Subj : 50ê - 200ê HF Transformer
To   : WW
From : G8MNY
Date : Sat Sep 07 2019 11:01 pm

G8MNY    TECH     07.09.19 06:15l 53 Lines 1642 Bytes #365 (0) @ WW
BID : 20571_GB7CIP
Subj: 50ê - 200ê HF Transformer
Path: OK0NBR F3KT OK0NAG DB0ERF DB0RES DB0EEO DB0GOS ON0AR GB7CIP
Sent: 190907/0908Z @:GB7CIP.#32.GBR.EURO #:20571 [Caterham Surrey GBR]
From: G8MNY@GB7CIP.#32.GBR.EURO
To  : TECH@WW

Here is 4:1 Transformer for HF long wires     (New Nov 09)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
THIS IS NOT A BULAN!
An auto-transformer may well make matching a long wire possable on AUTO ATUs
that do not have a good impedance range. (e.g. only for SWRs of   3:1) 

It is possable to rewire/switch a bulan to do this.
 
At this ratio the ferrite only has to handle 50% of the RF power!
Turns Ratio 5:10 giving a Z ratio of 1:4

e.g. 5 turns for 50ê, 10 turns for 200ê Balanced.

             ÚÄÄÄÄÄÄ¿
             ³      ³6      10
             ³      ³Ú¿Ú¿Ú¿Ú¿ÚÄÄÄÄo
             ³      ÃÙÀÙÀÙÀÙÀÙ   200ê
  50ê Txr  ³ ß ³    ³±±±±±±±±   
Unbalanced ÀÄÂÄÙ    ³±±±±±±±±   
             ³      ³Ú¿Ú¿Ú¿Ú¿   
             ³      ÀÙÀÙÀÙÀÙÀÂÄÄÄÄo
             ³       5     0 ³   _³_ 
             ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ   ///

Make sure they are phase & connected correctly.


In general a transformer turns ratio is square root of the Z/Z.
So for 600ê to 50ê that is û600/50 = û12 = 3.46 or 2:7 3:11 4:14 5:17 turns 
etc.

An autotransformer tapped system where the lower turn is a tapping of the total
also the lower turns should be 2x thicker!
             ÚÄÄÄÄÄÄ¿
             ³      ³6           17
             ³      ³Ú¿Ú¿Ú¿Ú¿Ú¿Ú¿ÚÄÄÄÄo
             ³      ÃÙÀÙÀÙÀÙÀÙÀÙÀÙ   600ê
  50ê Txr  ³ ß ³    ³±±±±±±±±±±±±±
Unbalanced ÀÄÂÄÙ    ³±±±±±±±±±±±±±
             ³      ³Ú¿Ú¿Ú¿Ú¿
             ³      ÀÙÀÙÀÙÀÙÀÂÄÄÄÄÄÄÄÄo
             ³       5     0 ³       _³_
             ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ       ///



Why Don't U send an interesting bul?

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