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  • 1:1 HF Balun

    From G8MNY@21:5/101 to WW on Sat Sep 7 23:02:03 2019
    G8MNY TECH 07.09.19 06:15l 35 Lines 1164 Bytes #365 (0) @ WW
    BID : 20569_GB7CIP
    Subj: 1:1 HF Balun
    Path: OK0NBR F3KT OK0NAG DB0ERF DB0RES DB0OVN DB0GOS ON0AR GB7CIP
    Sent: 190907/0902Z @:GB7CIP.#32.GBR.EURO #:20569 [Caterham Surrey GBR]
    From: G8MNY@GB7CIP.#32.GBR.EURO
    To : TECH@WW

    Here is 1:1 balun for HF freq`s (New May 09)
    (8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
    At this turns ratio the ferrite has to handle 50% of the RF power! It is useful where the unbalanced feeder's outer may be at a high Z & a choke balun will not work. (e.g. up in the air)

    Turns Ratio 10:10 giving a Z ratio of 1:1
    e.g. 10 turns for 50Ω, 10 turns for 50Ω Balanced.

    ┌───────┐ ┌──────────────────────────o
    │ │10 │5 0
    │ │┌┐┌┐┌┐┌┤┌┐┌┐┌┐┌┐┌───┐
    │ └┘└┘└┘└┘└┘└┘└┘└┘└┘ │ 50Ω
    50Ω Txr │ ▀ │ ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ │
    Unbalanced └─┬─┘ ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ │ Balanced
    │ ┌┐┌┐┌┐┌┐┌┐ │
    │ │└┘└┘└┘└┘└───)───────────o
    │ │5 0 │
    └───────────────┴────────────┘

    5 trifilair turns on Amidon T 200-2 TOROID CORE

    Make sure the windings are phase & connected correctly.


    See my tech bul "Coiled Choke Balun for HF"


    Why Don't U send an interesting bul?

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