Note
The and TW500A and TW-1000A are broadband, solid-state linear amplifiers manufactured by Trans World Communications, Inc.They have and an output power of 500 and 1000 watts respectively, and cover a frequency range of 2 to 30 MHz.
Core Capabilities
– Operating Modes: Optimized for SSB (voice) operation. An optional FSK configuration is available for high duty-cycle tasks like CW or FSK.
– Broadband Design: Unlike traditional vacuum-tube amplifiers, the TW500A requires no tuning or adjustment during operation.
– Harmonic Filtering: Uses six computer-designed Chebyshev low-pass filters to ensure spectral purity and harmonic rejection.
Features
The units are built for reliability using low-voltage, all-solid-state components:
– Amplifier Sections: Eight 100 watt transistors are arranged in four push-pull sections, providing a power gain of approximately 10 dB. The TW-1000A uses two 500 watt modules.
– Power Supply: An internal, unregulated supply converts 115 or 230 VAC into approximately 14 VDC to power the circuitry.
– Cooling: Features a large, finned aluminum heat sink and an internal fan that activates automatically when the temperature reaches 60°C.
– Safety Features: A high-speed, 75-A magnetic circuit breaker protects against short circuits, overdrive, and antenna mismatches.
– Monitoring: The front panel includes a large meter to monitor total collector current, helping operators ensure the unit is not overdriven.
– T/R Switching: Switching between transmit and receive is handled by grounding a control line, typically linked to the exciter's push-to-talk (PTT) switch. When turned off, the amplifier is completely bypassed.
Specifications
– Frequency Range: 2.0 to 30.0 MHz.
– Power Output: (100) 500 Watts PEP minimum.
– Operating Modes: Standard version is for SSB (voice) only; an optional FSK configuration is available for continuous transmit modes like CW and RTTY.
– Power Gain: Approximately 10 dB.
– Duty Cycle: Continuous for voice (SSB).
– Drive Level (Input): 50 Watts PEP required for full rated output.
– Input Impedance: 50 Ohms, broadband.
– Output Impedance: 50 Ohms.
– Harmonic Suppression: Better than -60 dB, utilizing six computer-designed Chebyshev low-pass filters.
– Intermodulation Distortion: Typically -32 dB (3rd order).
– Internal Voltage: The internal power supply converts AC to approximately 14 VDC to power the RF sections.
Power Requirements: 115 or 230 Vac (internally switchable), 50/60 Hz.
