > > You want to prevent ground loops as much as possible. Thus the > correct answer is that whatever you're attaching your ground to on the > antenna end (usually a metal antenna mount bolted to your bumper or > fender) should be what you attach the ground to on the CB end. Since the > antenna is generally bolted to the body (or has a low-ohm AC path to > ground through the magnetic mount attached to the body), that, then, is > what you should attach your CB ground to. > > > In short, the best ground is to attach your CB ground to one of the > sheet metal screws that you use to attach your CB to the body of the > Jeep. If you are not attaching the CB to the body of the Jeep, the > ground should instead be attached to the body as close to the CB as > possible. The goal is to provide a good ground path between the CB > ground and the antenna ground for use as a ground plane without worrying > about whether there is enough corrosion on the cable that grounds the > body to the battery to affect its impedence and thus cause it to serve > as an extension of the antenna (a.k.a. "ground loop"). > > Note that there are antenna setups which do not require a ground plane. > These use a fixed-length cable with a specified impedence and an > insulated ungrounded antenna. These generally, however, provide a poorer > reception on any metal vehicle that has sufficient steel for a proper > ground plane. Short of attaching a radial-element base station antenna > to your Jeep (which uses the radial elements as the ground plane, but > it'd make your Jeep kinda tall!), you cannot get a good ground plane > with a "groundplane-free" mobile setup. My handi-talkie CB with the > mini-whip does not get anywhere near as good of reception as my properly > grounded Firestick antenna, even if I attach the auxiliary antenna and > place it on top of my Jeep so it's as high as the Firestick on the back > of my Jeep. And this is despite the fact that the actual guts of this > handi-talkie are absolutely identical to the guts of my > permanently-mounted CB (both are Cobra designs and utilize the exact > same circuit board internally, all that differs is the surrounding > packaging, one is an all-in-mike design with a power/antenna box under > the dash and the other is a handi-talky with the power and antenna as > part of the package). The ground plane of the Jeep thus empirically has > proven to be quite a bit more effective at receiving signals than the > ground-plane-less approach, and you shouldn't even think about a > ground-plane-less approach for your antenna setup. > > -Elron |
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