Автор Тема: Balun  (Прочитано 4121 раз)

US7IGN

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Re: Balun
« Ответ #15 : Октября 26, 2020, 08:33:00 pm »
Кстати о балунах.
Свои для полевых антенн делаю из таких колец https://www.sotabeams.co.uk/balun-toroid/

Typical Application
1:1 Baluns should be wound as shown in the diagram below.

Each pass through the hole in the toroid is a turn.

For 50MHz 3 + 2 turns of RG58 is recommended.

For HF 7 + 6 turns of RG174 is recommended.

Hold the ends in place with cable ties.

This diagram shows 4 + 3 turns, 4 on the left and 3 on the right.

The crossover through the centre is not counted in the left or right sets of turns. The crossover is symmetrical, so there is no particular reason to include it in one set rather than the other. But since the crossover does pass through the hole in the toroid, the total number of turns is technically 8 (4+3, and +1 for the crossover).

The exact number of turns is not critical, there just have to be enough to give sufficient common mode impedance at the lowest operating frequency.

US7IGN

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Re: Balun
« Ответ #16 : Февраля 22, 2021, 03:29:00 pm »
Как измерять антенным анализатором кольца https://www.eham.net/article/7596

Nowadays, the MFJ 259B Antenna Analyzer has become almost ubiquitous in the modern ham shack. And believe it or not, you can use one to check those surplus units to make sure they'll do the job. You'll need enough hookup wire, size 22 is ideal, to make 5 passes through the bead plus enough to connect the ends to the analyzer. Set the frequency to 2 Mhz, and measure the reactance. If it is mix 43, the inductive value will be approximately 500 ohms. Pushing the mode button three times will bring up the reactance menu which should show 40 uh or so. Any less than this and you may not have mix 43, and it may not work properly. If the reading is higher, that's fine to a point, but double these figures may indicate mix 77 (ui=1800), which is better suited for 160-meter suppression. By the way, the 259B hasn't enough range to check mix 43 at much more than 2.5 Mhz unless you reduce the number of turns

US7IGN

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Re: Balun
« Ответ #17 : Марта 11, 2021, 06:12:54 pm »
провел сегодня лабораторные работы и проверил свои балуны на 43 амидоновском кольце и отклоняйке от телевизора. домотал по пару витков.

US7IGN

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Re: Balun
« Ответ #18 : Июня 27, 2021, 08:36:54 am »
RF Inductance Calculator for Single‑Layer Helical Round‑Wire Coils

https://www.hamwaves.com/qoil/en/index.html