xtgabyMar 281 minBuilding a QRO 1/49 transformer for end fed antenna.Used material: - 3 cores Amidon 240-43 - copper wire 1.8 mm diameter - PTFE tube with 2 mm internal diameter and 3 mm outside diameter -...
xtgabyMar 131 minThe Turrin balunUsed material: FT240-43 Schematic: Insertion loss: Return loss: Common mode rejection:
xtgabyMar 71 minGuanella 2 wire balun versus Ruthroff 3 wire balun.Guanella 2 wire Ruthroff 3 wire Schematic: Guanella 2 wire Ruthroff 3 wire Return loss: Guanella 2 wire Ruthroff 3 wire...
xtgabyMar 71 minThe Ruthroff balun (1/1 3 wire version).Used material: AmidonFT240-43 core. Top view Bottom view This is the way I think it should be made. Schematic: Insertion...
xtgabyMar 11 minGuanella balun 1: 1 comparison between two and four conductors.Used material: Amidon FT240-43 cores. LEFT = 2 conductors RIGHT = 4 conductors Left: transmission line with an impedance of 100 ohms....
xtgabyFeb 61 minBuilding and measuring a Guanella 1:4 balun with Wurth cores 74270191For building descriptions, see my previous blogs. Return loss measurements: Insertion loss measurements: Insetion loss @ 14 MHz = 0.2 dB...
xtgabyJan 311 min1/1 Current Balun with 15 turns on Wurth core 74270191 for better low frequency behavior.Insertion loss: Return loss: Common mode rejection:
xtgabyJan 301 min1/1 Current Balun with 10 turns on Wurth core 74270191On both sides, i placed 10 turns teflon wire. Insertion loss: Worst case = 0.09 dB @ 30 MHz. This means a power loss of 2 %. Return loss:...
xtgabyJan 161 minMeasurements on output transformer final amplifier TS440.The TS440 power amplifier is a push-pull amplifier with a very low output impedance. To make a conversion to 50 ohms, a 1/16 impedance...
xtgabyDec 30, 20201 minMeasurments on Kenwood YK-88CN CW Narrow filter.Input / output impedance = 600 Ohms Measuring setup: Transformer impedance ratio = 600 / 50 = 12 I have ended with 3 turns / 10 turns....
xtgabyDec 26, 20201 minMeasurments on muRata CFJ455K 14 Input / Output impedance = 2.000 Ohms Measuring setup: Transformer impedance ratio = 2.000 / 50 Ohms = 40 I started with 2 turns / 13...
xtgabyDec 1, 20202 minAnalysis of a Kenwood TS 440 filter unit.How does it work? Depending on the selected frequency, one of the six available filters is activated. This is done by controlling a relay...
xtgabyNov 29, 20201 minBandpassfilter for 80 meter band (3.5 MHz) with Amidon T50-2 cores.5,5 µH coil versus 55 µH coil. Picture: Schematic: 34 turns = 5.5 µH capacitor is approx. 320 pF. 104 turns = 55 µH capacitor is approx....
xtgabyNov 22, 20201 minBandpassfilter for 40 meter band (7MHz) with Amidon T50-2 cores.Important: only for receivers. This filter can not handle transmitted power. Picture: The Kank 3334 transformer from Toko has on one...
xtgabyNov 19, 20201 minBandpassfilter for 40 meter band (7MHz) with Toko Kank 3334 transformers.Important: only for receivers. This filter can not handle transmitted power. Band pass filters are used to effectively suppress strong...
xtgabyNov 14, 20201 minBuilding an endfed antenne "the sequel".Schematic: For the 40, 20, 15 and 10 meter band, I have shortened the first part of the antenne from 20.40 meters to 20.15 meters. I have...
xtgabyNov 1, 20201 minBuilding an endfed antenne kit (from www.hfkits.nl) with 1:49 transformer.Schematic: Buiding the transformer: 1) drilling the holes 2) Placing the hardware 3) Schematic 4) Winding the transformer...
xtgabyOct 26, 20201 minInsertion loss measurements.FT240-31 ===> FT240-31 FT240-31 ===> FT240-43 FT240-31 ===> FT240-61 FT240-31 ===> FT240-77 FT240-31 ===> FT240-31 FT240-31 ===>...
xtgabyOct 24, 20201 minBalun/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...
xtgabyOct 21, 20201 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...
