HF Yagi benchmarks – what commercial designs achieve
What commercial and published HF Yagis achieve for a given boom length, what theory says about the limits, and how far the published figures can be trusted.
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Czech amateur radio station
OK1M
Contesting, DXpeditions and home‑built RF hardware. Welcome to the station page of Michal Rybka, OK1M.
Latest posts
CONDXLIVE – live HF propagation for contesters
CONDXLIVE is a live HF propagation overview for contesters: a single full screen in dark mode that, for your locator, shows which band and which direction is worth working right now and over the next 48 hours. It covers the 160,…
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CQ WW DX SSB 2026 – SO(A) AB LP – IH9/OK1M
Last weekend of October means one thing: CQ World Wide DX SSB. This year I took part from Pantelleria Island (IOTA AF-018) as IH9/OK1M, CQ Zone 33, African Italy, a separate country multiplier in CQ WW. Category: Single Operator…
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OK1M 7-element multiband Yagi for 20/15/10 m
A 7-element multiband antenna for contesting on the 20, 15 and 10 m bands: 2 elements on 20 m, 2 on 15 m and 3 on 10 m, all on a 4.36 m boom with a single 50 Ω feed line. It is a shorter sister of the 9-element version.
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OK1M-PyminiNEC3 – antenna modelling in Python
OK1M-PyminiNEC3 is an antenna modelling platform with the MININEC 3 calculation core and MMANA-GAL pro conventions. It reads antenna models in the MMANA-GAL format (.maa), computes them with the method of moments and produces the…
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144 MHz LNA with PGA-103+ in an aluminium case
A low noise amplifier for the 144 MHz band built around the PGA-103+, with a low pass filter at the input, a band pass filter at the output and two bypass relays, all in an aluminium case. The measured gain is 19 dB.
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