New Predator 10K installed

[Aughtry]

Ok, so I installed my new Predator 10K today. I have everything grounded. Hood, cab, bed, and mount are all grounded to the frame.

Galaxy DX959 - 3ft coax to Palomar 250 - 3ft coax to SWR meter - 12ft coax (from G.I.Joe) to the antenna mount. This setup had 1.3 on both 1 and 40 with the Wilson 1000 magnetic I took off. I am now using a metal mount that is bolted to the bed, and has a ground wire going from it directly to the frame. The base of the Predator is 3 inches above the cab of my truck, and about 3 inches behind it.

When I started I had 2 on 1 and 3 on 40. After incrementally cutting off about 5 inches I am down to 1.7 on both 1 and 40. The predator, as many may know, has about 4 inches of whip inside the top tube. I started with the whip all the way at the bottom. I cut incrementally keeping it at the bottom until 1 was just higher than 40, then pulled the whip (part of that 4 inches) up just a bit to get them both the same.

I have read that running a stock radio at 1.7 is no problem, but what about with that Palomar 250? I don't want to turn it on and lose a Galaxy. What details can I look at to lower the SWR? Would 18ft work better than 12ft, or no real difference. I honestly don't see what else I could do to the grounding except maybe grinding the corrosion off of the bottom of the bracket where it meets the antenna mount. BTW, a grinder was used to get to bare metal on all grounding points except this spot.

I may have just answered my own question, but...

Tips and Tricks pleas???????

Once working properly, and I get the back glass of my truck replaced (broke it today), I'll post pics of the setup. Provided I'm allowed to yet.

[sonoma]

the lower portion of your antenna may be just close enough to the cab to be causing some reflect on you. I think you said it was 3 inches from the cab. I run mine behind the cab also and depending on what antenna I run it goes up and down also. do your clean up and see what happens. I also put star washers between the mount and bed to help with the grounding. gives it a good solid ground also.

[jessejamesdallas]

I agree with sonoma, Too close to the cab and the 10K's won't tune....Probably would tune just fine if you had it in the same place you had the Wilson.

Another thing, you didn't say which lower shaft you had. (12",17",22",27") If you have the 12" lower shaft, just by going to the 17" would help lower the SWR. (you would end up having to do some more trimming)

[sonoma]

The base of the Predator is 3 inches above the cab of my truck, and about 3 inches behind it.

this is what you said about the base of the antenna is located. is this the base or the coil. if it is the base which would be the actual mount location you should be able to tune it, but I am thinking this is the coil which is really to close to the cab along with the shaft that JJD mentioned. the coil if that is what you mean is rather close to the cab.

[Aughtry]

Thanks folks! The base of the coil is 3 inches above the cab on the 9 inch lower shaft. If getting the 12 inch will help, I'll get it and try again. It's considerably shorter than the Wilson was. Adding 3 inches it will still be about an inch less than the Wilson.

Appreciate the assistance.

[Aughtry]

Here's a pic from the side of my antenna placement. On my previous truck it was mounted to the tool box and level with the roof. Now it's a bit lower because the toolbox doesn't fit this truck with the wheel well placement being closer to the front.

Well I was going to, but Preview says I can't post pics yet.

I don't see pricing for just the 12 inch lower tube on G.I.Joe's site, but I'll contact them. I was also thinking about the following part from G.I.Joe's if moving the antenna back a few inches will improve it.

Can't link yet either.

[The DB]

Thanks folks! The base of the coil is 3 inches above the cab on the 9 inch lower shaft. If getting the 12 inch will help, I'll get it and try again. It's considerably shorter than the Wilson was. Adding 3 inches it will still be about an inch less than the Wilson.

Appreciate the assistance.

When you add the longer lower shaft you will have to shorten the overall length to compensate. The overall antenna length will be slightly longer, but not three inches longer.


The DB

[sonoma]

you might look at a quick discannect that is about 4 inches long will raise the antenna some. I have one on my antenna and it help some on my swr. there is 2 different disconnects out. one is only about 1 inch long and the other is about 3 inches long. just some thing to think about. might even be a lot cheaper.

I sent you a PM of the one I am talking about. hope you can get PM's now.

[Aughtry]

I can't yet, but I googled it. Think I found both of what you were talking about. Thanks.

[jessejamesdallas]

Thanks folks! The base of the coil is 3 inches above the cab on the 9 inch lower shaft. If getting the 12 inch will help, I'll get it and try again. It's considerably shorter than the Wilson was. Adding 3 inches it will still be about an inch less than the Wilson.

Appreciate the assistance.

If your going to get a longer shaft...Get the 17"...Bigger difference between the 12 and 17" when tuning....and like DB pointed out, you'll need to do some more trimming on the stinger to get the over-all height back down close to where it was with the 9" shaft.

IF GI Joes doesn't sell the replacement parts for the Predators, just Google Predator 10K Antenna...

[Aughtry]

OK, so in my impatience I went by my storage facility to find a bag of goodies. Two 3ft pieces of coax and an 18ft piece that I had a somewhat local shop make for my previous truck, and a HEAVY DUTY spring.

I triple checked my grounding and decided to add another strap from the back of the cab to the same grounding point on the frame as the antenna mount. The cab already has a ground strap on the front, but what the heck. Replaced all the coax (the previous 3footers were store bought) and added the spring.

I now have 1.3 on 1 - 1.4 on 40 - and 1.3 on 20 I'm hoping I can run it like that until either I get the 17 inch lower shaft for the Predator, or take the mount back to the fab shop that made it to have some length added to make it roof height.

I appreciate all of the responses. It helped me get into the right mindset as I return to running a proper radio in the truck. Sometimes just talking about it can jog your memory, or let loose that brain F@rt.

[sonoma]

swr looks good now. glad you were able to figure it out.

[Aughtry]

New question. I tuned everything with Radio - amp - swr meter - antenna, with the amp inline but off. When I key the swr meter shows 1.3 but my radio's swr warning light come on, and it's display shows over 3. Should this concern me? If so, how do I fix it? At this point I'm very concerned.

[jessejamesdallas]

What is the radio's dk set at? If it's set lower than 3w's, that happens sometimes on some radios...I had a Cobra 29lx that when I went to the diagnostic settings to check SWR I would always get "ANTENNA FAIL" because I had the dk set down to just 1 1/2w....

As long as the external SWR meter is reading right, I wouldn't worry about it.

[Aughtry]

It's variable, but set at 2 for all of this.

-- Friday, 03 February 2017, 19:04 PM --

I purchased the radio from G.I. Joe's a few years ago. Had the peak and tun, and modulation mod done.

[MDYoungblood]

I'd take the amp out of line and use a barrel connector on the coax, see what the SWR is that way, could be an impedance mismatch at the amp.

3's

Greg

[Aughtry]

I did like you suggested and put a barrel in place of the amp. The warning light did not come on. The radio showed 1.1 while my meter showed 1.3 So my antenna is tuned in.

Is that impedance mismatch going to be a problem? If so, how do I go about correcting it? I have no problem with getting into the amp.

[MDYoungblood]

I'd make a topic about the mismatch and let the guys with experience jump in. You can try different length coax between the radio and amp but that is just a bandaid on the problem.

3's

Greg

[Aughtry]

With a little further investigation it seems that the false red SWR indicator is a known issue. Supposedly replacing C5 on the SWR PCB with a 1/4 watt 22K resistor solves the issue.

Sent from my SAMSUNG-SM-N920A using Tapatalk

-- Wednesday, 08 February 2017, 21:25 PM --

Eureka! Problems solved!

I REALLY did not want to take my mount off of my truck because of how much a pain in the butt is was to get it on there, but I defeated that lazy impulse. Took it back to the fab shop that made it for me, and had 8" added to the height to fit it to my current truck. I should have done that to begin with.

I reconfigured my grounding scheme. I know larger gauge wire would be better, but a #10 is what I have in abundance. Ran some from bare metal contact points on the hood, cab, bed, and mount, to the same point on the frame.



Now to the mount. If you can see the two tie-wraps, that's also where the welds are, and the length added. Before this the 5" spring and 3" of the shaft were below the roof. Apparently that was causing problems.



Now my SWR is 1.3 across the board, and the red SWR Warning light on my Galaxy doesn't come on. Actually the radio meter shows the same as my inline meter now.

Now I need to get on the air while folks are talking to get some reports.

I do, however, have the 17" lower shaft coming in the mail. I like the idea of having the spring in place to take a hit, but I will put it on to see if I can get the SWR lower. Take out the 5" spring and and the 9" shaft, put in the 17", it will be a bit higher, but maybe better performance without the spring.