Users Manual Solid-State HF/50MHz Band 550W Linear Power Amplifier Model HL-550FX
1. Introduction Thank you for purchasing the HL-550FX. This compact and lightweight desktop HF linear power amplifier has a maximum input power of 1.2kW. Our solid-state broadband power amp technology makes it the smallest and lightest in the industry in its class. Typical output power is 550W (SSB, CW) with the drive power of 65-90W. It is best suited for the DX-pedition use due to its light and compact design. 2. 2-1 Cautions The amplifier is cooled by forced airflow.
2-7 The amplifier has fast acting sophisticated protection circuits. Please note, however, any such actions that cause the same fault to occur repeatedly, will lead to failure of the valuable final power FET transistors. 2-8 Before checking inside the amplifier, be sure to wait a few minutes for the high DC voltage to discharge (monitor Vd meter reading). The potentiometers for RF power detector, protection circuits, FET bias voltage circuit, etc.
3. 3-1 Features Our solid-state broadband design engineers worked to make the HL-550FX, the lightest and most compact 550W out portable HF/50MHz amplifier in the industry. This world-class compact 550W HF amplifier is the easiest to handle and operate anywhere in the world. 3-2 The amplifier’s main PA section includes 4 high power MOS FET VRF150, resulting in 550W (SSB/CW max.) on HF and 50MHz bands. The amplifier’s broadband characteristics require no further tuning once the operating band is selected.
4. Specifications Frequency Band 1.8~50 MHz all amateur bands including WARC bands Mode SSB, CW (RTTY) RF Drive 65~90W typ. (100W max.) Output Power 550W typ. (RTTY 400W max.) Drain Voltage 42V Drain Current 30A max. Input Impedance 50Ω (unbalanced) Output Impedance 50Ω (unbalanced) Final Transistor VRF150 x 4 Circuit Class AB parallel push-pull Cooling Method Forced Air Cooling Multi-meter (F.S.
5. 5-1 AC Line Voltage Although the amplifier is designed to work with both AC 115V (100-130V) and AC 230V (200-260V), for stability we recommend operation from AC 230V. 5-2 The correct AC plug (not included in the package) must be obtained locally due to the AC plug variations worldwide. 5-3 The AC line fuse has been factory preset for 115V use (or as requested by the customer at the time of order). If you wish to change to AC 230V, change the fuse to 8A.
6-A. Front Panel Description 14 13 12 10 11 TOKYO HY-POWER SOLID STATE LINEAR AMPLIFIER ID FAN METER BAND PROTECT POWER OPER . ON AIR O.DRIVE O .VOLT PR FUSE O.HEAT MODEL HL550 FX STBY OFF 1 ①POWER 2 3 4 5 6 7 8 9 : Main power switch to turn AC power on and off. ②POWER (LED) : Green LED lights when power is turned on. ③OPER. OPER. : OPERATE/STAND-BY switch. At OPERATE, the amplifier is ready to go into ON AIR (TX) mode and at STBY, it is on STAND-BY mode.
⑨O.HEAT (LED) : When the PA module temperature reaches 80 deg.C, the LED lights to indicate the protection circuit has worked. (It is necessary for the cooling fan to operate for several minutes to cool the PA module.) (Turn the main POWER switch to off, and then on again to reset the Protection Circuits.) ⑩BAND : Select the desired operating frequency band. ⑪METER : To change the multi-meter scales. Meter reads Pf, Pr, Vd, and Id. ⑫ID (LED) : LED lights when the input drain current is over 20A.
6-B. Rear Panel Description FUSE ANT INPUT AC ALC ADJ STBY ⑭AC POWER ALC GND : AC Mains Socket. Socket for the AC power cord. (Socket is EMI filtered.) ⑮STBY : RCA Jack. Connect the control cable from the ACC terminal (or SEND, TX GND etc.) of the transceiver. The center pin is to be shorted to ground through the relay circuit of the transceiver. The DC current necessary is 5V, 1mA only. ⑯ALC : RCA Jack for ALC Voltage Output.
Inner Layout of HLHL-550FX 550FX Upper View ① RF Power Detector and Send-Receive Switching Relay ② Inter-lock Switch ③ LPF Board ④ Main Power Source Unit ⑤ Sub-Power Source Unit ⑥ Control Board ⑦ Power Amp Unit ⑧ Frequency Detector Board ⑨ Cooling Fan ⑩ AC Fuse 9
7. Connection and Operation This section explains a one-antenna system connected to the transceiver and an external SWR/POWER meter. KFX REAR SIDE TRANSCEIVER ALC ACC (SEN D, TX G ND ) SWR/POWER METER TX ANT ANTENNA ANT ANT INPUT AC STBY HL-1.1KFX ALC REAR SIDE HLHL-550FX REAR SIDE 7-1 Connect AC cord and coax cables as illustrated above. Connect the cable from “SEND” to ACC or the remote terminals of transceiver, where it is marked “SEND” or “TX GND”.
antenna has to be adjusted for lower SWR. As an alternative, an antenna tuner may be inserted. 7-4 Turn the POWER switch on. Turn the BAND switch to a desired operating frequency band. Turn the STAND-BY switch to OPER (operate) position and the amplifier is ready to go. If you key the transceiver with the carrier level set relatively low (such as 20-30W), you will achieve an amplified output signal of a few hundred watts.
8. ALC Connection ALC voltage is available at the terminal marked ALC (RCA phono jack) on the right lower corner of the rear panel. Negative maximum DC voltage of ten volts (-10V) is produced at this terminal when the amplifier is fully driven. This voltage is adjustable with the ALC ADJ. knob located above the ALC jack. Setting ALC voltage properly fed back to the transceiver, we recommend you to keep the maximum output power constant or hold the power at a certain level.
9. Protection Circuits There are five major protection functions in this amplifier. If the amplifier has shut down for some reason, before re-setting, correct the possible cause of the shut down. Turn off the POWER once and back on to reset. 9-1 O. DRIVE (Over Drive / Band Miss-set) When the drive power exceeds the 100W level, the amplifier will shut down to STAND-BY mode (or receive) in order to protect the input side of the power FET’s. This protection might also activate if the band is set wrong.
10. Explanation of Major Circuits Four major circuit blocks are explained in their basic form and using signal flows. 10-1 Main DC Power Supply 10-2 Power Amp/ L.P.F. 10-3 RF Power Detector/ TX-RX Switching 10-4 Control Board 10-1 Main DC Power Supply The main DC power supply feeds the 42V DC power to the final PA stage. It is a state of art, switching power supply with high efficiency. A part of 42V line is converted to 24V using a DC-DC converter and is supplied to the cooling fan.
10-4 Control Board (PC1818) This is the heart of the control signal processing for the HL-550FX. It judges the operating condition of the amplifier, as well as issuing the commands to the peripheral circuits. Various analog signals are processed such as RF drive from the transceiver, RF power signals at various points, DC power supply information, etc. There are ope-amps, various three terminal voltage regulators, GAL logic device etc.
11. Trouble Shooting Failure Possible Cause Solution AC mains not ① AC fuses blown ① Replace with new ones. operating ② AC cord not plugged in ② Plug in securely. ③ Interlock switch lifting ④ Wrong tap used on ③ Screw bolts tightly on the top cover. power transformer ④ Correct primary wiring. primary Can’t enter Transmit mode ① Remote control cable ① Check the cable and connect properly. not connected ② Protection circuits ON ② Check the drive power, antenna SWR. Reset with AC POWER switch.
12. Parts Layout 12-1 Top View (Detailed) 12-2 Top View & Side View 12-3 PA Unit (PC1662V) 12-4 LPF Unit (PC1817), Sub AC Unit (PC1819) 12-5 Frequency Detector Unit (PCS1733), RF Power Detector Unit (PC1821) 12-6 Control Unit (PC1818) 13.
