wilson 2000 swr difficulty

[cdj85]

Hello everyone, this is my first post on here. New to this stuff. I have been trying to get my swr down. I was able to mount a 5' firestik II on the F250 roof with a breedmount and get 1.1:1 but I can hear it vibrating and making alot of noise. I would prefer a more flexible antenna for the noise and when I'm out hunting in the mountains. I tried the wilson 2000 but I was only able to get it down to 1.55:1. I have a 203p linear on it and don't want any reflected power. What can I do to get the wilson antenna down lower? I do have a 10" shaft currently. I have the mount bonded to the roof in two spots. I have the hood bonded to the firewall and doors, cab, and bed bonded to the frame. I had about the same results (within 0.05:1) on a different truck's backrack with these two antennas as well. Would a longer shaft be better, and if so, how long?

 

[nomadradio]

The lowest SWR you can get on a particular antenna will vary from one to the next.

The 1.55 reading is perfectly okay, especially if this was as low as the adjustment would get it. The amplifier is fine with an impedance match of that quality.

Not wanting "any" reflected power will call for choosing an antenna that happens to bottom out at a lower level than this one. Won't bring about any performance improvement anyone can tell at the other end of the conversation.

73

 

[cdj85]

I was more worried about the amount of power being reflected back to the amp causing damage to it. I had about 3/4 watt coming back at one point. Just thought that may cause some issues down the road. It'll never be perfect with 0 watts, just trying to get it around what the firestik was showing. I had 16 watts out and not even .2 reflected with the FS2. I was wanting that with the wilson.

 

[nomadradio]

I was wanting that with the wilson.

Uh, why?

73

 

[cdj85]

Because of the noise and vibration of the firestik. I felt the wilson wasn't like that. And I feel lower reflection would be better for the long term of the amp.

 

[M0GVZ]

What can I do to get the wilson antenna down lower? I do have a 10" shaft currently. I have the mount bonded to the roof in two spots. I have the hood bonded to the firewall and doors, cab, and bed bonded to the frame. I had about the same results (within 0.05:1) on a different truck's backrack with these two antennas as well. Would a longer shaft be better, and if so, how long?

You want shorter, not longer. Out of the factory the whip lengths are made assuming a piss poor installation, typically a magmount thrown on the roof or trunk. The more efficient your RF ground the shorter the antenna needs to be for a given frequency. The problem when you've done a really good job and done some bonding like you have is that there's not enough adjustment in the whip to shorten it enough.

My car is bonded well, like yours. Every CB antenna I get is resonant around 25.5MHz to 26.0MHz out of the box and I typically have to cut a couple of inches off the whip to get it up to 27.5MHz where I want it. I do have to cut it though because the SWR is typically above 2.0:1. With a SWR of 1.55:1 I'd not even bother. A solid state amp will run fine up to a max of 1.6:1 to 1.8:1 depending on manufacturer.

I'm quite sure that if you had an antenna analyser so could check the SWR outside of the range of frequencies your CB will transmit on that you too would find the lowest SWR is below the CB band.

 

[cdj85]

I'll have to span out further on the test equipment and see what it looks like. I too had to cut a couple inches off the whip. So far nobody has seemed too concerned that this swr would cause problems with the amp so that has eased my mind a bit.

 

[hotrod]

I'll have to span out further on the test equipment and see what it looks like. I too had to cut a couple inches off the whip. So far nobody has seemed too concerned that this swr would cause problems with the amp so that has eased my mind a bit.

get a hold of a mfj 259b .. what channel do you mostly talk on ?? try tuning it to that exact channel.. whats swr on 1 and 40? you said ya trimmed it already may need a lil more ?? just dont over due it

 

[cdj85]

Channel 19 mostly. 1 got 1.6 on 1 and 40. 1.55 on 19. Used an anritsu sitemaster over the span of channels 1-40. I still want to span out more and see if its lower somewhere else outside the band.

 

[nomadradio]

Sitemaster is one heckuva tool. Should also tell you if the impedance is above or below 50 ohms. This would be the starting point to tweak anything further.

73