eBay Bargain to Field Radio: A Repair Story
I recently managed to score a Xiegu G90 on eBay for £295. For those who follow the market, these usually retail for around £379 new. The listing described it as "New, Box Opened," suggesting it was a pristine unit that simply hadn't been used. However, upon arrival, it became clear that there was a reason for the lower price point—the radio was essentially a "brick" in its current state.
Before I could even diagnose the hardware, I had to get the radio to boot properly. The previous owner had managed to get the firmware versions completely out of sync. The main body was running V1.81, but the head unit was stuck on V1.79. this meant that the head and body cannot communicate, leaving the radio unresponsive. (Note: in some cases diffrent firmware can still communicate. Just not in mine of course!)
I downloaded the correct flash utility and firmware from the Xiegu official site. After a few minutes of flashing both components to the same version (V1.81), the radio finally came to life. But the victory was short-lived.
When I tried to test the transmission, the internal Automatic Tuner (ATU) started clicking frantically. No matter what antenna I used, the display showed Infinite SWR. This is a classic symptom of a "common fault" with the G90. The design of the SO239 connector on the back puts stress on a small internal copper wire that bridges the connector to the radio module. Over time, or through vibration, this wire simply snaps.
I didn't take enough photos of my own internal disassembly, so I am using a reference image to show exactly what I found once I got inside. The process involved:
Internal View of the G90 Board - Image courtesy of YO3HJV
Once the board was out, the fault was very obvious. The connection was completely broken. I turned on my soldering iron and bridged the two points with a decently sized blob of solder. I wanted to ensure that this time, the connection was beefy enough to handle any future movement or vibration.
After reassembling everything and double-checking the cable, I powered it on. The tuner now tunes instantly, and the SWR is perfect. It is amazing what a bit of solder can do to a "broken" radio.
A couple hours later in the day I took the G90 to the local park with a receive-only antenna to see how it sounds. The receive quality was absolutely amazing crystal clear signals across the bands.
I am now just waiting on a telescopic antenna to arrive, which was very kindly supplied by Matt G7HMV. Once that arrives, I'll be doing a full portable TX test to see how this eBay bargain performs in the field.
I'm currently running the radio on a rechargable 13v 5Ah Lead-Acid Motorcycle battery which puts out 12.9v on standby and then around 12.4 on TX full power which is quite cool since it is putting out 20w.
I have made a couple good contacts local and DX on just 20w, It is 100% a radio to keep!
If I have any updates I will post them here to help anyone else with a G90!