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* Input Transformer (T1 on Charlie's - T2 on this board)
 
* Input Transformer (T1 on Charlie's - T2 on this board)
 
* Need to calculate turns ratio
 
* Need to calculate turns ratio
* 50:80.8 Ω
+
* 50:80.8 Ohms
 
* n = sqrt(Zout/Zin)sqrt(80.8/50) = 1.27 turns ratio
 
* n = sqrt(Zout/Zin)sqrt(80.8/50) = 1.27 turns ratio
 
* Turns choices
 
* Turns choices
 
* Minimum number of turns
 
* Minimum number of turns
 
* Rule of thumb - want Xl (coil impedance smallest value) to be least 4-5X the load
 
* Rule of thumb - want Xl (coil impedance smallest value) to be least 4-5X the load
** Load = 80.8 Ω
+
** Load = 80.8 ohms
** 5 * 80.8 Ω = 404.2 Ω minimum
+
** 5 * 80.8 ohms = 404.2 ohms minimum
 
*** More turns = larger capacitance and drops bandwidth
 
*** More turns = larger capacitance and drops bandwidth
 
** Toroid is FT37-43
 
** Toroid is FT37-43
 
** From [http://toroids.info/FT37-43.php Toroid page]
 
** From [http://toroids.info/FT37-43.php Toroid page]
***  Xl = 404.at 9 MHz is 4.5 turns, round up to 5
+
***  Xl = 404.4 at 9 MHz is 4.5 turns, round up to 5
 
** Try nearest integer numbers turns ratios
 
** Try nearest integer numbers turns ratios
 
*** 5:6 = 6% error
 
*** 5:6 = 6% error

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