Xiegu GPA100 Review: Turning a QRP Radio Into a 100 Watt Station

The short answer

Buy the GPA100 if you already own a QRP radio you like, such as an IC-705 or a G90, and you want a 100 watt station without replacing it. Skip it if you do not own the radio yet, because a 100 watt transceiver such as the FT-891 costs about the same as radio plus amplifier and gives you a better receiver into the bargain.

Output power: Up to 100 W on HF, up to 80 W on 6 m
Modes: SSB, AM, FM, CW and digital
Approximate price: Around $433

A 100 watt solid state amplifier for the radios that were never going to get there alone.

QRP to 100 W

Xiegu GPA100 100 W Linear Power Amplifier

Around $433

Solid state HF linear amplifier producing up to 100 watts on HF and 80 watts on 6 metres from a low power transceiver, with seven band manual or automatic band switching and Bluetooth band control for the IC-705.

Check price on Amazon

Specifications

Output power	Up to 100 W on HF, up to 80 W on 6 m
Modes	SSB, AM, FM, CW and digital
Band switching	Seven bands, manual buttons with indicators or automatic band tracking
Wireless control	Bluetooth band control with the Icom IC-705
Protection	High SWR, overcurrent, overheat, low efficiency and overpower protection
Stated compatibility	Xiegu G90, G1M, G106, X108G, X5105, X6100, X6200, Icom IC-705 and other low power transceivers
ALC	Supported where the driving radio supports it
Approximate price	Around $433

Specifications above come from Xiegu's published specifications and the manufacturer feature list for the GPA100. Treat pricing as approximate, since Amazon pricing moves.

What it does well

Takes a 5 watt radio to 100 watts, which is a 13 dB increase, roughly two S units at the receiving end.
Automatic band tracking, and Bluetooth band switching with the IC-705, removes the classic amplifier mistake of transmitting on the wrong band setting.
Built-in protection for high SWR, overcurrent, overheating and overpower, which matters most on exactly the radios likely to drive it.
Broad stated compatibility across the Xiegu range and the IC-705.
Lets you keep a portable radio you already like rather than replacing the whole station.

Where it falls short

An amplifier does nothing for receive. If you cannot hear the station, more transmit power does not help, and this is the most common disappointment with any amplifier.
Running 100 watts needs a supply and wiring sized for it, so the true cost is higher than the amplifier price.
Continuous duty modes such as FT8 stress a compact solid state amplifier. Reduce power and give it airflow.
It will not fix a bad antenna. Adding 13 dB behind a lossy feedline still leaves the loss in place, in both directions.

What more power is worth, and what it costs

Power gains are logarithmic and the ear is not. Going from 5 watts to 100 watts is 13 dB, which is a bit over two S units on a typical receiver, and going from 10 watts to 100 watts is 10 dB. That is a real improvement and it is smaller than most people expect. Work the numbers yourself on the dB and power ratio calculator, and read QRP versus 100 watts for what it means in practice.

Running 100 watts also changes two things that are not optional. The first is the power supply: size it above peak draw on the power supply sizing calculator, not to the amplifier's nominal figure. The second is RF exposure. At 100 watts, with a gain antenna at low height near people, the compliance distance stops being trivial. Run it on the RF exposure calculator and read the RF exposure evaluation guide. Maximum permitted power is set by your licence class and your national regulator, the FCC in the United States, not by the amplifier.

What owners report

Published owner reports are broadly positive on the core function: it does produce close to 100 watts from a QRP driver, the band tracking works, and the protection circuits intervene rather than letting the amplifier destroy itself. Owners pairing it with an IC-705 particularly like the Bluetooth band switching, because it removes the manual step where amplifier accidents usually begin.

The consistent cautions are thermal and electrical. Owners report the amplifier getting hot on sustained digital transmissions and recommend backing off power and improving airflow, which is normal behaviour for a compact solid state design rather than a defect. Several also point out that you need a supply capable of the current draw at full output, and that a supply sized for a QRP radio will not do.

A recurring and honest note from owners: the difference between 10 and 100 watts is real but modest at the other end, about 10 dB. Several say that the same money spent on getting the antenna higher produced a larger change in their signal reports. Check what height would do on the antenna height calculator before you assume power is the answer.

Who it suits

Owners of an IC-705, G90 or similar QRP radio who want more power without a new transceiver.
Field and emergency communications operators who need to be heard on a marginal path.
Operators who already have a good antenna and have run out of easy improvements.
Anyone building a go box around a low power radio who wants a switchable power step.

Who should skip it

Anyone who has not bought the radio yet. A 100 watt transceiver costs about the same in total and hears better.
Operators whose real problem is receive. An amplifier is transmit only.
Anyone running long digital sessions at full output without airflow and a substantial supply.
Anyone with a compromised antenna or lossy feedline. Fix that first.

Alternatives worth considering

Buy This Instead

Yaesu FT-891 HF and 6 m All Mode Transceiver

Around $770

One hundred watts and a genuinely good receiver in one compact box. If you are still choosing a radio, this beats a QRP radio plus an amplifier on both cost and receive performance.

Check price on Amazon

Budget Pick

BJ BJ-300 Broadband HF Linear Amplifier

Around $117

A far cheaper broadband amplifier taking 3 to 5 watts to a claimed 150 watts maximum. Broadband designs have no band filtering, so harmonic output is your responsibility and a low pass filter is not optional.

Check price on Amazon

The Thing You Also Need

Astron RS-35M-AP 13.8 V Linear Power Supply

Around $551

Running 100 watts means supplying it. Twenty five amps continuous with real meters, and a linear design that will not add switching noise to the receiver you did not upgrade.

Check price on Amazon

Keep reading

This review draws on published specifications, manufacturer figures and the consensus of verified owner reviews. We have not tested this product ourselves, and we say so rather than implying otherwise. As an Amazon Associate we earn from qualifying purchases.

Common questions

Questions people ask about this

How much difference does 5 watts to 100 watts actually make?

Thirteen decibels, which is a little over two S units on a typical receiver. That is a genuine improvement and it is smaller than most people expect: a station that cannot hear you at all at 5 watts will often still struggle at 100. Antenna height and feedline quality usually produce larger changes for less money, so check those before treating power as the fix.

Do I need a low pass filter with the GPA100?

The GPA100 uses band switched filtering rather than a single broadband path, which is the safer design, and it includes protection circuits. Regardless of amplifier, spurious and harmonic emissions are the licensee's responsibility, and the rules on them come from your national regulator. If you use any broadband amplifier without band filtering, a low pass filter is not optional.

Can the GPA100 run FT8 at full power?

It can transmit on digital modes, and running it flat out on FT8 for long sessions is asking for trouble. Continuous duty modes give a compact solid state amplifier no rest between transmissions, and owners consistently report heat as the practical limit. Reduce power, ensure airflow, and watch the temperature protection. The same advice applies to the radio driving it.

What power supply does a 100 watt amplifier need?

Considerably more than a QRP radio does. A 100 watt HF amplifier at full output draws current in the same range as a 100 watt transceiver, in the low twenties of amps, and a supply sized for a 10 watt radio will collapse. Budget for a 30 amp supply as a minimum and wire it in heavy gauge cable with proper fusing at both ends.

Is it safe to run 100 watts at home?

It is routine, and it is not automatically compliant. RF exposure limits depend on power, frequency, antenna gain and distance to people, and at 100 watts with a gain antenna at low height the compliance distance can be several feet or more. Run your own numbers, document the evaluation, and follow your national regulator's rules, which in the United States means the FCC's exposure requirements.

Keeping your own cut lengths, SWR sweeps and exposure record? The Station Build & Antenna Planner is the paid version of these pages: 8 printable worksheets you fill in with your own numbers, plus the full PDF, $29.

Disclaimer Researched guidance for planning purposes, not professional engineering, electrical or legal advice. Antenna work, RF exposure, mast and tower work, grounding and battery handling all carry real risk that depends on your specific site and installation. Verify anything safety-critical against current FCC rules, the National Electrical Code and the manufacturer's own documentation, and hire a professional where the job calls for one. We research equipment from published specifications, regulatory documents and verified owner reviews rather than claiming hands-on testing we have not done.