SWR a 5/8 silver rod

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pete_uk
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SWR a 5/8 silver rod

Post by pete_uk »

I read that the 5/8 wave rods are harder to SWR than the halfwave. its that true? What about the ones with the little radials sticking out? i ask becuse one of the places selling them says so...

but i might get my card out and help the economy by getting one, some rg-213 and some pl239's :P

well its almost christmas!
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Yeti
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RE: SWR a 5/8 silver rod

Post by Yeti »

not really - and the radials are pretty much just a gimmick - I used to sell them years ago.
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RE: SWR a 5/8 silver rod

Post by pete_uk »

Yeah I guessed that!
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RE: SWR a 5/8 silver rod

Post by pete_uk »

What is the length (to the nearest mil) of a 5/8 antenna at 27.4000mhz? I'm looking for a flat SWR from EU1 to UK 40 as near as poss.

cheers peeps
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Post by fez »

Just buy one!

They should come pre-marked but slight tuning may be needed, Your thinking way too far ahead.
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Post by Yeti »

Yeah, you're panicking about nothing. The aerial will come with permanent marker marking where each section should be tightened, and they have plenty enough bandwidth to get a good SWR across all 80 legal channels. below 1.5 to 1 at each end and you're laughing - if you're aiming for 1 to 1, you're never going to get it (or notice the difference!)
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Post by rocket »

The tuning markings will coincide with the CEPT midband.

To get a better SWR on our higher UK40 frequencies you will need to make the antenna shorter, and if I had to guess then I would say to shorten it by 6 inches and then do some VSWR measurements for fine tuning.
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Post by pete_uk »

OK, she's up but at the moment she is fed with the rg-58U coax as I dont have time to do the RG-213.

I am having trouble getting the swr down though. on EU 1 i get about 1:2:1 on low power (about 3-4 watts) but put the power up it goes up to 1:5:1 easily.Its the same all the way through the channels and bands. I only have expirence of half waves so I dont know what to expect from one of these. I dont know if I should go higher or lower!?
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Post by Yeti »

You're complaining about a 1.5 to 1 SWR? You're not going to get it any better, and if you did, you wouldn't even notice the difference.
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Post by pete_uk »

humm. I am just a bit unsure becuse my dipole and halfwave would cause the little needle to hardly move so i guess i was a bit spoiled!
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Re: SWR a 5/8 silver rod

Post by PoisoN »

you need an anyliser to do it properly really. Pick a centre frequency where you want the swr to be its lowest like 27.50000 and you are going to have a curve either side where the swr will go up. You want to try and set the centre frequency so that you are 1.5 on channel 40 UK and 1.5 on channel 1 mid band/ Eu. If you can achieve that you done a good job. These antenna's are not very wide banded so finding that happy medium is harder. They are good if you just want to cover UK40 or a bit of mid band. But beyond that you are going to see higher swr. And probably have to use an atu to compensate. If you want to cover wider frequencies buy a wide band antenna. Like the Imax or Gainmaster etc.
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Re: SWR a 5/8 silver rod

Post by original45 »

I have seen silver rods flat, I have seen them not able to get a good swr on uk 27..81 top end.
I would have recommended the sirio how 5/8 over the otgers.
Some are terrible and the slits in ends of tubing won't close tight enough to securely clamp the outer to inner tube.
You can test this by trying to twist section couplings.

It's suggested some antennas work better without a flat 1-1 swr too I read.

Also when I swr a antenna I always set to lowest power 1 watt first,then if ok up power .now are you 're calibrating for increased power, if not that effects swr shown.

My friend has a silver rod 1-1 a 80/90s version thicker tubing 21'+. I too have a couple a older one again 1-1 modern version it's notably higher and crap on high UK band.

Ensure the antenna is grounded well.upload images how it's mounted.
Is it on kt brackets on a wall,chimney on scaff in garden into soil.If latter soak around pole with water.

Try the slits if too loose too
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Re: SWR a 5/8 silver rod

Post by The Collector »

After 14 years, I hope he's sorted it ;)
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Re: SWR a 5/8 silver rod

Post by original45 »

Omg lol dave.
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Re: SWR a 5/8 silver rod

Post by NightProwler »

The Collector wrote: 08 May 2022, 19:25 After 14 years, I hope he's sorted it ;)
:lol:
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