To Next PageTo Next PageWhat to do if there is no AC power in my QRO Technologies HF-2500DX?
If there is no AC power in your QRO Technologies Amplifier, you can check Fuse F1 or F2 on the rear panel, jumpers on Terminal Block TB1, Transformer T1, On/Off Switch SW2A or SW2B, Interlock Safety Switch SW1, and Solid State Relays SR1 or SR2 or related circuitry.
Why is there no RF output from my QRO Technologies HF-2500DX?
If there is no RF output from your QRO Technologies Amplifier, check for improper connections between the transceiver, amplifier, and antenna.
What to do if the multimeter is inoperative in the High Voltage Function of my QRO Technologies HF-2500DX?
If the multimeter is inoperative in the High Voltage Function, check Resistors R210, R211, R212, R213 on the High Voltage Diode PCB, Multimeter Switch SW501A or SW01B on the Meter Switch PCB, M-1 Multimeter, Transformer T-1 Secondary, and for component failure on the HV Diode or HV Capacitor PCB.
What to do if the ALC is inoperative on QRO Technologies HF-2500DX Amplifier?
If the ALC is inoperative, verify the connection between the transceiver and the amplifier.
What to do if the Grid Trip Circuit is inoperative in QRO Technologies Amplifier?
If the Grid Trip Circuit is inoperative, check the Trip Reset Switch SW6 for defects.
What to do if the multimeter is inoperative in the Plate Current Function of my QRO Technologies HF-2500DX Amplifier?
If the multimeter is inoperative in the Plate Current Function, check Resistors R311 on the LV & Bias PCB, Switch SW401A&B on the Meter Switch PCB, M-1 Multimeter, and Fuse F303 (2 Ampere).
What to do if the multimeter is inoperative in the Screen Voltage Function of my QRO Technologies HF-2500DX?
If the multimeter is inoperative in the Screen Voltage Function, check components on the Screen Supply PCB, Switch SW401A&B on the Meter Switch PCB-510, M-1 Multimeter, and Transformer T-1 Secondary.
What to do if my QRO Technologies HF-2500DX Amplifier will not key when transceiver is keyed to transmit?
If your QRO Technologies Amplifier will not key when the transceiver is keyed to transmit, check the components on the LV & Bias PCB.
Why is the red power LED not functioning on my QRO Technologies HF-2500DX?
If the red power LED is not functioning, check the +12 VDC supply located on the LV & Bias PCB related wiring.
Why is the green transmit LED not functioning on my QRO Technologies Amplifier?
If the green transmit LED is not functioning, check the +12 VDC supply located on the LV & Bias PCB related wiring.
General| Input Power | 100W maximum |
|---|---|
| Power Supply | 240V AC, 50/60Hz |
| Cooling | Forced Air |
| Power Output | 2500W PEP SSB, 2000W CW |
| Output Power | 2500W PEP SSB, 2000W CW |
| Input Impedance | 50 ohms |
| Output Impedance | 50 ohms |
| Gain | 13 dB |
| Harmonic Suppression | -50 dB or better |
| IMD (3rd Order) | Better than -30 dB |
| Frequency Coverage | 1.8-30 MHz |
Details the power transformer, fuses, and soft-start circuit for amplifier operation.
Explains the high-voltage rectifier and filtering circuit for plate voltage supply.
Describes the filament supply voltage and heating requirements for the amplifier tubes.
Details the 12 VAC secondary winding of T2 and its use in DC supply circuits.
Explains the 120 VAC secondary winding of T2 providing isolated supply for the 120 VDC power supply.
Describes the circuits providing cutoff bias and transmit bias for the amplifier's control grids.
Explains the screen grid bias generation using a voltage doubler and zener diodes.
Details the RF input path in standby and transmit modes, including bypass and tuning.
Describes the tube connections, RF driving power, and cooling for the amplifier's tubes.
Explains the tuned output circuit (pi-l network), impedance matching, and harmonic suppression.
Details the ALC circuit function, its control, and how it reduces overdrive.
Explains how screen grid current is measured using meter M-2 and shunt resistors.
Describes the voltage divider and components used to measure plate voltage with meter M-1.
Details how plate current is measured using meter M-1 and a voltage drop across a resistor.
Explains the voltage divider and components used to measure screen voltage with meter M-1.
Describes the keying circuit, T/R relays, and bias relay switching.
Explains the circuit that protects against excessive screen grid current and its reset mechanism.
