Instruction manual for the OM2500 HF shortwave power amplifier with GU84B tube, covering specifications, safety, installation and tuning.
The OM2500 HF Shortwave Power Amplifier uses a Russian GU84B tetrode to deliver up to 2700 W PEP across the 1.8‑29 MHz short‑wave bands. The manual provides detailed specifications, power‑supply requirements, safety devices, and operating procedures.
Key sections cover the control cable connection, mains supply wiring, grounding, cooling system, tuning instructions, fault indications, and important safety warnings to ensure reliable and safe operation of the amplifier.
| Frequency range | 1.8 – 29.7 MHz (incl. WARC) |
|---|---|
| Power output (CW/SSB) | 2500 W |
| Power output (RTTY/AM/FM) | 2000 W |
| Power input | 40‑60 W |
| Input resistance | 50 Ω |
| VSWR (input) | < 1.5:1 |
| Power amplification | typically 16 dB |
| Output resistance | 50 Ω asymmetrically |
| Maximum output SWR | 2:1 |
| Intermodulation distance | 36 dB below nominal power |
| Harmonic suppression | < -55 dBc |
| Tube type | Ceramic GU84B tetrode |
| Anode voltage | 8 × 300 V, 2 A each |
| Dimensions (B × H × D) | 485 × 200 × 455 mm |
| Weight | 38 kg (84 lb) |
The amplifier includes protection against high SWR, excessive anode current, excessive screen current, mistuning, soft‑start overload, and switch‑in blocking, each indicated by dedicated LEDs on the front panel.