SWR Meter

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SWR Meter

Postby JonnyAlpha » Fri May 27, 2016 10:40 am

Hi;

I am building a couple of DIY Antenna for 70cm band High Altitude, before I connect to my radio equipment I have been advised to use an SWR meter to check the antenna.
Looking on eBay and Amazon (and Maplins) there are lots to choose from so I need some help? Don't want to spend a fortune, just need something that works.

Thanks
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Re: SWR Meter

Postby m0lsx » Fri May 27, 2016 11:14 am

Avoid Maplins, first it will be a rubbish Moonraker item, secondly it will be way over priced & thirdly Maplins know bugger all about anything radio & give truly awful advise & support as a result.
Your issue is going to be you are limited to milliwatts & that means a very sensitive & thus expensive SWR meter is needed, a normal £30+ SWR meter will not measure half a watt properly. Plus SWR is only one aspect of what makes an effective antenna.
You would be better off with either an antenna analyser, which are expensive or a Grid Dip Meter (also known as a dipper.)
The dipper is not as good as a analyser, but it costs a fraction of the price & is better for than a SWR meter.
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via http://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
73 De Alan (M0LSX.)
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Re: SWR Meter

Postby G4RMT » Sat May 28, 2016 6:27 pm

You could be better off finding an old bigger satellite dish - and making a very simple dipole to put at the feed point. If you can find a 1.2 m dish, it will have plenty of gain, and a simple dipole, cut accurately will have a naturally good VSWR. You can have quite a lot of fun with a dish and cobbled together pan and tilt head for following aerial objects. My own experience building UHF antennas suggests that a dish is much more predictable without access to decent test gear as Alan says.
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Re: SWR Meter

Postby m0lsx » Sat May 28, 2016 7:19 pm

A double quad (bowtie) for 70 cm can be very effective too.
There is a good & easy build on this site about half way down the page.
http://g6ohm.webs.com/antennadesigns.htm

And this site is good too.
http://www.hamuniverse.com/doubletwinquad.html
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