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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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22nd Apr 2019, 9:07 am | #1 |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,761
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EU1KY Antenna Analyser Kit
When I was active in amateur radio, all of my antennas - whether for VHF or HF - were home constructed, including a replica of a G4MH mini-beam on which I gained the Worked all Continents Award (Indonesia, Brazil, Japan, Africa, Canada, Australia etc), plus trapped dipoles & baluns, trapped verticals, a 'Cobwebb' and so on. I found an antenna analyser invaluable - back then an MFJ '259'.
I haven't been active on air for more than 15 years and no longer have any amateur radio equipment or antennas. Hence, I'm out of touch so I've no idea whether anyone bothers much these days with homebrewing antennas. I suspect not, but that said, some may do and even with shop-bought antennas, maybe there's some interest in seeing how they perform and tweaking them and the feeders for best SWR on the desired bands. With that in mind, while browsing (in connection with homebrew amplified receiving loops), I came across this kit which I thought might be of interest to some forum members. Building and setting it up seems to be comprehensively covered, albeit a little 'ticklish'. It may be that in my ignorance, it's already widely known about in amateur radio circles, but I can't recall seeing it mentioned before on the forum. These links might therefore be of interest: https://bitbucket.org/kuchura/eu1ky_aa_v3/wiki/Home https://www.elekitsorparts.com/produ...nalyzer-eu1ky/
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David. BVWS Member. G-QRP Club member 1339. |
22nd Apr 2019, 9:45 am | #2 |
Dekatron
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,932
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Re: EU1KY Antenna Analyser Kit
Yes ,plenty of interest in home brew aerials,in fact I have just joined a facebook group on same subject.
I got a MFJ259 a few years ago s/hand and very good too.
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G8JET BVWS Archivist and Member V.M.A.R.S |
22nd Apr 2019, 11:03 am | #3 |
Dekatron
Join Date: Jun 2016
Location: London, UK.
Posts: 3,687
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Re: EU1KY Antenna Analyser Kit
Interesting kit. Some thoughts further down...
I am mostly cheap and lazy so I would fear that would exceed my budget to start with. I started by just cutting the antenna slightly long and then use my radio's built in SWR meter and trim it to a low SWR reading. Seems to do the job well enough, or so I thought. Had a high SWR reading I couldn't get down one day so decided to do something about it. It's when your antenna goes wrong the analyser is helpful. Thus the "crapalyzer" was born out of junk box parts. This is a Sweeperino [1] which is an Si5351A oscillator and AD8307 power meter. It was supposed to be an Si570 but I couldn't find any so I rewrote a chunk of the firmware to support that. The thing has a return loss bridge attached to it that you plug into the antenna and tune it for the greatest loss (most power up the feed). Works nicely but has some spurious responses as the Si5351A is square wave output. The analyser after much head scratching pointed out my current balun feed was poorly soldered. I could have found this out with a DMM but it didn't occur to me until later Then I bought a second hand MFJ 259C which I found out was battered and the batteries had leaked in it at some point. I had to do some repairs on it to get it usable including replacing the front end diodes. At this point I'm less inclined to bother with anything that requires futzing in this space which means no kits and no second hand stuff. Rig Expert AA-35 Zoom it was and only cost me £40 more new than the second hand MFJ-259C! https://rigexpert.com/products/anten...rs/aa-35-zoom/ ... should have got something like this to start with. Would have saved hours of my life. Price isn't that far off the full kit / assembled price for the aforementioned analyser. [1] http://hfsignals.blogspot.com/p/sweeperino.html |