KV –UKV # 3, 1996, page 28.
in Byelorussia, Minsk.
As usual, at a Vacuum Tube PA an output tube is matched
with antenna with help of a p-circuit. It is refer to use switching
inductors or variometer. This matching
circuit can work from 3- 30-MHz without switching inductors. The
circuit is widely known among radio amateurs of 9-0 amateurs region
The circuit has good efficiency at upper HF bands and
good suppression of the high harmonics.
C1, C2: Double Air Gap (gap 1 millimeter between plates)
C3: Air Gap (gap 1 millimeter between plates) Capacitor.
L1: Form Diameter 60 millimeters, wound by wire in
1.2- 2.0- millimeter (17- 12 AWG)
This circuit works good with
Russian vacuum tube like GU50 (1000-V Anode, 100-mA plate current),
GU29 (600-V Anode 180-mA plate current).