Help needed with cb install.

Guys, I really like this forum and all the great help that is here. I have very little experience related directly to Model A's, but I have a lot of experience with ham radio, CB and other things electrical, both in vehicle and out. Rawhidekid, your advice in this forum has also been invaluable to me on many occasions.

I agree 100% with Rawhidekid that a better way to connect the CB would be to use a separate battery over using a converter particularly because of the transmitter.

I do not agree with the need to keep grounds separate, but that's just me. To me, grounds are very important and good bonding at ground potential is essential in any transmitter application. With a coaxial output from the transmitter, an ungrounded output can lead to weird RF transients, although at 5 watts, not enough to cause any problems. At higher wattages, RF can do really weird things.

Thanks,
 
RawhideKid said:
*rolls eyes* Ok folk, let me explain what is going to happen when the CB positive wire is connected to this device and the antenna is attached to the bumper bracket or something similar.


The first thing you will see when plugging in the antenna is a spark when the sleeve is slid up to start the thread. This spark is not good as it will probably blow the 3 amp fuse inline with the inverter. If a larger fuse is used, depending on how large, it too will blow, or should blow. If this fuse does not blow, we are still not out of the woods because something else that is electrically smaller than the fuse will start to heat up, or just start to smoke, and once you let the smoke out.....well, you know, you can't put it back.

Now, most likely the smoke will come out of the CB, at which time you will have toasted one or all of the chassis to black wire connections.
Click to expand...

The device that the OP has is made specifically for use in an automobile that has a 6 volt positive ground system (aka a stock Model A). Most of the Model A vendors sell this device. https://www.brattons.com/six-to-twelve-volt-inverter-2-5-amp.html

If his used inverter is working correctly and he hooks it up correctly nothing will be going up in smoke. I have one on my sedan and the antenna is grounded, the CB radio is grounded and the inverter is grounded all to the frame of the vehicle.

Using a separate 12 volt battery isn't necessary if you have the inverter.
 
Magicbox51 said:
I do not agree with the need to keep grounds separate, but that's just me. To me, grounds are very important and good bonding at ground potential is essential in any transmitter application. With a coaxial output from the transmitter, an ungrounded output can lead to weird RF transients, although at 5 watts, not enough to cause any problems. At higher wattages, RF can do really weird things.

Thanks,
Click to expand...

Well, with an SWR box that antenna is not only the chicken wire, but it is also the shield on the coax, the shield providing the ground plain potential and the chicken wire becoming the antemma. I have done something similar with an all fiberglass body vehicle. Had them install the wire into the roof while making the body in the mold. This was for a Baja 1000 team vehicle and it actually worked very well, was working 60+ miles with 25watts.

One thing folks fail to realize is that the CB is chassis Negative, and when you place the antenna shield to vehicle chassis, you now introduce a Positive battery potential to the chassis of the radio. Now, put 12v Positive at the red wire, which is radio above chassis potential, it does want to do funny things, not least of all, make smoke because you have reversed the polarity on the CB chassis. Now, I will not say that ALL the CB radios are this way because it has been a few decades since I was employed to remedy these situations and the industry has evolved, but I am thinking that the CB was pulled from a shelf where it has sat since the 70's or 80's and is not a brand new one with the possible new sophistication. We will see.
 
As others stated this is a voltage up converter that uses a common ground, it is designed to convert 6 volt positive ground systems to 12 volt negative ground. Using a common ground, these use a switching circuit to create the 12 volt side. Assuming the converter can produce the amount of current needed it will work. There will not be any smoke from an antenna as it is a common ground system. I have one of these in my A it works just fine for what I need.

Here is a link to posts about this in the past:
https://www.fordbarn.com/forum/showthread.php?t=93299
 
Ah ha! I will likely get one sometime for my 2-meter handheld VHF rig... The next biggest obstacle is that I don't seem to have the coordination to even drink a diet Coke, let alone try to find a frequency pre-set and dial it in, and try to find what place the mike had fallen into. I probably won't be able to hear a radio either! :(:mad:
 
UPDATE:

Installed everything and she powered up without smoke!! Definitely a little static interference so I will have to work on that part next. I wired the invertor to a accessory plug and was able to pretty much hide it. I mounted the antenna to the trunk and mounted the cb on the cowl panel.
Thank you to all for your help and advice. Heading out for a tour tomorrow with the club. We'll she how she goes..
Geoff
 

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Good job Jackson I read through all of the threads and finally a correct answer the man just wanted to know how to hook it up!!!
 
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