ANTENTOP- 01- 2008, # 010

Matching Circuit for Tube PA

Sergey Lebedev, UA0UG

Radiolubitel KV- UKV # 3, 1996, page 28.

Published 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 of Russia.

The circuit has good efficiency at upper HF bands and good suppression of the high harmonics.

Parts:

C1, C2: Double Air Gap (gap 1 millimeter between plates) Capacitor.

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).

Simple Design of Antenna RF- Choke

Antenna RF choke  from RV9CPK

Antenna RF choke  from LZ2ZK

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