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Looking for guidence with new setup

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Rider On The Storm

Looking for guidence with new setup

#248590

Post by Rider On The Storm »

Hey all, Just looking for some help with figuring out some issues with my new setup.

I have 2 new co-phased Wilson T-5000 (5 1/2 feet apart)

I have very high SWR and before cutting my new antennas I decided to try some other things first.

The mounts are screwed into the bed rail closest to the cab (the no holes in roof method). The metal surfaces between mount and bed body panels are sanded to ensure a very good ground to the bed

SWR was like 3.5 all around. I did a continuity test all around and there were no shorts anywhere and the mounts were finding a ground.

Although very high SWR I was able to get out there 16+ miles. (testing with a buddy and a base station)

I was informed to ground the bed as it is a "floating" ground". So I worked up the courage to drill holes and with 0 gauge wiring I made more grounds for the battery (frame and body) Also grounding each bed body panel to the frame.

So only a couple hours later I do another contact with my base station bud and my TX was down.. alot, He could barely hear me anymore..

Am I still heading in the right direction with all the grounding even though my range when significantly down? Or should I go back a step?

I know one plaguing problem is my topper, But I don't have the heart to give it up.

I have a long ways to getting my SWR down to a resonable amount.. Starting with this.

Thanks guys.
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Rider On The Storm

Re: Looking for guidence with new setup

#248591

Post by Rider On The Storm »

Oh and I did forget to mention my SWR did go down close to a whole number all around after grounding.
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'Doc

Re: Looking for guidence with new setup

#248622

Post by 'Doc »

R.O.T.S.,
There are a couple things that could be done better. It's always better to have any antenna above metal than beside metal, so that being next to the cab or that topper is not a good idea.
That 5 1/2 feet separation between phased antennas isn't the best it could be. It will work, or be made to work, but it isn't exactly optimum.
There are several reasons why your SWR could be that high. I'm not going to get into that,just too many possibilities.
You can certainly make it work, but I think you'll find that a single antenna up higher will do just as good and probably better.
Good luck.
- 'Doc
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Rider On The Storm

Re: Looking for guidence with new setup

#248646

Post by Rider On The Storm »

The loaded coil is about 4in above the cab and then I have 49" whips. They stand up quite a ways and the cab sits pretty much under them. If I cant get the SWR to lower here I might move them.

But should I still keep grounding? It is lowering my SWR but hurting my performance for some reason.

And thanks for the Advice Doc, Ill have to do some testing with one or two. :)
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231

Re: Looking for guidence with new setup

#248655

Post by 231 »

I echo what Doc shared. First, a co-phased set up needs 1/4 wavelength (8' - 8.6' or so) spacing to work right. You don't have anything close to that. Sometimes they can literally fight each other. Maybe be the better the RF grounding you achieve, the more you are going to notice this? In any event, spacing matters...not to mention the canopy you have if it's metal.

What phasing harness did you get? 75ohm?

If it's the look you are after, lots of folks will run only one antenna using a piece of 50 ohm coax, not the phasing harness. I have always believed in a single antenna in a good location vs. cophasing. It can be very difficult to get the spacing correct...especially when your mounting location allows no variations.

Best of luck to ya'

:icon_e_wink:
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Rider On The Storm

Re: Looking for guidence with new setup

#248680

Post by Rider On The Storm »

Well after reading what you had to say, I have done some testing with different base station buddy's in an Open area and It seems the two co-phased are working quite a bit better than one with a single coax no matter which way I'm facing. I think I may have some radio performance issues aswell. The meter doesn't swing much with my voice, It shows a dead key almost the same as full voice, But I did put it on a watt meter and the Stock Cobra 29 puts out 6 1/2.

I think a lot of attempted talking before I knew what continuity or SWRs were caused some harm, heh.

I did invest in a Higher quality mic and that Improved my modulation over long distances.

I got a long way to go. My goal is to make sure my setup and brain are prepared for some good watts in the future.

And to be honest, I don't know the Ohms on my co-phase harness, I did not know their were different resistances in them. I grabbed the only harness I saw and that was a "Barjan RG59 A/U Co-phase Harness" There is only one place around me to get anything CB Related within 60 miles and thats a truck stop.

Should I invest in another harness?

Ive had someone try to talk me into letting them crack open my radio and do some tuning, but I wouldnt know if the radio is worth it (Cobra 29nwst)
Someone is also trying to sell me a pre peaked and tuned Cobra LTD for $20 but At that price I imagine something is wrong.

Thanks guys, your giving me a good start on my first good set up.
Appreciate it.
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'Doc

Re: Looking for guidence with new setup

#248739

Post by 'Doc »

The only part of that I'll comment on is the impedance of the co-phasing harness. 75 Ohms is what's needed, and you have that with RG-59 coax. You can't do co-phasing with the same impedance coax as being used with the rest of the system, which is normally 50 ohms.
- 'Doc
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PONY EXPRESS
Wordwide & Qualified
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Re: Looking for guidence with new setup

#248798

Post by PONY EXPRESS »

Myself we adjust antennas individually 1st before hooking up phasing lines .. thats the proper way to do it .......
Others will say just adjust them back and forth to get a low swr ............
But again I might not know what we are talking about :biggrin: :biggrin: Stacked 1296 MHZ 35 elements antennas @ 5 ft off the ground
If you hook up phasing lines 1st you have No Idea the actual SWR of both antennas .
So my suggestion is run a known good 50 ohn rg58 rg 8x or rg8 coax to 1 antenna adjust it for low swr and then the other before running that phasing line.

Spacing is another major issue as 5 1/2 feet is not nearly enough as others have already mentioned.

Read the very bottom section on how to do co phased antennas on this link......

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Last edited by PONY EXPRESS on Sep 29 2009, 10:52, edited 2 times in total.
Its not a real radio unless it has tubes and USB/LSB on the front panel ....
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MoJo

Re: Looking for guidence with new setup

#248802

Post by MoJo »

As for your performance issues you may have smoked your radio while testing with that high SWR.

Like PE said in a cophased system use 50 ohm coax and tune one antenna at a time then put your 75 ohm harness back in.
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alhefner
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Re: Looking for guidence with new setup

#248809

Post by alhefner »

Matching dual antennas can really look a lot better than a single BUT just like others have said, if you don't have at least 8' between them, then co-phasing is not the way to go. If the look is important to you, simply run 50 ohm coax to one antenna and tune it for best SWR leaving the other antenna as a dummy simply for the look of it.
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Rider On The Storm

Re: Looking for guidence with new setup

#249021

Post by Rider On The Storm »

It was all in my radio.
Just came home with a Galaxy dx99v with 2 1969 finals, strapped and she sure screams
Its an oldie, But this guy took dang good care of it, Looks out of the box!

I couldnt be happier, 2 hours later and Im in love with the radio.

on top of that, after some tuning I got to 1.3 swr, just had a 4 pound conversation with someone 26 miles away!
haha!

It has something else too, Im not quite too sure what its called. Theres a switch on the side that he was referring too as "ears", I think its like a preamp but dang it really pulls them distant people in close.

I got compliments the whole way home on how good my audio was.

Got the radio, 2 mics, and an external speaker for $200!

Mojo, This is because of you I hope you know!

Thanks guys :)
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tailgate
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Re: Looking for guidence with new setup

#271757

Post by tailgate »

i have connex 3300 hp im geting a dave made 400 mobile 4pill 4x2879 transistor amp powerd at 15v dead key 400w/peak800. 20v dead key 800w/peak1600w.what do i have to do to get 20v to amp step by step.all i done in the past was run my amp stright off battery.they did tell me this dave made amp im geting will need a driver. thanks for all the info.will this amp put out this kind of power at 20v
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