Nitpicking CB install
Thread Starter
|
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
Nitpicking CB install
My CB has been on my truck for 2-3 years and I haven't done anything but remove the rusted spring. I have it a part, I added a ground wire (14ga about 4" below the mast, I have a nice mounting system but not a great ground), repainted my mount and have any rusty parts in my vibrating polisher. I think I am going to have to replace some hardware, it's rusted up pretty bad. Since I have to go to ACE tomorrow for hardware, will a cosmoline based anti-corrosion coating do any harm to the signal if it creeps?
Thread Starter
|
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
Well it's done and the bottom of the ball is coated in LPS3. I have just over a mile of range in the city. I haven't checked my SWRs, there are too many trees around, but it's strong.
I still can't get any decent voltages off the lead though. I still max out at 1.4VAC, which isn't nearly as high as it should be.
I still can't get any decent voltages off the lead though. I still max out at 1.4VAC, which isn't nearly as high as it should be.
Senior User
Joined: Jul 2003
Posts: 150
Likes: 0
From: Manchester, NH
cb help and questions
Don't ask me how this worked, but after I installed my antenna, while I was checking my SWR ratio I was unable to make it acceptable with a grounded mount. had to pull the ground off it and completely isolate the mount and outer shield of the coax from vehicle ground in all places with the exception of the back of the CB itself. might help you out a bit. What is this about measuring the voltage, i presume this is measuring the voltage off the antenna, done with a scope? what should the voltage be or is that ohms law? wattage/resistance? Has anyone seen a place where I can purchase some of those high output 12volt noise reducers. Would like to put one on my fuel pump, and CB possibly one on the output of the alternator if I can find one that does some 200+ amps. Anyone have some schematics where I can build one? Thanks for the help in advance, good luck with the cb.
//John
//John
Thread Starter
|
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
What kind of noise are you encountering?
It will be ohms law, the impedance of the system is 50 ohm, P=E*E over R. So find the AC voltage and square it, then divide it by 50 or .5 according to one website.
The noise your hearing is probably the ground on the radio. Move the ground somewhere else and see if the noise dissipates. Ground loops are the most common type of noise, I have a 230 amp alternator and no noise comes from it. The battery is best way to keep the alternator quiet, it absorbs the ripple from the 3 phase AC that is rectified, so if you battery if iffy, a new one might help.
Have you done the big three(alt-battery/engine-body/body-battery wires) upgrade yet?
It will be ohms law, the impedance of the system is 50 ohm, P=E*E over R. So find the AC voltage and square it, then divide it by 50 or .5 according to one website.
The noise your hearing is probably the ground on the radio. Move the ground somewhere else and see if the noise dissipates. Ground loops are the most common type of noise, I have a 230 amp alternator and no noise comes from it. The battery is best way to keep the alternator quiet, it absorbs the ripple from the 3 phase AC that is rectified, so if you battery if iffy, a new one might help.
Have you done the big three(alt-battery/engine-body/body-battery wires) upgrade yet?
Thread Starter
|
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
I don't think you can "reduce" the antenna's "noise" because it is AC voltage and needs to fluctuate. If you can find a device it will probably reduce the power output. I have read somewhere that ferrite cores around the coax helps, but I've had better luck winding the coax in to small coils.
For the DC powers, capacitors will remove high frequency noise and inductors will take care of low frequency noise. I can't remember if I ever learned how to spec a capacitor, but I'd think 1/4 farad would be sufficient. Or you can just buy a ground loop isolator from a stereo shop that will have capacitors and inductors built in.
For the DC powers, capacitors will remove high frequency noise and inductors will take care of low frequency noise. I can't remember if I ever learned how to spec a capacitor, but I'd think 1/4 farad would be sufficient. Or you can just buy a ground loop isolator from a stereo shop that will have capacitors and inductors built in.
