2 m PA production OK1VMS


The Power amplifier is intended for contesting and DX SSB/CW operation. Construction utilizes two parallel GI70BT tubes with grounded grid design. Each tube has own setting of grid idle current, independent control of cathode current with balanced high frequency driving power. Anode ”strip-line” circuit is placed in aluminum box. Antenna coupling is capacitive. The SWR meter has two independent circuits showing forwarded and reflected power.

The power amplifier uses AC 230V power supply backed by 10A fuse and further protected with two turn on/off switches. The first switch turns on main transformer, supporting voltages and fun. The first switch has own visual identification. The second switch turns on anode voltage transformer utilizing delayed reaction circuit (limitation of current loop during turns on period). The toroid transformer 2.2kW enables selection of two anode voltages: 2100V or 2400V DC. The presence of anode voltages on tube anodes is signaled by individual glow tube. The fun has relatively silent operation with two running stages (transmitting – receiving).

The power amplifier is controlled either over PTT (63mA) or +TX voltage 7-12V (4mA). Both options are available through 5 pins DIN connector. The control voltage for preamplifier and an antenna relay are available through 5 pins DIN connector, +12V TX, +12V RX, +24V TX, +24V RX. The control supply is limited to 1A maximum current. Both DIN connectors have protection against accidental pull out. On back board are available two permanents supply 12V and 24V DC limited to 1.2A maximum current

The power supply is generally delivered with 50 ohms SO239 (PL type) input connector and 50 ohms output on Russian SR-50 type connector. SR-50 cable connector is supplied.

Maximum power supply: guaranteed 1000 Watts PEP

Power supply gain: 13,4 dB

Dimensions: width 500 mm, height 220 mm, depth 360 mm

Weight: 30 KGs

Special construction amendments and customer requests will be realized after preliminary agreement.


Contact information:

Mr. Miroslav Semerád, OK1VMS

Ph: + 420 281 865 387

Cell +420 724 235 944

Address: V Chaloupkách 57, 198 00 Praha 9, Czech Republic

e-mail: [email protected]