The new Xiegu GPA100 is a compact, 100 W (on most HF bands) solid-state linear amplifier designed for radio amateurs looking for a portable yet powerful unit for QRP/QRO transceivers. The amplifier covers a wide frequency range from 1.8 MHz to 54 MHz, with an output of 80 W for the 6 m band. This makes it a versatile solution for SSB and digital modes, where signal purity and low distortion are important.
Key technical features and construction of GPA100
GPA100 is built on modern semiconductor (MOSFET) solution with an emphasis on efficiency and low harmonic components - the declared suppression of parasitic components is ≥50 dB. The overall gain characteristics are approximately 14 dB below 29.7 MHz and 12 dB in the 50–54 MHz band, which means that achieving the full 100 W usually requires only a few watts of input power from your transceiver. The physical dimensions are approximately 245 × 164 × 82 mm and a weight of around 2.6 kg - truly a portable "bench" format.
Power supply and operating parameters
The amplifier requires 12–15 V DC (negative ground) and can draw up to 25 A during transmission according to the manufacturer, then only hundreds of milliamps in standby mode. This places demands on a quality source (battery or fixed source with sufficient current reserve) - for longer connections, contest operations, or DX expeditions, it is necessary to consider an adequate power circuit and wiring to minimize voltage drops and thermal issues.
Control, monitoring, and protection
GPA100 offers simple control: physical buttons for 7 bands (1.8-50 MHz) with LED indication of active band and AUTO mode for automatic switching. There is a larger LCD display showing key parameters - output power, SWR, voltage, current, and internal temperature - making it easier to monitor during operation in the shack or in the field. The manufacturer also declares a variety of protective modes: protection against high SWR, overcurrent, overheating, low efficiency, and power exceeding. These functions increase safety during real use with various antennas and in different conditions.
Compatibility and integration with transceivers
GPA100 is designed for easy cooperation with low-power HF devices (QRP) including Xiegu models (G90, X6100, X6200) and popular portable devices like Icom IC-705. ALC support and automatic band switching simplify integration with the transceiver, with modulation and linearity optimized for SSB and digital modes. However, it should be noted that GPA100 does not include an integrated antenna tuner - a separate ATU will be required if you use a poorer antenna PSV. This is a conscious simplification of the concept (lower weight, lower price) compared to some competing models that have built-in ATUs.
Strengths vs. Weaknesses
Among the significant advantages are the power/size ratio (100 W at low weight), a solid set of protective mechanisms, compatibility with QRP devices, and a cost-effective design considering the built-in cooling and monitoring. On the other hand: the absence of an internal ATU, the need for a robust 12-15 V power supply (and feeder cables), and the fact that some retailers still list 'prototype'/early specifications - therefore, I recommend checking the final technical documentation with an authorized distributor before purchasing.
Who is GPA100 suitable for?
This amplifier will be appreciated by portable operators, expeditions, contest operators requiring increased power from a QRP station, and amateurs who need a compact HF amplifier for a car or temporary field station. If you need an integrated ATU or high CW/SSB power (>200 W), then other solutions are more suitable; however, if you want a reliable 100 W 'on-the-go' with modern protections and monitoring, GPA100 is a good choice.
Summary
Xiegu GPA100 offers a balanced mix of portability, power, and features on a smaller budget — 100 W on HF and 80 W on 6 m, protective mechanisms, clear LCD display, and easy-to-use controls.
Source:
[1]: https://www.radioddity.com/products/xiegu-gpa100
[2]: https://xiegu.eu/product/xiegu-gpa100-100W-Solid-state-hf-linear-amplifier