Got my tower up!

[Tinman590]

I finnaly got my tower up with a new imax on the top of it. Im about 65 feet to the tip of the antenna. My swr is 1.2 on 40 and 1.8 on channel 1, does anyone think I should adjust it more? The tower was a pain to get up there, I could climb it but thats not on the top of my list. Just looking fo opinions

[Tinman590]

no opinions?

[linx]

I'd adjust more. How bout some pics?

[PONY EXPRESS]

I would not be happy at all with that High SWR on channel 1... Try changing those adjustment rings like instructions say

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This picture photo 2 gives approximate where those rings should be located for tuning.
My IMAX 2000 is 1.1-1 all the way across channel 1 - 40 so something is needing adjustment.

[preacherman]

I'd say it depends on where you plan on spending most of your time frequency wise.
Preacherman

[tj1]

My Imax needed adjustment also...made a big difference ended up turning the tuning rings about 4 turns clockwise... ended up with swr on channel 20 1.1 and nothing higher than 1.2 on any channels.

[Texas Mobil 219]

I would say that its telling you its short. Allittle more tuning and i bet it come in at 1.1 or better.

[Tinman590]

I dread climbing that thinor so.g but I guess I will do it, I want to get it on down some so I will let yall know how it goes. Linx I will get some pic here in a day or so.

['Doc]

If HE had wanted me to get that far off the ground, HE would have made my legs longer! Don't blame you about climbing towers. Maybe you could find some idio..... helpful soul to climb it for you??
- 'Doc

[721HACKSAW]

I know it's too late now but you really should adjust that on a short piece of mast before you go up. An antenna anyalizer makes this very easy. I had to turn my rings also just a small amount, that antenna is "broad banded" as Preacher Man said, what freqs do you use most?

[4600 Turbo]

For SWR that good I wouldn't climb. You wouldn't see any difference even if you got it down to 1:1.

Anything you hear or see different would be Imagined.

[209 first class]

im always the guy saying stuff no one wants to hear. i have heard more than once that antrons are adjusted at the factory using an mfj analizyer with no coax, and never to touch or move the rings while installing. people get one home, measure the swr with coax, and think it needs "adjustment". so, they adjust the rings so it reads correctly on the incorrect measuring setup. coax changes your readings depending on its length. 209

['Doc]

209 first class,
Don't believe, or assume things that you don't know. The 'Antron' factory may certainly use an antenna analyzer to 'factory tune' an antenna before it leave the factory, but that does not mean it will be tuned for where you put the thing up. No factory can 'pre-tune' an antenna very close without duplicating exactly how the thing is going to be erected. Doesn't matter what they use to do that tuning with. They can get it 'ball-park' close, but that's it. If you want it any better than that, you will have to do it on site. That goes for all antennas, not just 'Antron'.
You're right, coax length can affect what a meter 'sees', but only when the antenna isn't resonant and has an input impedance matching the rest of the antenna system (50 ohms).
Particular lengths of coax have the ability to duplicate the impedance seen at the antenna input, at the transmitter end of that coax. That particular coax length is an electrical 1/2 wave length or any whole multiple of one, at the frequency it's 'cut' for. If you are close enough to that antenna to do any adjusting to it, you will affect it's input impedance. Which means that when you move away from that antenna, it's input impedance will change. There are 'tricks' to it, but that's basically what's happening. 'Pre-tuned', 'Factory tuned' both mean close, but not really close. That's up to you.
- 'Doc

[North Texas Mudduck]

For that matter just screw it together and throw it up on a pole if the swr are 2.5 or higher dont worry just dropinline one of them magical swrtuners

the swr meter will show 1.0 swr behind the tuner then in front of the tuner its still the same 2.5 to 3 swr

[Century21]

Its about like people around here use to carry thier amps off with there radio to have them ( matched up ) and tuned. While keying the propper amount of power is important. How in the heck can a tech match it up at his house? SWR will change, line voltage probably to. All of that has a effect on your power output.
A antenna tuner , well thats all it is, I dont know if there is a difference between a matcher and a tuner, i thought there was because of the way they actually work. But they all do the same thing. Keep ya from blowing up your radio........
1 more thing, how do you hook up a antenna to a analyzer with no coax? you have to have something to hook it up to the device. Unless you have some of that cordless coax, i have spools of it for sale. I keep tripping over it. guarunteed 100% loss cordless coax. Ill even throw in some connectionless connectors for free.

['Doc]

All an antenna tuner does is match inpedances. Call it a tuner or a matcher, they're all doing the same thing. The only way a tuner can change how an antenna is 'tuned' is by putting it at the feed point of that antenna. Otherwise, all it does is match whatever the impedance of the antenna AND feed line is to 50 ohms, it tunes the whole antenna system. It will certainly change the SWR that the transmitter sees, but from that tuner to the tip of that antenna, nothing has changed, the SWR is still whatever it was to start with. That means that there will be more losses using a tuner than if the antenna was tuned correctly. BUT, it also means that the transmitter will put out full power and not 'cut back' because of a bad impedance match (bad SWR). There is typically less loss using a tuner with an un-tuned antenna than doing that 'matching' in other ways (feed line length). They do work well enough compared to not using one when you need one. The biggest problem with using a tuner with coax is that coax capabilities are the limiting factors, as in ruining the coax.
Can you tell I like having/using a good tuner? Then again, I don't use coax for a feed line very much at all. Whatever...
- 'Doc

[Century21]

Doc, is that why most quality tuners have terminals for ladder line on the back, and some dont even have pl-239's?

['Doc]

Oooo. More than one answer to that. Simplest is that the tuners with both type of connections are for use with both type of feed lines. Only has one type connector on it? Then it's typically only for that type of feed line.
The basic 'parts' of a tuner are all the same (sort of). There are I-don't-know-how-many different 'tuner' circuits there are, but there are a bunch. They do things just a bit differently, but all 'do' the same thing. The way to connect those tuners to the antenna system just depends on what the feed line for that system is. One of the 'biggies' for tuners is if it's made to handle a 'balanced' feed line or not. The 'one size fits all' type tuner that can do both is certainly nice to have, but you can bet that it's gonna do one type feed line better than the other (don't ask, I don't know).
[I do know of one big name, high dollar, tuner that's been around forever that isn't exactly the best thing going. It's very well constructed and well designed, it just assumes you are 'sort of close' to the right impedances to start with. ('Nuther one'a them don't ask thingys. And I'd love to have one anyway!)
Picking a tuner is sort of like picking a shirt. It needs to fit what it's supposed to fit, cover what it's supposed to cover, look halfway decent(?), and last longer than two 'wearings'/washings. And naturally, you gotta have enough $$$ to pay for it, and it be worth whatever you wanna do with it.
- 'Doc

(The only tuner I'd say you shouldn't ever buy is one with my name on it. I don't turn loose of tuners unless they aren't worth having anymore. Bunch of reasons for that, but safest thing is just don't buy it. sort of)

[PONY EXPRESS]

All an antenna tuner does is match inpedances. Call it a tuner or a matcher, they're all doing the same thing. The only way a tuner can change how an antenna is 'tuned' is by putting it at the feed point of that antenna. Otherwise, all it does is match whatever the impedance of the antenna AND feed line is to 50 ohms, it tunes the whole antenna system. It will certainly change the SWR that the transmitter sees, but from that tuner to the tip of that antenna, nothing has changed, the SWR is still whatever it was to start with. That means that there will be more losses using a tuner than if the antenna was tuned correctly. BUT, it also means that the transmitter will put out full power and not 'cut back' because of a bad impedance match (bad SWR). There is typically less loss using a tuner with an un-tuned antenna than doing that 'matching' in other ways (feed line length). They do work well enough compared to not using one when you need one. The biggest problem with using a tuner with coax is that coax capabilities are the limiting factors, as in ruining the coax.
Can you tell I like having/using a good tuner? Then again, I don't use coax for a feed line very much at all. Whatever...
- 'Doc

Very Very good info there Doc Keep up teh nice work.....

Actually 1 important thing has been missed .The Antenna Tuner not only allows the radio to see 50 OHM load which not only helps the transmitter get fooled into putting out full output but it also helps the RECEIVER see a 50 ohm load as well for improved receiving from a mis-tuned antenna .

['Doc]

PONY EXPRESS,
You're right! But since receivers are just not as 'picky' about what they eat, it isn't as important to them as it is to the transmitter. The reason being that a typical receiver is an order of magnitude more sensitive/selective than it has to be to start with. Not that it's never completely unnecessary, but in most cases it's just not worth too much worry.
- 'Doc


(and I didn't say anything about that because I just didn't think to do so.)