XIEGU G90 SDR REVIEW

 WEEKEND TEST

With a wet weekend ahead and little danger of the wife dragging me out somewhere I didn't want to go, I thought I'd take the time to have a play around with my latest acquisition - the XIEGU G90 SDR QRP Portable HF Radio.

I'd seen these around the internet and mentioned in the magazines quite a few times and I didn't pay them much attention at all - to be honest, I'd kinda ignored them because I already have the fabulous YAESU FT-818, so what did I need another QRP transceiver for?? Well the truth is, I don't need another QRP transceiver, but what's that got to do with anything? Like most other Hams, I just like getting new radios and experimenting.

The thing that triggered this little purchase was an online conversation with a friend. He'd just acquired one and was telling me about it, so I then started to read/watch a few reviews and discovered that people really did rate this rig - a lot! And it wasn't a scary chance-purchase from China like all those unbranded amps and stuff that you constantly see on eBay. The Xiegu has partnered with MFJ, so it's not going to be an overnight fling.

So soon after, I found one that an old mate was selling one and it was actually brand new in the box and I got it for a saving of £165 on RRP with extras!! How could I say no to that?? In all honesty, I probably wouldn't have bought one at full price because of the 818 sat in my ruscksack, but at this price I just couldn't resist.

Built just a couple of months ago

As you can see from the photo at the top of this post, the radio arrives in a neat, well-padded box containing everything you need to quickly get on air. They even include a programming cable (which many manufacturers charge extra for). The manual is surprisingly well written and contains enough instruction to get you on-air. In all fairness, the radio is surprisingly intuitive to use and there's plenty of really good videos on YouTube to help you get to grips with more technical issues.

I was immediately impressed with the heft and quality of construction - it seemed much nicer built than I'd expected. Mind you, there's some really crummy images of the rig on the internet so that probably effected my judgement previously. Now that I can see it in the flesh and handle it, I have to admit that it's a nice bit of kit. Sure, it doesn't have any sexy contoured styling (it's quite angular and sharp-cornered) but it is still very well presented.

The switchgear is well laid out and most buttons have multiple functions which, like I said earlier, are very intuitive. At the rear of the unit, there is a single SO239 and various ports for a key and other accessories and input/outputs. The power-connector is quite unusual and some people may have never have seen one like it before, but it is actually a common connector in the RC world and is made by Tamiya - very easy to get hold of. And just below that is the GROUND connector which is a nice, easy to use thumb dial - no screwdriver required!

You'll notice from the photos that the radio is fitted with guard rails front and rear. This is another nice touch from Xiegu and something that you normally have to pay extra for. It does seem a little odd though, that they didn't incorporate some sort of folding feet in the design of those rails. They don't even include any rubber feet on the base 😮 

Luckily for me, my radio came with a 3rd party stand which also doubles up as a cooler system. I believe that this cooler is quite a common purchase because the fanless G90 radio may run very hot when transmitting at 20W in CW or DATA modes, so it makes sense to find a way to cool things down. How effective it actually is, I don't know, but judging by the size of the fan, I'd hazard a guess that it's more effective than Yaesu's SMB-201 with it's tiny fan. The fan, by the way, only kicks in when (if) the temperature reaches a certain point (60 degrees)). When running, the fan consumes 150mA.

The fan is unprotected and when you try to pick up the whole unit from the desk, you naturally put your fingers underneath where the blades are. I decided to fit a steel finger-guard which not only protects the blades, but also makes it very easy to pick the unit up.

Apart from providing a cooling system and an adjustable stand, this device also provides connectors for powering accessories. On the side of the unit is a Tamiya connector and an Anderson Pole connector. That's neat!

I also fitted a 12V colour temperature gauge and replaced that plastic VFO knob with a nice metal knob. I think it looks much better and certainly feels better.

Back to the radio - On the right of the G90 is the RJ45 connector for the supplied hand mic. And this is no cheap mic either - it's an Icom type unit with a great range of buttons and it's also illuminated! I remember just how surprised I was when I opened the box of my Elecraft KX3 to find that they didn't even include a microphone even though the radio was £1800!!! Well done Xiegu for not penny-pinching (or yen-pinching).

On the left front side, there's a couple of 3.5mm jack plugs - one for headphones and one for firmware update of the head unit (there's a matching jack plug on the rear of the base unit for programming that). It's not uncommon for separate units to need separate updates. It's worth noting that although the headphones on QRP radios are often heavily used, they may not be so on this radio because it has a fantastic speaker built in, with very good volume levels. Elecraft would do well to take note from Xiegu in this respect!

 

The spec of the radio is really quite impressive, not least of all because of that amazing TFT screen. Yes, it's tiny at just under 2" but so too is the 818's screen. The G90's screen is full colour and razor-sharp! It really is quite impressive and the waterfall and panadapter are fantastically usable even at this size.

The scope has a really fast response time and is an incredibly useful tool to have when working outdoors - and it's a fully active scope too, so you don't have to keep refreshing it. There's limited bandwidth on display, but that suits me fine - if I can see too much of the band at once, I tend to be flicking backwards and forwards all the time.

The receiver covers 0.500MHz through to 30MHz and you can transmit from 10-160M. Some people complain about 6M not being included but personally, that doesn't bother me too much. Operating modes include CW (there's also a great built-in CW Decoder), AM and SSB. A recent update brings FM into the mix too somehow, but I've not done an update yet.

 

It should be noted that there is no provision for internal battery power like there is on the 818 and others. That's disappointing to some operators but not to me because I virtually never use anything other than my 13.2V Zippy FlightMax LifePO batteries when out and about. They're incredibly light and keep their voltage right until the death.

Speaking of voltage, you will probably come across a video where Bob Nagy demonstrates how the Xiegu G90 keeps on pushing out its full power when running on anything from 13.8V down to 10V. That's amazing and makes it so much more usable with different power supplies.

Like my beloved IC-7100, this radio includes a very nice SWR Sweep function. In fact, it's actually better than the 7100. This is one of those features that isn't at all essential, but it sure is nice to have - especially when you can have it without having to lug anything extra with you. The unit also allows you to set an SWR figure at which you want the radio to protect your finals. Maybe you want to play it safe and shutdown at >1.5 or maybe you are happy to go up to 3.0. It's up to you to decide.

The built-in ATU is crazy good at finding a match on virtually any antenna and it does it super quickly!! I always used to praise the Elecraft KX3 for its tuner, but this one is every bit as good. And that's another extra item that you don't have to pay for (or lug around with you like I do with the FT-818).

When active, the ATU pushes out about 7 or 8 Watts even though you may have the TX Power set to 1W. That seems a little odd, but hasn't caused any issues. It's also odd that you cannot set power to zero, so there may be an occasion where you unintentionally transmit into say an Active Receive Only antenna. Again, not a huge problem, but I'd sure prefer the option of being able to set the radio to Zero-Power.

The radio might benefit from a TCXO because the claimed frequency stability is only +- 1.5ppm whereas the FT818 with it's built-in TCXO9 oscillator is +- 0.5ppm. In practise however, I couldn't really detect any drifting.

 

So, now for the actual testing of the radio. 

Nothing scientific - just my old ears. 

I thought I'd give it a quick try on my home QTH EFHW before heading out in the cold damp October weather tomorrow. I connected it to my EFHW and looked on 20M for a signal. There was one at 14.274MHz but that particular frequency was VERY NOISY (quiet either side of this - Sod's Law 😂).

I listened to the operator for a while (IS0FDW) and when a break appeared, I gave him a shout. He immediately came back to me and was very complimentary about my signal and modulation. That's 1800km on a wire from a less than ideal location using half the G90's available power. Not bad.

I spun the dial and listened in on a few more stations across the bands. The G90 has no problem picking up signals and switching between this and my IC-7300, revealed that the only real world difference was the floor noise.  I managed to speak to a couple of UK stations on 40m and got some great signal reports from them too. I also got a few more unsolicited complimentary audio reports. It seemed strange that people went out their way to mention the audio - must be good!

Then I updated the radio to V1.75 and it became even easier to use. Switching to CW, I tuned around for some CW signals to see how well the built-in decoder worked. I don't think any of them are perfect, but I'd say it's every bit as good as the one on the FT-DX3000.

The update process was fairly straight forward as long as you follow the instructions to the letter. There's a point in the update were you have to switch on the radio and then press a key on your computer's keyboard - do it quickly or you'll have to restart the process.

Also, don't be tempted to use another Terminal Program other than the one which is supplied in the Firmware Update Zip File!

Like I said previsously, the G90 is definitely noisier than the 7300 but you wouldn't expect anything else! The filters are quite good once you learn how to trim the Low/High parts of them. This little QRP radio will come into its own in the great outdoors away from noisy urban interference. 

I look forward to getting to the Trough of Bowland with a good dipole this weekend and then I will report back with more experiences of this neat little SDR radio.

73, Tom. M7MCQ.

UPDATE : I was unable to play outdoors due to the UK's horrible weather this weekend. I tried the radio on my EFHW and G5RV and was very happy with the results. Having that panadapter and waterfall will be incredibly handy out in the field and should result in far fewer missed opportunities.

I spoke to quite  few operators from all over Europe and the UK on SSB. I'm sure that I'd have been able to make some Transatlantic contacts too if I'd still been on the radio later in the day. I can't wait to climb a hill and setup a resonant dipole. This radio is a little bundle of fun!

COMMENTS :

Dafydd Gibbon

Very readable review, matches my own experience over the past year. Just a couple of points wrt updating:

- When rebooting, hold down the key WHILE rebooting, don't try to be ultra-fast AFTER rebooting  That's what most of us do.

- There is a very efficient little command line terminal app which Dale Farnsworth wrote for the G90 (search for his name in the Group), originally for Linux and Mac, now for Windows 10. Much simpler and faster than Teraterm.

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73, Tom, M7MCQ.