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Discussion Starter #1
yesterday I got my Cobra package from right channel radios. Got it mocked up in the cab because I wanted to test it before I did my final installation under the dash. Connected the SWR meter and followed the instructions on the sticky and kept getting a SWR well into the "red zone". So my question is to the guys who have this setup, did you have to modify the antenna mount in anyway for grounding? I'm pretty sure I have a bad ground because when I touch the antenna for adjustment my static would change (I adjusted the SQ so I could hear it when i was outside).
 

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more details please. where is your antenna mounted? do you have coax going straight to the antenna, or do you have one of those firestik mounts?

if you have one of those firestik mounts... throw it in the trash. go buy a bracket (piece of steel) from the home depot or someplace, throw it behind your tire carrier, and forget about the SWR meter. the handhelds (cobra 75WX - what i have) aren't tunable, yes.. the antenna's are... but it's almost pointless to try and tune the antenna.

.
 

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I've got antenna>spring>mount>coax on the tire carrier. Its the teraflex tire carrier mount for JK's.

I'm just wondering if it might have something to do with the placement of the nylon washer if that could be my issue.
 

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i have my washer on the top half.. if that helps. similar set up (used to have the same one) now the antenna is mounted on the TF hi-lift mount.
 

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Discussion Starter #5
i have my washer on the top half.. if that helps. similar set up (used to have the same one) now the antenna is mounted on the TF hi-lift mount.
Ok, I think I know what I'm doing wrong. I don't think I have the nylon washer separating the antenna from the mount. I need to rearrange that, and then test for grounding from the coax to the body. If no good ground still I'll need to grind some of the powder coating off, correct?
 

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I put the nylon washer on top and its worse now. According to that diagram I should have 2 nylon washers, only 1 was supplied with my kit...
 

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PSA: You must grind off the powdercoating...................... :whistling:
 

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I put the nylon washer on top and its worse now. According to that diagram I should have 2 nylon washers, only 1 was supplied with my kit...
I'm guessing ya got it fixed... but for future reference...

It depends on if you have a screw on or lug type connector for your mount. The top must have one... if the antenna is not isolated from ground you are basically dead-shorting every time you TX. This is bad.

As far as squelch, that is a gateway threshold to determine what naturally occuring or interfering radio signals are 'recieved', and anytime you are recieving and change the antennas ability to gather radio waves, by say holding it, it will change sound.

If you want a quick bonding test, clip jumper cables (4ga) to the mount and your frame... if swr improves, you are improperly/inadequately bonded. If your swr is above 3 across the board, you almost certainly have an installation problem (not simply bonding, or 'grounding').
 

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Discussion Starter #12
I'm guessing ya got it fixed... but for future reference...

It depends on if you have a screw on or lug type connector for your mount. The top must have one... if the antenna is not isolated from ground you are basically dead-shorting every time you TX. This is bad.

As far as squelch, that is a gateway threshold to determine what naturally occuring or interfering radio signals are 'recieved', and anytime you are recieving and change the antennas ability to gather radio waves, by say holding it, it will change sound.

If you want a quick bonding test, clip jumper cables (4ga) to the mount and your frame... if swr improves, you are improperly/inadequately bonded. If your swr is above 3 across the board, you almost certainly have an installation problem (not simply bonding, or 'grounding').

Honestly, I went into this thinking it was a plug and play type thing. When I finally broke out my meter, put on my electrical engineering boots I had it licked in about 5 minutes.

First I checked the coax cable, which tested good.

I checked continuity from the base to the top(past the nylon washer) and read open which was good.

Then I checked the continuity of my ground which I'm getting around 4 ohms. I'm not really pleased with that, but we'll see how it goes.

All said and done I got my SWR to around 2 maybe a little below. I know it isn't ideal, but I was running out of daylight and I'll play with it later when i get better grounding. I grounded my radio to one of those bolts that is right next to the vent where other items are grounded. Didn't take it directly to the battery. However, during troubleshooting I totally isolated the jeep and connected dummy wires to where they should go. Got the thing to work. Listened on some transmissions and am trying to figure out the sweet spot for the squelch. Heard someone just now who is about 30 miles away... didn't think these would pick up that far but transmissions tend to be better at night. When I was in the trouble shooting phase I had it on 19 and picked up truckers great, so I'll give it another whirl tomorrow. If I get some unruly static tomorrow I'm going to go draconian on the grounding.
 

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Sounds good.

30 miles is unusual, but possible (or someone is boosted). Don't count on it, though.

Grounding at a common ground CAN (not necessarily will) create a noisy situation. The best bet is direct power and ground to the battery (or PDC for +), but with a fuse in each line. You will probably be fine how ya are, though.

Under 2 = winning.
 

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Discussion Starter #14
Sounds good.

30 miles is unusual, but possible (or someone is boosted). Don't count on it, though.

Grounding at a common ground CAN (not necessarily will) create a noisy situation. The best bet is direct power and ground to the battery (or PDC for +), but with a fuse in each line. You will probably be fine how ya are, though.

Under 2 = winning.
Ah ok thanks... And the 30 mile figure was just a guess, he was talking about a town that is apprx. 30 miles away so he could have been between me and that location, just assumed. However, getting that ground to the battery isn't a problem, I just took it to the closest point I could. Took the hot directly to the battery though.

Whats so funny though, when I had the dummy wire directly to the grounded base and connected to the battery thats when I had my best SWR at around 1. I may need to try to rig something up like that. However if it works it works, don't feel like taking out the carpet again.. haha.
 

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Ah ok thanks... And the 30 mile figure was just a guess, he was talking about a town that is apprx. 30 miles away so he could have been between me and that location, just assumed. However, getting that ground to the battery isn't a problem, I just took it to the closest point I could. Took the hot directly to the battery though.

Whats so funny though, when I had the dummy wire directly to the grounded base and connected to the battery thats when I had my best SWR at around 1. I may need to try to rig something up like that. However if it works it works, don't feel like taking out the carpet again.. haha.
Yeah, power WILL give noise, ground usually doesn't - at least in my travels. At night, with the right conditions, 11m (CB) can 'skip' a very, very, long way, and boosting (unlawfully) does increase broadcast range, quite substantially in most cases. Your radio puts out <4W, imagine range on flat land at 100w. Again, this is not legal to do in the U.S.

If you're talking about a dummy load antenna, it should read 1:1, or VERY close to it, on a swr check. A long enough piece of wire will show perfect swr and not TX at all... swr testing (as done here) only measures reflected power. And it would take a very long wire, lol.
 
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