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Insertion loss measurements.

FT240-31 ===> FT240-31 FT240-31 ===> FT240-43 FT240-31 ===> FT240-61 FT240-31 ===> FT240-77 FT240-31 ===> FT240-31 FT240-31 ===>...

Balun/Unun 1/9 ==> 50/450 Ohms.

FT240-31, FT240-43, FT240-61 and FT240-77 Used material: FT240-31 Start version Tuned version for best SWR (move the coils for best...

Balun for Delta loop and quad.

Use this balun allways in combination with an 1:1 current balun! Schematic diagram: Used material: FT 240-43 Amidon Primary (left): 2...

9:1 transformer for K9AY antenna.

Picture Schematics primary 2 turns secondary 6 turns Used material: 3 cores of 73 material Fair-Rite 2873000202 Input = 2 turns ...

Transformers for receiving antennas.

Used material: 73 material Fair-Rite 2873000202 How to build and measure. 1) One core 2 turns left and 3 turns right. Input = 2 turns / ...

Building and measuring ununs

Remark: all return loss measurements (SWR) are with a light inductive load (adjustable resistor). Real results are always better then...

Magnetic loop 160 meter.

Calculated coil value of the loop is 6.4 uH as explained in de 40 meter band loop. Target frequency = 1.858 KHz Calculated capacity...

Magnetic loop 80 meter band.

Calculated coil value of the loop is 6.4 uH as explained in de 40 meter band loop. Target frequency = 3.700 KHz Calculated value for the...

Magnetic loop 40 meter band.

Alu tube 22 mm diameter lengt = 6 meter ==> diameter loop = 2 meter. Small loop to insert the signal =1.30 meter for best SWR figures. At...

Conversion tables

For people who are not used to work in dB. Loss compared to input signal. VSWR compared to Return Loss (dB