Tokyo Hy-Power HL-550fx HF Amplifier
1.8 MHz ~ 28 MHz (160m ~ 10m) + 6m
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.
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.
The amplifier allows operation in full break-in CW mode due to the use of the amplifier’s high-speed antenna relays (made by Panasonic). Is compatible with wide AC line voltage ranging from AC 100V to 260V. Although AC line voltage is automatically selected, be sure to install proper fuse into AC line fuse holder.
For the safety of the operator, an Interlock system is employed. The AC power is shut down if the top cover is removed, and the automated safety interlock is activated.
Theory of Operation
(How It Works/ RF Signal Flow)
When the amplifier is in a stand-by (STBY) mode, gate bias (voltage) to the final FET’ s are cut off. Also input (TX) relay and output (ANT) relay are free(open) from the amplifier. Therefore the signals from the transceiver and/or from the antenna will all by-pass the amplifier.(By-Pass/ Stand-By Mode)
When the amplifier is in an OPER.(operate) mode and keyed by the transceiver, forward gate bias is applied to the final power FET’ s and at the same time input and output relays are closed at the IN and OUT terminals of the amplifier. Consequently the amplifier is ready to work with the designed amplification gain.
RF Drive signal from the transceiver reaches RF IN (J504) of DET (Detector) Unit, PC1821, where input power level is measured. If the in drive power is over 100W, the protection circuit will issue a command of “ Over-Drive” , to shut down the amplifier. DET UNIT also measures the amplified output level of the amplifier. When the ratio of output and input (drive) powers is much lower than the designed value, CONT UNIT (PC1818) will judge that final amplifier is out of order and/or that output LPF (low pass filter) is band miss-set.
Drive signal having passed INPUT DET part will be lead to PC1733, Freq. DET UNIT, where the frequency of the drive signal is counted by IC. If the frequency is between 26.0 and 28.0 MHz, CONT (ROL) UNIT issues the command to shut down the amplifier, according to FCC rule.
Then drive signal reaches the input of PA UNIT, PC1662V. Signal is attenuated by 6 dB attenuator before entering the gates of FET’ s. Four FET’ s (VRF150’ s) form a broad-band parallel push-pull linear amp with a gain of approx. forty (40) times.
Next, the amplified signal will pass through LPF (low pass filter) UNIT, PC1817, where the harmonics are filtered and removed.
Filtered output signal will then go through the OUT DET (output power detector) of DET UNIT, PC1821 to reach RF OUT, J505 (ANT) terminal. OUT DET measures the output power level of the signal. This power level is shown on the analog multi-meter, PF scale (forward power).
This amplifier has two sets of built-in DC power supply units. They are commercially made switching mode DC P.S. that work over the wide AC voltage range, i.e. AC 85V～264V. The DC power supply section is solidly shielded and filtered to avoid the leakage of switching noises over the wide frequency range. ADF1000F48 provides DC42V/20A to the drains of final power FET’ s. KWD15-1212 provides +12V and -12V to the various low voltage circuits and control circuits.
Explanation on Band Inhibit Circuit
(To prohibit 26.0～28.0 MHz)
Drive signal from the transceiver is, at first, received by the (RF) DET UNIT PC1821 and then transferred to PCS1733, FREQ. DETECTOR CIRCUIT. The signal is divided by sixteen (16) through the prescaler IC1, TD7101F. The resulting signal is sent to the IC2, PIC micro processor, where the signal frequency is counted If the drive signal is judged to fall in the band width of 26.0 to 28.0 MHz, IC2 issues the command to open the relay RL1, of which contacts are in series with the STAND-BY (STBY/OPER.) control circuit, as is shown around T/R pin of PC1818, CONT’ L UNIT and STBY, RCA-Jack located at the rear panel of the amp.
Once the STAND-BY control circuit becomes open, the amp keeps stand-by mode and amplifier gain is nil, even if it is driven by out of amateur band signals between 26.0 and 28.0 MHz.
- 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
- Output Power Pf 1kW
- Reflected Power Pr 100W
- Drain Voltage Vd 60V
- Drain Current Id 50A
Input/Output Connectors UHF SO-239
- AC 200~260V, 50/60Hz 7.5A max.
- AC 100~130V, 50/60Hz 15A max.
- AC Consumption 1.3kVA max. when TX
Dimension 232 x 145 x 392 mm, 9.1 x 5.7 x 15.4 inches (WxHxD)
Weight Approx. 9.2kgs. or 20.3lbs.
- AC Power Cord x 1
- Coax Jumper Cable (with PL259’s) x 1
- RCA Plug x 2
- Spare Fuse 8A x 2 (for AC200V line)
- Spare Fuse 15A x 2 (for AC100V line)
- Spare Fuse 15A x 2 (for F202, F203 of PC1662V power amp board)
- Spare Fuse 1A x 1 (for PC1662V power amp board) (miniature fuse)
- Spare Fuse 3.2A x 1 (for PC1819 sub AC control board) (miniature fuse)
- Users Manual
DOWNLOAD HL-550fx Schematics
Users Manual, Block Diagram, Parts List.