anybody on here run a high power (3kw+) suburban? i need some advice

[groundwire]

i have tried everything and i just cant get my reflect down. 1.6 lowest swr on all antennas i try. im almost fed up already. its driving me nuts and my amps. i have 2 predator 10k antennas 17" shaft and 2 55 r4 antennas as well. they both tune the same, 1.6, i gotta get 1.3 swr or better. my reflect is waaaay to high and im gonna burn up my amps. not good. how did you and the other guys do it at 3kw plus? i have puck mounts, lmr-600 coax, jumpers are 6ft,antenna coax is electrical 1/2 wave (from line section to antenna). 1" ground strap bonded doors, hood, body, frame etc. im out of ideas. also the fact that two different antennas are tuning exactly the same at 1.6 is making me think something else is going on.
i want to concentrate on getting just the one antenna only too tune flat (which is how i drive around), then i will concentrate on tuning the bounceback setup (used when i park shootin skip).

[JesseJamesDallas]

Which antenna are you trying to get tuned for "drive-around"....If it's the middle one, you can forget about getting a low SWR on the Burb...

Your set-up sounds allot like mine did when I had my Suburban...I had it set-up so I could run either 2-hots, or bounce-back, or just one...As much as I tried to tune just one antenna in the middle of the roof, I never could do better than 1.5 to 1.8 SWR with my Predators. (I also use the 17" shaft...12" don't tune worth a flip)

The Back antenna, using a Predator 10K with the 17" shaft, mounted about 6" from the back, "should" tune flat as a pancake...The Fatboy R4 should also tune low on the back, but maybe not as low as the Predator...

I've have used the Predator 10K's, 30K's,(regular single coil, bad to the bone-coil, Comp.-coil,and all the different shafts) Fatboy R4's and the R6...55's, Monkey Made "Big John", and even a Wilson 5000 on the back of the Burb, but always had the best luck with the Original Single Coil Predator 10K with the 17" shaft.

This was when I was running a DM 16 pill



Lost all my other pics of the Burb thanks to a computer melt-down a few years ago

[groundwire]

Which antenna are you trying to get tuned for "drive-around"....If it's the middle one, you can forget about getting a low SWR on the Burb...

Your set-up sounds allot like mine did when I had my Suburban...I had it set-up so I could run either 2-hots, or bounce-back, or just one...As much as I tried to tune just one antenna in the middle of the roof, I never could do better than 1.5 to 1.8 SWR with my Predators. (I also use the 17" shaft...12" don't tune worth a flip)

The Back antenna, using a Predator 10K with the 17" shaft, mounted about 6" from the back, "should" tune flat as a pancake...The Fatboy R4 should also tune low on the back, but maybe not as low as the Predator...

I've have used the Predator 10K's, 30K's,(regular single coil, bad to the bone-coil, Comp.-coil,and all the different shafts) Fatboy R4's and the R6...55's, Monkey Made "Big John", and even a Wilson 5000 on the back of the Burb, but always had the best luck with the Original Single Coil Predator 10K with the 17" shaft.

This was when I was running a DM 16 pill



Lost all my other pics of the Burb thanks to a computer melt-down a few years ago

yea, im trying to get the front one tuned in for ride around. i had a couple other people say that too. run it in the back, the middle wont tune. i will try it. but, what about when i run the bounceback setup? the swr's are 1.5 lowest i can get. because the front wont tune low. i think something i am not seeing is the cause. i dont know. as the power goes up the reflect goes up

[whiteastro]

I'm not as experienced with this as some of you guys so don't beat me up too bad but I was wondering when you run a system like this do you have to run 75 ohm coax because of 2 antennas?

[JesseJamesDallas]

no on the 75ohm coax, thats used for a co-phase set up with two antennas.

as for the back reflector antenna, it needs to be about 6" taller than the front...and 72" spacing between the two .
you may have to play with the height of the back antenna some, but the set up should tune lower...

are you using a antenna analyzer on this?

[whiteastro]

no on the 75ohm coax, thats used for a co-phase set up with two antennas.

as for the back reflector antenna, it needs to be about 6" taller than the front...and 72" spacing between the two .
you may have to play with the height of the back antenna some, but the set up should tune lower...

are you using a antenna analyzer on this?

Thanks JJD I have to laugh because I still have a lot to learn on this stuff!

[groundwire]

no on the 75ohm coax, thats used for a co-phase set up with two antennas.

as for the back reflector antenna, it needs to be about 6" taller than the front...and 72" spacing between the two .
you may have to play with the height of the back antenna some, but the set up should tune lower...

are you using a antenna analyzer on this?

yes, i am using a rigexpert aa-55 analyzer.

[JesseJamesDallas]

yes, i am using a rigexpert aa-55 analyzer.

Good...I was going to suggest getting one if your going to be doing these kinds of set-ups.

Just make sure you get the back antenna grounded-out good, and start with it at least 6" taller than the front antenna...You may want to first tune the front antenna best you can without the back antenna on...Then once you get the front tuned best you can, then put on the back antenna, with the stinger at least 6" higher than the front...Then check SWR again and see what happens...

Next try adjusting the stinger on the back antenna up, or down, and check SWR each time to see if it drops...

then next try adjusting the front antenna again and check SWR each time...

It's a pain! but you should be able to get lower than 1.6 with those Predators.

[groundwire]

yea it is nuts. up down up down up down lol, crazy. easier with two people. wish i had someone to help me. oh well.....

[groundwire]

well i tried the new 27" predators, swr went down a little but still to high. from 1.67 to 1.48, this sucks already. something really weird i saw is when i park next to these pine trees by my place or next to the big metal roll door on the shed the swr goes down to 1.05. wtf? im going nuts i swear lol