Xiegu X108G as a SOTA portable rig

Rather than continue using my Yaesu FT-817ND with my homemade amplifier, I purchased secondhand a Chinese made 20w HF transciever, the X108G outdoor OLED model. In principal this is a good rig, it’s not much larger than the 817 and 20w rather than 5w makes a difference – OK it’s not the 35w that my homemade Amp produces on 40m but it’s morr that the 15w it produces on 15m. The difference is small in any case and while the X108G is rated at 20w PEP output it shows a good 20w on a non-PEP reading power meter suggesting it’s true output is likely to be closer to 30w PEP that 20w.
The rig covers Top Band through 10 metres, so no 2m or 70cm but on my SOTA activations, I rarely use those bands in any case.
One major floor is this latest model of the X108G Outdoor, is the switch from TFT to OLED display as the OLED display is INVISIBLE as soon as there is any sunlight at all! I contacted Xiegu about this but once I told them I had bought the unit second hand as a private sale, they stopped replying to my emails. Their warranty ONLY applies when the unit is bought through a dealer and is non-transferrable!
After considering retro-fitting the previous models TFT screen (which has brightness and contrast adjustments), I decided to take a different route by using a Smart Phone based remote control program – PocketRxTx to control and display the X108G settings. The author Dan Thoma YO3GGX was very helpful and I soon had a working configuration for the XIEGU X108G.
There is a problem however – when using the X108G connected to a Smart phone the receive noise level can be drastically raised by EMI from the smart phone.
I have tried screened cables clip-on ferrites and winding the USB cable through a Ferrite core. None of these actions work as the interference is being passed down the wires within the USB cable.
I am glad to report that I have come across a board meant for reducing EMI getting into Audio DAC equipment which works with the X108G link, drastically reducing the level of additional noise.
It is available out of China via eBay – this is the posting on eBay.de – use the ID number on your local eBay site to get the text and price in your language:
Please note, there are two connectors on this board.
An USB-A standard socket which takes the cable from the phone – so the other end of the cable has to be Micro-usb or USB type C depending upon how new your phone is AND the plug that goes into your phone has to have “on the Go” OTG enabled, so that the phgone acts as a host while the X108G is the client.
The second connector looks like a Micro-USB socket in the picture but in fact is a mini-USB socket so the cable from this side to the X108G has to be a Mini-USB to Micro-USB cable with male plugs on each end.

I still await the correct cables, at the moment I have an uneccessary adapter in cicuit so that I can connect everything up and I probably should put the board in a small plastic box to protect it – but the solution works and is not being used on my SOTA activations with the XIEGO TRX.

Good USB Cable:

As the connector on my Smart phone is the new USB-C type not the old micro-USB and also as the Smart Phone has to see a line lifted in voltage in the USB-C plug so that it knows to work as the “host” not the “client” (the so called OTG or On The Go function) I was surpised when a couple of months ago, I came a cross a USB-C to USB-micro cable which was supposed to have OTG wired at the usb-c end. Well for 0.99 UK pence (Euro 1.15) including postage, I decided to order one. It took some time to come (from China) but I am very happy to announce that this cable works AND despite (or perhaps because of) its SHORT length doesn’t seem to transfer the phone-noise into the X108G’s receiver!
Here’s a link to the cable on eBay.
This has been tried out in the shack and will now get tested on some summits – it’s certainly a lot easier to carry than the combinations I have been using!