xtgaby20 hours ago1 minBalun/Unun 1/9 ==> 50/450 Ohms.Used material: FT240-31 Start version Tuned version for best SWR (move the coils for best SWR) Used material: FT240-43 Start version...

xtgaby4 days ago1 minRevised edition. Building and measuring baluns (Part I) Go to Building and measuring baluns (Part I) and see the results of the guanella 1:4 balun now with teflon insulated wire. FT240-31 with ...

xtgaby7 days ago1 minInsertion loss measurement with FT240-31 and FT240-43I placed an adjustable capacitor between the two cores, and adjusted de capacitor for minimum SWR.

xtgabyOct 151 minFT240-31 versus FT240-43FT240-43 FT240-31 FT240-31 FT240-43 FT240-31 FT240-43 FT240-31 FT240-43

xtgabyOct 141 minA practical way to determine the value of the compensation capacity.I have used an adjustable capacitor with a value between about 5 and 60 pF. Now you can change the capacity until you have the best behav...

xtgabyOct 131 minBalun 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 coi...

xtgabySep 281 min50 to 100 ohm transformer for receiving systems. 5 turns input 7 turns output Used material: 1 core of 73 material Fair-Rite 2873000202 Input = 5 turns / Output = 7 turns 5 squa...

xtgabySep 241 min50 to 75 ohm transformer for receiving systems.4 turns input 5 turns output Used material: 1 core of 73 material Fair-Rite 2873000202 Input = 4 turns / Output = 5 turns 4 square ...

xtgabySep 171 min9:1 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 ...

xtgabySep 31 minCase study, how many turns are needed?Picture Schematics Number of turns left = number of turns right. L value: XL value @ 1 MHz 1 turn: 0,02 mH 125 Ohms...

xtgabyJul 291 minTransformers 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 /...

xtgabyJun 12 minBuilding and measuring ununsRemark: all return loss measurements (SWR) are with a light inductive load (adjustable resistor). Real results are always better then sta...

xtgabyMay 311 minMagnetic 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 valu...

xtgabyMay 301 minMagnetic 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...

xtgabyMay 271 minMagnetic 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...

xtgabyMar 281 minBuilding and measuring baluns (Part II). Another approach 1 core instead of 2. Return loss measurement: Left: FT 240-43 Right: FT140-43 Insertion loss measurement: The me...

xtgabyMar 151 minConversion tablesFor people who are not used to work in dB. Loss compared to input signal. VSWR compared to Return Loss (dB

xtgabyFeb 231 minHow to measure the impedance of a transmission line?If you have a transmission line (coax or open line) with an unknown impedance, I will explain here how to measure this. Above: far end of...

xtgabyFeb 92 minBuilding and measuring baluns (Part I).The 1: 4 Guanella current Balun with FT240 - 31 core. Material used: FT240-31 (outer diameter is 2.4 inch material = 31) Just Google FT24...

xtgabyOct 27, 20192 minEngine rebuild Yamaha SR500Empty left part of the engine. Start in a clean environment and be sure that all rests of old gaskets are removed. Place the bearings, us...