Where/how do you have your CB mounted in your TJ?

[DAA]

Okay, next question...

Does it really matter how long the antenna cable is?

I went with the overhead mount. Which means moving my antenna cable from where the junction box of the 75 was mounted in the console near the shifter and routing up to the header. As my antenna is mounted now, I'm coming up about 1 - 1.5 feet short on the cable.

I can get that extra length by moving the antenna from my swingout and getting one of those tail light mounts. But it would be a lot easier and cheaper to leave the antenna mounted where it is and just get a short patch cable exactly like the one I use with my SWR meter to add another 12" or 18" to the cable.

A quick Google turned up totally conflicting opinions. Is having a cable exactly 18' long really that important? Does it actually even matter at all? Will the SWR meter tell me one way or another?

Tempted to just pick up the patch cable and finish the install and see what my SWR is. If that's good - the install is good, right?

Thanks!

- DAA

 

[frieed]

DAA,

cable length = 18' is critical IF you are using an antenna specifically designed to not need a ground plane like some of the ones they sell for RV's. This is because the cable is part of a resonant circuit that feeds the antenna. If you are using something like the Firestik I have or almost every antenna sold, it assumes a ground plane and the length of the feed cable is not critical. More important for these types of antenna are the uniformity of sheet metal around the antenna that acts as the ground plane. If the ground plane is not uniform (read nearly every installation where the antenna is not in the middle of the hood or metal roof) then the radiation/reception pattern becomes directional in the direction of the metal. Bottom line, SWR will tell you what you need to know. I installed a 3' Firestik on a bracket that mounts about a foot in front of the driver on the gap in the hood on my JKU. SWR on ch1 and ch40 is 1.6, on ch19 is 1.0

Of specific note on any antenna that has a tuning screw with a plastic cap over it: the cap changes the tuning, so move the screw and replace the cap before checking the SWR

-Frieed

 

[STAG]

I think an eighteen foot antenna would hit snap off on overpasses. Could be wrong.

 

[Hickey]

3' increments is what is important. Try a patch and see what the swr says.

 

[DAA]

Thanks guys - very helpful! A patch cord it shall be.

- DAA

 

[DAA]

Well, crap...

I'm having big time problems with this install. Something is very definitely rotten in Denmark...

Finished up the install, hooked up my SWR meter, turned on the new radio and got SWR readings over 3 on both CH1 and CH40. Basically pegged the meter. Not good. Turned it to CH19 and did pick up some faint chatter from either I-15 or maybe Legacy. After checking CH19 for a minute I just shut it down. Note, at this point, the radio has only been keyed twice each on the two channels for a couple of seconds to calibrate the meter and take SWR readings. Even with the high SWR I don't think I could have damaged the radio just keying it a couple times for a few seconds?

Googled for troubleshooting steps and found some good stuff at Right Channel Radios.

First step, checked continuity between the mount and the battery to verify the mount has a good ground - it does, meter reading of .003 between the mount on my swing out and the battery negative terminal.

Then I started checking some other continuity points according to this page from Firestik:

Immediately found an apparent problem. There was continuity (reading of .000, no resistance) between the upper part of the stud (where the antenna screws in) and the mount. According to the graphic above, there shouldn't be. Indicating a short somewhere.

So, I started checking other things, just trying to narrow the search down. What I checked:

- The antenna itself checks out okay with continuity between the tip and the threads.
- From the tip of the antenna to the "hot tip" of the cable that plugs into the radio shows continuity, as should be.
- Between the hot tip and the threaded connector barrel at the end of the cable that plugs into the radio shows no continiuty (infinite resistance/open circuit), as should be.
- Between the mount and the connector barrel at the radio end of the cable shows continuity (good ground), as should be.

I decided to check the patch cord between the SWR meter and the radio. It checked out fine, continuity between ends on ground-to-ground and hot-to-hot but no continuity between ground and hot.

Here's where things start to get confusing/strange/ugly.

Next I put the patch cable back on the radio BUT NOT ON THE SWR METER. So the patch cable was just hanging free from the radio. The radio has power to it but is not turned on. Checking the end of the cable for continuity between the hot tip and the threaded barrel SHOWED SOME CONTINUITY. A reading of .779 to be exact. Now, I'm really not sure what it should be, but I'd have expected no continuity?

So, at this point, the antenna cable is just hanging free, not plugged into the SWR meter or the radio. For some reason I decided to check between the mount and the stud again and this time it read no continuity just like it is supposed to. WTF?

Plugged in JUST THE SWR METER to the end of the antenna cable, but did not connect the meter to the radio. Now the reading between the stud and the mount is still no continuity again, as it should be.

Plugged the antenna cable directly into the radio, no SWR meter, and the continuity between the stud and the mount reads .779, the same as the end of the patch cable connected to the radio.

Okay, this is getting awfully confusing to me. But I think that there shouldn't be any continuity between the stud and the mount in any condition, but that isn't what I'm seeing and it's the only thing I've checked/tested that I can point to as a problem. Here are the continuity readings between the stud and the mount summarized:

With the antenna cable not plugged into anything - no continuity between stud and mount (1 on meter), as it should be
With SWR meter inline between cable and radio - full continuity between stud and mount (.000 on meter), NOT as it should be
With just SWR meter on the end of the antenna - no continuity between stud and mount (1 on meter), as it should be
With the cable plugged straight in to the radio w/out SWR meter - some continuity, .779 on the meter - the same reading a patch cable coming out the back of the radio reads

One last thing - I have a K30 magnetic mount antenna so I tried it too. It doesn't peg the SWR meter as bad as my permanent mount antenna, but still has SWR of well over 3 on both CH1 and CH40.

So, what in the wide world does this all mean?? I've less than a clue. I don't know what else to check. Everything I read says ground, ground, ground, but all my grounds check out good on the meter. At this point, I'm wanting to say I got a bad radio maybe?

Any advice on where to look next would be greatly appreciated!

- DAA

 

[DAA]

Just want to try and maybe be more clear, less confusing about the continuity between the stud and the mount. So, I marked up this image a little bit.

To be clear, I'm testing continuity between the two black circles I added to the image on the furthest right stud mount above.

According to the diagram, there should be NO CONTINIUTY between the stud and the mount. But, I am measuring continuity there. But only when the antenna cable is plugged in to the radio. To be even more specific, with the antenna cable plugged directly into the radio I'm getting .779 continuity on the meter. With the SWR meter inline I'm getting a full .000 to .003 continuity - zero resistance.

Now, to further add to the confusion... All of that was with power connected to the radio, but the radio turned off. After my last post I triple checked it again and got the same readings, then tried it with the radio turned on and got no change.

BUT! When I disconnected power from the radio, there WAS a change.

With no power to the radio and the antenna cable plugged directly in to it, I'm getting a "normal" no continuity reading between the stud and the mount - 1 on the meter. But with the SWR meter inline, I'm still seeing .000 to .003 - full continuity.

The SWR meter appears to be working, but, hell if I know...

Still, basically the only clue I have at this point, is that there should be no continuity between the stud and the mount, but with the radio plugged in and power connected to it, it DOES show some continuity - .779. That, in itself seems an indication of a problem that only shows when the radio is plugged in. Wondering why adding the SWR meter inline takes it from .779 resistance on the meter to .000 is only making my head hurt worse.

Am I making sense in explaining what I see going on? If so, does what is going on make any sense to anyone?

Ughh...

- DAA

 

[frieed]

DAA

Measuring for shorts in the cable and antenna mount can't be done with the cable on the radio. The output of the radio is an active circuit and will not read as open or hi impedance, and yes power on vs power off will make a difference. Are you sure that you are using the SWR meter correctly? You set it to FWD, key the mic and adjust the knob to set the needle to the REF mark, then switch to REF/SWR and read the SWR all while keying the mic.
Is your antenna adjustable? Maybe it's adjusted so far out that the SWR is off on all channels. If the cable/mount/antenna show no shorts, the antenna length could be the issue or even defective radio. When you tried the mag mount antenna, did you use just the cable that came with the antenna, or did you tie into the existing cable you have been testing? If you want to swing by, I'd be glad to lend a hand. I have another SWR meter and another radio we can try.

-Frieed

 

[DAA]

Measuring for shorts in the cable and antenna mount can't be done with the cable on the radio. The output of the radio is an active circuit and will not read as open or hi impedance, and yes power on vs power off will make a difference.

Well, that's good news, I think? Everything is checking out good on the meter with the cable not connected to the radio. Just to be clear though, having the radio turned on or off made no difference - having power connected to the radio made a difference. No power connected = normal, power connected = continuity between stud and mount.

Are you sure that you are using the SWR meter correctly?

99% sure I'm using it correctly. Have used it several times before and had success.

Is your antenna adjustable? Maybe it's adjusted so far out that the SWR is off on all channels. If the cable/mount/antenna show no shorts, the antenna length could be the issue or even defective radio. When you tried the mag mount antenna, did you use just the cable that came with the antenna, or did you tie into the existing cable you have been testing? If you want to swing by, I'd be glad to lend a hand. I have another SWR meter and another radio we can try.

The antenna is adjustable, it's a Wilson Silver Load 4'. But I haven't yet tried adjusting it, it is still where I had it adjusted for my old radio (Cobra 75, SWR was ~1.5 on both 1 and 40). With the SWR as high as it is now on both channels, I figured I must have a bigger fish to fry somewhere than length adjustment. With the mag mount I did use the cable that came with it and it DID show better SWR - but still terrible, over 3 on both CH1 and CH40.

Another radio and SWR meter would be great to quickly and definitively rule out whether mine are bad or not. Wish you were closer! What is your schedule like tomorrow or this weekend?

And Thanks!

- DAA

 

[frieed]

Tomorrow is busy, but the weekend is open. Sorry about the geography. PM me and we'll work it out

-Frieed

 

[Hickey]

I'm available today if ya wanna drive out. I have several different antennae and radios we can swap out.

Make sure your mic gain is all the way down while checking SWR's, it can throw off the readings. Don't worry about causing damage by just keying up for SWR checks, just keep it brief and don't speak or whistle in the mic while doing so.

High SWR'S cause damage because they generate higher levels of heat in your final transistors. The higher the SWR's, the more heat produced. Heat will degrade any electrical component, it's just a matter of how much heat, and how long that component is exposed to it. Any time you transmit, you send power through those finals, thus generating heat.

In short, you can listen all day long to a radio with high SWR'S and cause no damage. If you deliver a 5 minutes speech, you will dramatically shorten the life of the finals if you have high SWR'S.

 

[DAA]

Huh-hmmm... I've had the mic gain all the way up the whole time.

I might be able to drive out there this afternoon - I'll shoot you a PM. This is the kind of thing that will drive me crazy until I get it figured out.

Thanks!

- DAA

 

[DAA]

Little update...

Hickey was kind enough to spend a couple hours with me working on this today. We learned a couple of things, useful things, but, as of now, it still isn't working and if anything the reason is even less clear.

The radio is good, at least. We know that. My mag mount antenna works, or at least it can work, we know that. But neither one of them will work in my Jeep!

We tried several different antennas. We tried a different radio. We tried a new antenna cable. We tried a new stud mount. Nothing we tried would make a radio work when in my Jeep. Well, not transmit with acceptable/safe SWR anyway - it recieves really well.

It's just plain strange. An example. We know the radio is okay because when we put my mag mount antenna on the roof of his wifes Grand Cherokee and hooked my radio up to it, we got a flat 1 SWR on CH1 and a SWR of 3 on CH40. An acceptable range from which to tune an antenna. Put the radio back in my Jeep and put the mag mount antenna on the hood and SWR's are pegging.

Another strangeness. Hickey had a brand new terminal type stud mount and cable. So we hooked them up. No joy. But being as the stud mount was terminal type, the ground was right there easy accessible. Put a jumper wire on it and tried straight grounding to various points, didn't do much. But then I started to touch the ground jumper to my aluminum fuel tank. Just BEFORE the ground wire touched the tank, the SWR would drop to 2, but as soon as it actually TOUCHED the tank, it would jump back up to 3. In other words - when the ground wire was still in the air and touching nothing, the SWR would drop all the way down to 2, but as soon as it actuallly touched something grounded to the chassis, SWR would peg again. Strangeness...

Best I can guess, is there is some sort of strange voodoo-bad-ju-ju force field or something radiating from my Jeep that renders CB equipment useless.

But the radio works, and my SWR meter appears to be working too. I was going to go coyote hunting tomorrow, but this is just bugging the crap out of me. I'll probably stay home and dick with it some more.

- DAA

 

[frieed]

Time to call for an exorcism...

When It worked on the Cherokee, was it powered by the Cherokee?
When you moved it back to your jeep, where did you tap the power?
I'd try a direct connect to the battery terminals with no other wiring involved.
Then move either power or ground to the intended connection point, then the
other leg. If It works on just the battery, the there is no curse on the jeep,
however, there may be poltergeists to deal with within one or more subsystems...

 

[DAA]

For power, we used a 12V outlet adapter that Hickey has. We had to, because his Galaxy blew the fuse on my radio power plug . So, all testing from there out was from the factory power outlet in the dash. But yes - when it worked in the GC it was powered by the GC. When it wouldn't work in my Jeep it was powered by my Jeep.

I actually can't remember where I have the radio power plug getting juice from. This new radio is replacing my old Cobra 75 and all I did for power was snip off the 75 pigtail and splice onto those two wires and route them to the new overhead location. I originally wired that 75 like 6 years ago and honestly just don't remember from where. It would have been as close to straight off the battery as I could get it though. Heck, it might actually be straight off the battery.

Good avenue to pursue though. I'll hit the Flying J later today for another power plug that I can try right from the battery as suggested. See what happens. Maybe make a 12V adapter to try powering the radio from another vehicle or my powerpack. Even though the mount ground tests out great on the meter, I was thinking of taking a jumper cable and clamping it straight from the battery negative terminal to the mount just to be stupid sure about that too. Just throwing darts and grasping at straws. But I cancelled coyote hunting today over this radio - I'm going to kick it's azz one way or another!

- DAA

 

[frieed]

Here is how I mounted a 36" Firestick II on my 2012 JK



Bent a piece of Simpson Strong tie stuff from home Despot to fit the curve of the hood/fender
and used an existing fender mounting screw with several layers of electrical tape underneath
to protect the paint



Added extra groundy goodness to existing ground point



With this arrangement I get SWR of 1.6 on both ch1 and ch40
with SWR of 1.0 on ch19.

It needs a spring, since smacking branches while wheeling will bend the mount, but so far I just bend it back.

-Frieed

 

[Hickey]

My opinion is, there is an accessory somewhere on the Jeep causing a dead short. After trying multiple combinations of components on Dave's Jeep, I think there is an electrical problem interfering with anything grounded to the Jeep. We experienced almost no change in SWR'S regardless of the different components we switched out.

My suggestion now is to remove the vehicles pos and neg cables at the battery. This should cut power to everything on the chassis. Next, using your power pack or a second battery, hook power and ground to the cb, and ground the battery to the Jeep. That should completely isolate your CB from any electrical problems existing on the chassis. If this doesn't give you different readings, then I'm totally at a loss.

 

[DAA]

The Saga Finally Concludes!

Well, it's finally whipped. Yippee!

I tried absolutely everything I could possibly think of yesterday. Including re-doing everything I had already tried. I tried my radio and antenna in Grimmjpr's JK and his radio in my Jeep. I redid all the multi meter testing, twice. I also did almost exactly what Hickey recommends above - using a power pack and then later a jumper cable from a negative battery post and what not to take my Jeeps electrical system out of the equation.

By the time all was said and done yesterday, I was positive the radio and my antenna were both fine - they worked great in Steve's Jeep. I started the day really thinking it was some weird electrical voodoo going on with my Jeep. But the powerpack and battery disconnect testing changed my mind - it still wasn't working even when taking my Jeeps electrical system out of the equation.

One remaining possiblity was antenna placement. Placement with my mag mount K30 was making big differences. But testing placement with my 4' Wilson would involve new mounts and really a new cable and stud too since the way I had my old one installed and routed meant a fairly major project to take it out. I figured if I went to that much trouble, I'd just replace them with new cable and stud just on GP. I kind of doubted placement was really it anyway though, I've been doing fine with that same placement for years with my old radio.

If it wasn't antenna placement, really all that was left was either the cable or the stud mount. I did not think it could be though, for two reasons. One, I had tested those components with a multi meter like ten times and they all checked out just fine according to the testing instructions I was going by. And even more than that, Hickey and I had already tried brand new out the package cables and stud mounts the night before and it hadn't made any difference. I was really pretty sure that it COULDN'T be my cable and stud.

So, those were my possiblities and I had good reasons for not really thinking it could be any of them. But I decided just to go buy a new cable and stud mount. I figured if that didn't do it, I could at least put them to use trying different antenna placements around the Jeep.

Well... I'll be go to hell... Just a new cable and a new stud worked like a champ! I just spent only a couple of minutes messing around with antenna length and SWR's right now are 1.2 on CH1, 1.4 on CH20 and 1.8 on CH40. I won't bother trying to tune it anymore until after I pud the hard top on later today, but I could live with it just like that.

I really can't believe how hard this was! And frankly, even now that it's fixed and working, a lot of what I saw in trying to figure it out still doesn't make any sense. Like, what finally cured it was a new cable and stud, but I had already TRIED THAT and it hadn't worked the first time? Lots of other total strangeness along the way.

But a million thanks to Hickey, Frieed and Grimmjpr! You guys all spent your valuable time and effort and really helped me finally get this thing put to bed and I REALLY appreciate it.

- DAA

 

[DAA]

Here is how I mounted a 36" Firestick II on my 2012 JK



View attachment 76431

Added extra groundy goodness to existing ground point

I took a look at this last night and was thinking about trying something like it on my TJ. But the fender is different on the TJ. To use existing bolts really wouldn't be feasible - it would require a 180 degree bend in the mount, followed 1/2" later by a 90 degree and just wouldn't be very rigid anyway because of the configuration. Really, the only way to mount there on the TJ is to use flat stock and drill holes in the fender. Which, I really didn't want to do except as a last resort.

Turns out I'm getting performance I can accept with the antenna on my swingout though, of which I'm glad.

- DAA

 

[Grimmjpr]

Glad to help......glad to see it was just the stud and cable......it was doing crazy stuff......yay working CB......