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Base New Imax wont tune 11m....this sucks

OCD...good one.
If you dont like my topic, please move on. I dont need help by trolling.

They're not trolling, you're being OCD about it. I do contesting on amateur radio, I want the best performance I can but as long as the SWR is below 1.6:1 then I don't care after that. There is absolutely no advantage at all in trying to get a 1:1. A perfect SWR is what fools chase.
 
Well I'm the fool that gets a flat match in the end.
I had a maco 5/8 and I spent a couple days (maybe more I forget) messing with it trying to get it under 1.6.
Finally I found if I pull the vertical element out of the base insulator a 1/2, the match dropped like a rock.
Never had a problem again.

I passed it on to my friend on youtube, it worked for him after he was fighting with his.

Thats the problem with people today. "good enough" and a give-up attitude gets you nowhere.
This isn't my first rodeo and the Imax used to be a wicked performer, flat match from 26-28 with ease.

These pieces of crap are an embarrassment of an antenna and a counterfeit IMO.


Read the comments:


I did that and it worked! Thanks for the advice. Here is the follow up video...I am down to a 1.04 now!
 
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Thats the problem with people today. "good enough" and a give-up attitude gets you nowhere.
While I applaud your efforts I think too many people are obsessed with "low SWR". I constantly run with an SWR of 1.6 or even 2.0.. its never a problem. Of course, the caveat is I am not running high power so maybe if I was I would think differently.
 
Thats the problem with people today. "good enough" and a give-up attitude gets you nowhere.

When it comes to SWR, perfection is irrelevant. Performance wise getting a 1 : 1 match compared to a 1.5 or even 2 : 1 matches will make no difference in how well your setup performs. Their is simply not enough of a difference between them to notice a difference.

And when you have equipment that gets hot just because you have a 1.4 : 1 match, then the equipment is faulty. If the equipment gets hot at this SWR because they are trying to squeeze every watt out of it, like a lot of CB amps, then the equipment was designed to be faulty, and again, for a few extra watts that you will never notice the difference on in the real world anyway.

Some antennas have multiple adjustments you can make, such as the Maco vertical antennas that were mentioned. And for the record, peak gain on said Maco antennas, as per a field strength meter, isn't where you get a perfect SWR match.

On the imax, if you are really that concerned with a pointless perfect SWR match, you can also vary the distance away from the antenna the choke you mentioned above is. This may take some experimentation on your part, which you seem to be willing to do.


The DB
 
I believe I would go back to the Maco if I had that many problems with the IMAX.
73’s
David
I might. The problem is the rain.

I find my equipment runs cooler with a lower match and same with the coax being a proper multiple.
The imax was designed to be a flat swr over a wide range.
Now it is like squawker said, match goes up .05 every channel.


I'm gonna try to find a nos or lightly used vintage imax from when they did it right.
Then just to be sure I'm gonna buy some RG213 because it worked for me in the past.
I've been told that some operators noticed LMR400 wouldn't give them the SWR they expected and found the LMR400 didn't live up to expectations. RG213 just co-operated much better.
 
357,
It seems this venture has been full of pot holes for you.
I have been entertaining installing a 5/8 vertical at my location. I currently only have a 3 element beam for 10/11 mtrs. My installation options are very limited to 2 trees in my yard. One being about 90 feet tall and closest to my operating postion requiring about 125’ of coax and the other about 60’ tall requiring about 250’ of coax. 90 ft location requires coax crossing the driveway ( doesn’t make the wife happy). Going under the driveway is not an option as the utilities are underground parallel to the drive on the side of the tree. Add to this that I am too old to climb a tree and a 5/8 vertical with radials severely complicate a tree installation. So I am shopping for a decent vertical without radials that is broadbanded, can survive strong winds and will stand up to weather/corrosion for some time and is not a lightning magnet. I guess I am looking for the “Gold Plated Unicorn”!
Hence I have been following this post to see how you overcome the less than stellar performance of this IMAX.
Good luck.
73’s
David
 
It hasn’t taken a lot of reading for me to understand I will never “bag” the “Gold Plated Unicorn”. Just something to mull over for the last couple years. Until my 25 year old R/S rotor gives out it won’t be a priority. The 3 element Yagi is working fine. It seems that rotor is tougher than I have given it credit for.
73’s
David
 
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Gary, I've tried modeling this antenna, but there are too many dimensions missing in the link above to be sure.

What is the space between the brackets?

Can you describe the details for the tuning stub? They show a length. But how does it works to tune the ranges noted?

It doesn't even show the length and diameter dimensions for the mounting bracket noted as the base assembly AA. It does show BB throught EE at 48" inches each which = 192" and then the overall length chart shows the overall length is 192" at the mid band. I don't get it...the base assembly does not appear to be included in the overall length except in Fig 3.

There are other dimensions that are important as well if a model is to try and even get close.

Maybe you help me with this?


This may be of some help although there are no values to see it is an inside look. Ok thought we were still talking about he Imax 2000

imax schems.JPG
 
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