GENERAL DESCRIPTION OF THE OM4000 HF POWER AMPLIFIER
The linear amplifier OM4000HF is designed for all short wave amateur bands from 1.8 till 29 MHz (including WARC) and all modes.
It is equipped with a two pieces of ceramic tetrode FU728F.
Specification of OM4000HF: Frequency Coverage: Amateur Bands 1.8 – 29.7 MHz including WARC Power Output: 4000W in SSB and CW, 3000W in RTTY, AM and FM
Input Power: Usually 60 to 90W for full Output Power Input Impedance: 50 Ohm, VSWR < 1.5 : 1
Power Gain: 17 dB Output impedance: 50 Ohm unbalanced Maximum output SWR: 2:1
SWR protection: Automatic switching to STBY, when reflected power is 350W or higher Intermodulation distortion: 32dB below nominal output Suppression of harmonics: < -50 dBc
Tubes: 2x FU728F Ceramic tetrode
Cooler: Centrifugal blower + Axial blower Power supply: 2 x 230V – 50 Hz one or two phases
Transformers: 2 pcs of toroidal transformer 3kVA Dimensions: 485 x 200 x 455mm (width x height x depth) Weight: 43 kg PROTECTIONS: - VSWR too high - Input power too high - Output power too high - Plate voltage too low - Anode current too high - Screen current too high - Grid current too high - Mistuning of PA - Hot switching protection - Soft start for protecting your fuses - “switch-on blocking “ at opened amplifier
BAR GRAPH INDICATORS: - Power output – 50 LEDs - Reflected power – 20 LEDs - Current at screen ( Ig2 –10 LEDs ) - Anode voltage, anode current, tuning – 30 LEDs LED indicators: - current at control grid ( Ig1 – 2 LEDs ) - WAIT – preheating of tube (180 sec ) - STBY – standby - OPR – operating condition - FAULT – failure, switching off for abt. 4 sec