Bandpassfilter 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....
Bandpassfilter for 80 meter band (3.5 MHz) with Amidon T50-2 cores.
Bandpassfilter for 40 meter band (7MHz) with Amidon T50-2 cores.
Bandpassfilter for 40 meter band (7MHz) with Toko Kank 3334 transformers.
Building an endfed antenne "the sequel".
Building an endfed antenne kit (from www.hfkits.nl) with 1:49 transformer.
Insertion loss measurements.
Balun/Unun 1/9 ==> 50/450 Ohms.
Revised edition. Building and measuring baluns (Part I)
Insertion loss measurement with FT240-31 and FT240-43
FT240-31 versus FT240-43
A practical way to determine the value of the compensation capacity.
Balun for Delta loop and quad.
50 to 100 ohm transformer for receiving systems.
50 to 75 ohm transformer for receiving systems.
9:1 transformer for K9AY antenna.
Case study, how many turns are needed?
Transformers for receiving antennas.
Building and measuring ununs
Magnetic loop 160 meter.
Magnetic loop 80 meter band.