ex UC2LEG (1990-1994), EU3EU (1994-2014: 20 years of very little activity)
I am not a member of QSL bureau, but I log my contacts in eQSL and LoTW.
If you need my printed QSL, just send me your card direct with SAE. Postage is welcome but not absolutely necessary, I will send my card direct to you in any case.
My achievements after two years of activity (since March, 2014), mostly on weekends.
My current antenna: 14-30 MHz 11-element "circularizing tau" LPDA made by RA3DRC (antenna-su.ru), designed and optimized for best performance on amateur bands by RA3LE. The "circularizing tau" optimization (as W4RNL named it in the ARRL Antenna Handbook) allows excellent F/B ratios >20dB even on 20m and 10m, unlike conventionally designed LPDAs that suffer from poor F/B at their working band edges.
Homebrewing is a very significant part of my radio hobby:
For 2016 summerhouse season, and for portable activity, I've built a simple extremely lightweight 2 el Yagi beam for 20-17-15 m bands. I don't need 12 and 10m bands at this part of the solar cycle because of poor DX propagation. The Yagi is on the very short 2 m boom. The antenna weighs 5 kg only, so almost everything can be used as a mast for it. For example, I used 9m of 30x30 mm aluminium box profile.
Feedpoint utilizes beta (hairpin) match, I simply used 0.5 uH aircore coil across the feedpoint. It is tuned once for 20m band only, and is reused unchanged on 17 and 15m. This greatly simplifies changing the band which is performed in couple of minutes by laying down the mast with the antenna using the pulley on a wall, and then by moving telescoping element tips to predefined positions.
Despite the short boom length, the antenna provides >4 dBd gain and reasonable 12-14 dB F/B ratio on all of its bands. It can be quickly assembled and disassembled, unlike the popular Hexbeam and Spiderbeam designs (they provide lower gain by the way, though better F/B).
12m aluminium alloy tower with lift (by Antennae Depot - UA2FZ) with temporary antenna: 4 el monoband Yagi for 18 MHz band on 6m boom. The first director acts more like lossless matching element providing SWR 1.0 at 18.120 and even adds some gain. Antenna needed no tuning at all, I've just carefully set the modelled dimensions and obtained the expected parameters.
By sliding the telescoping element tips inside the thicker tubings to marked positions, this antenna can be easily transformed to a perfect 21-24-28 MHz monoband OWA Yagi with even better parameters. Element positions on the boom are not changed.
The docs (MMANA-GAL files, drawings and photos, measurement results in Touchstone s1p format) are in ZIP file here.
Here is the very lightweight mod of the above mentioned 4 el Yagi, but on a shorter boom which makes it more portable.
It is actually a 4 element OWA Yagi for 10 meters band on 4 meters long boom. The design uses only 2 meters long aluminium alloy tubing (mostly square) available from the local DIY store at a very reasonable price. The antenna works as calculated from scratch, providing SWR < 1.1 in the 28.0-28.75 MHz range, with the same gain (modelling shows 8.3 dBi in the free space) and F/B ratio (> 20 dB modelled, but actually more in reality on distant paths) across all of this part of the band. This is what I expected from OWA design, and what I've obtained without difficulties. It took just one weekend to build and install this antenna.
But this is not all. Modelling showed that adding telescoping extenders to the elements of this OWA Yagi allows perfect wideband matching to 50 Ohms and excellent F/B > 20dB on 17m, 15m and 12m bands! And this matching is lossless, moreover, it adds 0.5 dB to antenna gain, so it works like an excellent 3.5 element Yagi for this particular boom length. Tried this idea on vacations in June 2015, with great success. Used it as multibander, the only drawback is that I had to put it down every time I wished to change the band. It takes 15 minutes. :)
See it hovering over my summerhouse where I normally spend my vacations, with extenders set for 17m band:
My homebrew four-band (20-17-15-12 m) very lightweight 2-element "Jungle Job" type beam (G4ZU) at 12 m above the ground. Multiband matching is achieved by using a carefully calculated T-match at the feedpoint with a variable capacitor rotated by a small remotely controlled servo motor. The whole mast is rotated by Yaesu G-1000DXA rotor from bottom.
For seven months in service, only on weekends with barefoot 100 Watts, 251 DXCC countries were worked using this simple antenna. DXCC was confirmed on each of its four working bands. Now this antenna is disassembled.
7458344 Last modified: 2016-07-22 15:37:53, 8379 bytes
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Book Totals: 10933 qso's 2020 confirmed