Imax 2000 swr problems

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Astro fantom
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Imax 2000 swr problems

Post by Astro fantom » 01 Oct 2019, 22:25

For some odd reason the swr on my imax seems to have a mind of its own..
I can use it one day and all is fine swr at 1.1/1.4 :twisted: from 26 to the low end of 28mhz no problems then go on again the next day and its 3 plus across the bands..
No ideas why it does this as it can be caml weather and dry and still be high but then sorts its self out the next minute..
I have took it down cleaned the s0239 made sure the drain hole was clear and put it back up but no change so now wondering if this antenna is ready for the bin or does anyone have any ideas why i seem to be struggling with high swr as its become damned annoying now

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Re: Imax 2000 swr problems

Post by 108EH002 » 02 Oct 2019, 11:58

I wouldn't say its ready for the bin,cleaning a pl259 isn't the same as cutting the coax and re-doing the pl259's again.

1) I would start with doing all of the pl259's first.
2) If still the same I would then change the coax.
3) Still the same then I would consider changing the antenna.

Is there any chance a bird has maybe hit your coax ?
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Re: Imax 2000 swr problems

Post by The Collector » 02 Oct 2019, 18:42

Did you clean the threads on the joints when it was down with a wire brush before tightening them again and waterproofing them with self-amalgamating tape etc?

If say the top section isn't making a good permanent contact, it might be swaying and connecting/not connecting/connecting.. ditto..

Just a thought if it's not co-ax related.

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Re: Imax 2000 swr problems

Post by 108EH002 » 02 Oct 2019, 19:38

Had similar results with my 6 year old Imax a few month ago,I re-done the plugs and still the same,but after renewing the coax it worked ok again like before,hopefully it's a plug or coax problem.

Maybe the pl259 at the Imax,as one of the locals had the same with a 1 year old Imax,it was doing the same with the swr readings it was showing,and it was the old coax (4 year old) from his silver rod that he was using,after he done the plugs again it was fine,the last plug to be re-done before the swr dropped,was the one at the Imax ;)
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Re: Imax 2000 swr problems

Post by Astro fantom » 11 Oct 2019, 20:41

Thanks for all the replies and suggestions yes i have taped all the sections at each join with self amalgamating tape i do this as a matter of course when doing antenna installs as i have had past experience with water ingress resulting in high swr readings and with regards coax i am currently using rg8 mini although not sure if this is good or bad coax to use and it came with one plug already fitted and i soldered the other end when it was cut to size..
To be honest it was fine when it was first set up just seems to have gone bad over a period of time..
I was thinking of buying rg213 coax and seeing if that was any different with regards swr readings as i dont know if there’s any damage in the cable run at any point as it tucks under the roof tiles to feed into the loft and could possibly be nipped under there..
Im currently thinking new coax and see if the problem exists and if so new antenna although what to get as a replacement is tricky as i have heard all the arguments for and against fibreglass antennas and alloy versus fibreglass so if i do decide on a new antenna it will be a difficult decision..
Id like to get it done before the weather gets too bad as i live in a top floor flat three up and have to climb out the bathroom window to get on the neighbours roof to access the thing so helps when its not chucking down with rain🤣

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Re: Imax 2000 swr problems

Post by prettypolly » 12 Oct 2019, 00:24

I use bike inner tubes to seal a joints with mastic

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Re: Imax 2000 swr problems

Post by The Collector » 12 Oct 2019, 13:13

It won't hurt to get some nice, shiny new 213 - the best you can afford. It should hopefully last you 20 years then.

Buy 2 metres more than you need so you have plenty of extra co-ax to redo the PL plugs in the future in case of any water ingression at the end, or say accidental damage at the radio end. Don't coil up.any excess co-ax though.

Wrap over the PL plug when attached to the aerial too with amalgamating tape or similar. It'll not only seal it, but should stop the plug from vibrating or working itself loose. Ensure you wind the tape on the right way too, from 4 inches from the end of the co-ax UPWARDS to and around the PL plug, getting it as snug as you can to the aerial base ;)

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Re: Imax 2000 swr problems

Post by Astro fantom » 12 Nov 2019, 17:35

Yeah sounds like a plan to me to be fair and it rules out any coaxial problems that might exist already as there is a pinch point where the cable feeds under the eves so runs between the roof tiles and the brickwork altho that said i pulled it through a while back and all seemed ok at a glance.
I did however look at the antenna and where its bonded at the base underneath the tuning rings there seems to be a gap between where the glue is and the actual metal sleeve it’s supposed to be glued into so looks like the antenna is trying to lift out of the metal sleeve its bonded into and now its getting to winter its looking like i will be probs replacing the antenna as well as the coax in either a blizzard or some other wonderfull stom that alaska throws our way..
Looking on the positive side of things though if i can manage to source a 20ft alloy scaffold tube it gives me the ideal excuse to replace the 12ft one currently in place and pop the new antenna high in the sky bearing in mind its three floors up already and is quite visible above all the rooftops
So should perform even better with some extra height added...i did tell the missus id leave it as it stands but i doubt she will notice too much for the sakes of another 8ft.😆

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Re: Imax 2000 swr problems

Post by The Collector » 12 Nov 2019, 22:47

Just tell her it's always been that high and see if you can get away with it.

My missus didn't notice the Antron I had up for about 5 years in the conifers as well as the recently-hoisted Imax with tank-whip sticking up 10ft out of the top of them now! :)

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Re: Imax 2000 swr problems

Post by Master Virus » 16 Nov 2019, 16:53

The Collector wrote:
12 Nov 2019, 22:47
Just tell her it's always been that high and see if you can get away with it.

My missus didn't notice the Antron I had up for about 5 years in the conifers as well as the recently-hoisted Imax with tank-whip sticking up 10ft out of the top of them now! :)
That's what makes me laugh, the things we do to hide things from the wife.
I'm thinking the collector is x-army or sas stealth antennas sorted :lol:
Must be tall bloody conifers :lol: :clap:

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Re: Imax 2000 swr problems

Post by The Collector » 16 Nov 2019, 22:16

Can't tell you anything mate...lol.

The conifers are about 30ft...well the ones I haven't trimmed down yet are. When the others are trimmed and the Imax becomes bloody obvious, I might be in BIIIG trouble with 'er-indoors ;)

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Re: Imax 2000 swr problems

Post by Astro fantom » 20 Nov 2019, 12:17

Yeah to be fair my missus is quite good that way and was happy to let me hoist the imax up on the back of the flat despite the length of it with the pole but as soon as i said i wanted a 20ft pole to get it a little higher she was dead against the idea but seems to be warming to it now as i said i would add an extra wall bracket to support the thing and there would be zero chance of it coming down anytime soon so whilst im winning im looking for an alloy 20ft pole and will just renew the entire set up to rule out any further problems with swr....my next mission is to convince the neighbours its safe as it does tower above them a little as it stands at the moment but that said the flex in the alloy pole has helped it survive the storms of the past three years so i dont forsee any future problems with an extra 8ft🤣😎👍

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Re: Imax 2000 swr problems

Post by The Collector » 20 Nov 2019, 18:10

Make sure you put anti-vibration washers on the U-bolts so they don't come loose. An old neighbour didn't do that and the steel scaffold pole slid, dropped through a tiled garage roof and damaged the wing of his neighbour's car.

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Re: Imax 2000 swr problems

Post by Master Virus » 25 Nov 2019, 00:34

The Collector wrote:
16 Nov 2019, 22:16
Can't tell you anything mate...lol.

The conifers are about 30ft...well the ones I haven't trimmed down yet are. When the others are trimmed and the Imax becomes bloody obvious, I might be in BIIIG trouble with 'er-indoors ;)
I pray she never gets fed up and wants a fence :D

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Re: Imax 2000 swr problems

Post by The Collector » 27 Nov 2019, 10:09

There is a fence there already, but it's just inside the conifers. However, as they're growing taller and taller (3ft a year), the roots are pushing up on the bottom of the fence panels and one is buckling, so that's the only reason they're getting topped off by 10ft.

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