Xiegu GPA100 Power Amplifier Review

-- By E.T. Bryant

　

　

The GPA 100-watt power amplifier may seem to be just another power amplifier, but it is much more. It is a high-performance linear amplifier that will allow you to select amateur bands from 1.8 to 54 MHz. There is smart cooling, which will activate the internal fan when the temperature reaches a certain level. It also has intelligent protection with fault and overdrive protection. SWR above 1.5 and over 2 will give a fault and cut transmission. The display gives an accurate reading of your power output and the antenna’s SWR.
 

When you purchase the GPA100, you can have access to the Extended Manual. I found this manual to be an excellent replacement for the manual that comes with the amplifier. This was my first power amplifier, and I was confused over some of the terms and what I thought was a lack of explanation in the original manual. But the Extended Manual does give a complete explanation and much more. Not only does it explain how to connect the amplifier to your radio, but how you can use it with the CE-19 and DE-19 data interface for doing digital communication. I used the amplifier with the G90 and the DE-19, and then tried using it with the G106 and the CE-19. Both radios and data interfaces worked flawlessly for doing FT8 communication and using WSJT-X. I must mention, though, if you are using a CE-19, you will need a 6-pin to 6-pin male cable that is not supplied with the amplifier to connect to the ACC 1 port in the back of the amplifier. The GPA does come with a 6-pin to 3.5mm cable you can use with the DE-19.

　

　

　

The front panel is easy to read and use. Pressing the power button will turn the amplifier on. I usually turn on the amplifier first and then the radio. Holding the power button for about 5 seconds will turn the amplifier off. The ON Air LED will indicate that the unit is on. If you have a transceiver with Bluetooth capability, you can set up the GPA 100 to allow you to make changes to it. If you have an Icom IC-705, you can use Bluetooth from your phone or the 6-pin cable included. Pressing the BT button will allow you to set up Bluetooth and activate it.
Pressing the BYP button will put you in bypass mode, and you can operate your Xiegu G90 at a higher power. But do not forget to change the power back to 5 watts or less when not in bypass mode. Pressing the ATT button will activate the GPA100’s attenuator. This will prevent receiver overload from strong nearby signals. If a fault or error occurs, pressing the INFO button will display the error message. Selecting the AUTO button will allow the radio to select the band, or you can press one of the band buttons for whatever band you are using. If you are not using the AUTO button, make sure you select the appropriate band if you change bands, or you may get some unexpected results.

　

　

On the display, you can see the power output in watts. The speaker icon will light up if the buzzer is operating. Below the POUT is a bar that will also give a visual reading of the power output. When you are operating in SSB mode, the power output may fluctuate while transmitting. In order see a constant power output, try transmitting in AM or FM. On the right, you will see the SWR reading and its bar. The area before the band you are on will display Auto or Manual mode if the AUTO button is off. The voltage reading is the voltage being supplied to the amplifier, not the radio voltage. The amp reading will show how many amps you are using for output, and the temperature reading is the current operating temperature of the amplifier.

　

　

The items on the back of the amplifier are mostly self-explanatory, and for the sake of keeping this review short, I will say they are explained fully in the Extended Manual. However, the ALC, BAND, and KEY need a composite video cable, and the KEY is not for a straight key or paddle.
　

Unlike the XPA 125B power amplifier, which has an antenna tuner, the GPA100 does not have one and must use an external antenna tuner. I found this a bit of a disadvantage, but you can place an antenna tuner between the antenna and the amplifier. Since this amplifier will be used in your Ham Shack, that should not be a problem if you have an external tuner. Also, if you have a Xiegu G90, you cannot tune the radio while connected to the GPA100.
　

I thought another disadvantage was that your radio power has to be 5 watts or below. However, as mentioned, there is a bypass button that will allow you to use the G90 at full power. This was not a problem when I used the amplifier with the Xiegu G106 since its maximum wattage output is 5 watts. As mentioned above, I have used the GPA100 with the Xiegu G106 and the Xiegu G90, and it works very well. I highly recommend that you purchase this amplifier for use with the Xiegu transceivers or the Icom IC-705.

　

　

Above is my configuration with the Xiegu G106. I power the GPA100 with a separate 30-watt power supply below my desk.

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