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G8MNY > TECH 14.11.20 21:19l 56 Lines 1645 Bytes #999 (0) @ WW
BID : 12557_GB7CIP
Read: GUEST
Subj: 50ê - 200ê HF Transformer
Path: IZ3LSV<IK8VKW<F1OYP<AB0AF<KE0GB<N7HPX<GB7CIP
Sent: 201114/0958Z @:GB7CIP.#32.GBR.EURO #:12557 [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?
73 De John, G8MNY @ GB7CIP
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