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Reviews For: Xiegu XPA125B

Category: Amplifiers: RF Power - HF & HF+6M

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Review Summary For : Xiegu XPA125B
Reviews: 8MSRP: 549.95
Description:
100W HF 160m to 6m amplifier, 13.8V input, 2-5W input.
Includes ATU.

Frequency range: 0.5-54 MHz
Maximum output power: 1.8-30 MHz >110W / 50MHz >90W
Maximum ambient operation temp: 131 Fahrenheit(55
Celsius)
Gain: 13 dB (+/-2dB)
Spurious suppression: >50 dB
Supply Voltage: 12-15 Volt DC
Transmit current draw: @ max output 30A
Receive current draw: @ max 700 mA
ATU Frequency range: 1.8-30 MHz & 50-54 MHz
ATU Tuning range: 14-500 Ohm
Dimensions: 10.3 x 6.3 x 2.8 inches (Excluding knobs,
feets, handle etc)
Weight: 5.86 lbs(Shipping weight 8.82 lbs)
Product is in production
More Info: https://www.mfjenterprises.com/Product.php?productid=XPA-125B
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0083.1
W0BNC Rating: 2022-03-21
Works perfectly for my vacation radio needs Time Owned: 0 to 3 months.
When I travel, I always take a QRP HF rig with me for when I want to play radio during downtime, or to active a POTA park. Usually it's the KX2, G90, or the X6100. Not packing the FT-891 around is nice for when I hike in somewhere, but I've always wanted to have a little more power when in the hotel, cabin, or tent.

The XPA125B pretty much solved that problem for me. I can take one of the QRP rigs that takes up little to no room in my pack and go play somewhere in the woods. Later when I'm in my room or tent, I can hook up the amp for the extra punch.

I've used it with all 3 rigs, I always run off a LiFePO4 battery, and it has preformed flawlessly. I have not used to tuner yet, so I can't comment about that. Overall I am very happy with the amp.
K3GO Rating: 2021-12-11
Excellent no frills plain amplifier Time Owned: 0 to 3 months.
Wanted a 100 watt amp for my IC705. Read about the reviews here and decided to give it a try. Many other comments elsewhere told me that it could be a good thing. It is. First what it is not. It is not a KXPA100 Elecraft full QSK amp. It is not consistent gain from band to band. Some bands take a watt or two. Other bands take 3-5 watts to get full output.

What it does well-
No frills semi-break in amplifier. Good for packet (PSK and FT8) You can run your 705 at 1/2 watt or so an have a comfortable 30-60 watts out.
THe tuner is excellent - quiet - quick and tunes everything my KXPA100 can. It can be used standalone or with amp.
Amp is quiet. No fans. I have not run it long enough in a transmit cycle to complain about excessive heat, but if that happens I will put a fan on it and continue .

In summary - for $540 its a bargain. Nice build, good package and solid. If you want a plane amp (Not qsk as the review below outlines) then this is a great little SSB, digital, CW amp for your qrp rig.
I recommend it and I am glad I bought it. I Will be hooking it up to my KX3 in the other radio shack in my home. It will also be the vacation and travel amp when we go to the mountains.
Thanks HRO for the great price.
de John K3GO
VU2JE Rating: 2021-11-15
Brand new amplifier with dead LCD display Time Owned: 0 to 3 months.
Bought a brand new amplifier from Astroradio near Barcelona in Spain, and when i connected it in Mumbai, India I find the LCD screen is dead!! So unusable!
Now it is very expensive to ship it to Spain, and pay return shipping and also have to pay some processing / customs charges (unfortunately required in India)!
I am very upset!
Never have such experiences with Japanese or American products! (or even products made in India)
GM8GIQ Rating: 2020-12-15
WORKS WELL, GREAT TUNER Time Owned: more than 12 months.
Bought it October 2018 and use with my QRP rigs.
Have used with an Anan 10, FT817, Flex1500 and SUNSDR2 PRO.

Measured harmonics and spurious etc. to better than 50dB down.

Used exclusively on MANUAL MODE it is a bit quirky to get running as drive levels have to be set carefully and the FATAL ERROR message can be a bit surprising at first.
As per instructions make sure the PTT input never goes above 3.3V.

I use mostly on FT8.

Display is good showing power in/out and SWR .
Power out is slow to register so not much use on SSB.

Tuner is excellent, its the only auto tuner I have used which will tune my carolina windom on 80M.

Very quite with no fans running.

Only problems I have had are a cracked screen after coming home from a couple of weeks away in the winter but Xiegu eventually sent me a new front panel which was a job to fit however.
Set up on 6M is tricky and I have experienced some overheating on 6 on digi modes so have fitted a fan.

Have tried to get more information about amp from Xeigu with a view to writing a review but not even a reply from them so can't comment on customer support.

Great value solid build amp.
KQ4KK Rating: 2020-10-08
It is not an Elecraft amp Time Owned: 0 to 3 months.
For about two weeks I have been using a ICOM 705 with a XIEGU X125B amp on HF and DSTAR HF Voice. The PTT/ALC line out of the 705 is just a 3.5mm Stereo plug. Tip and Barrel is the PTT line. Pin 2 and ground is the keying line on the 125B. I took an old mouse mini6DIN cable to get Pin 2 and ground out. The 125B manual has stern warning about using high setting to the PTT line. The 705 comes set to low. 1 watt from the 705 on 20m gets about 100-105 watts out of the 125B. The 705 has output voltages to make autotuners tune. The 125b autotuner takes input voltages to move from band to band. However, they do not match. So you have to push the manual band select as you change bands. The size of the 125B is just about .5in larger than the base unit of a 7100 or 706. It does not have any fans. And is limited to 55C. Takes about 16 amps to get a little over 100 watts out. It does work. I don't have any spectral review or such. But good audio report I have received.
Down sides - No fans. I can get near 55C running DSTAR HF Voice at 100 Watts on 20m.
Output varies wildly on different bands, requiring increasing, or decreasing the output power on the 705.
The manual says to tune the 125b auto tuner with the amp in standby and send 5 watts to the tuner to tune. That does work, most of the time. You switch the amp out of standby and on at 5 watts in, the 125b shuts off, or gives all kinds of funny warnings. Remember it takes only 1 watt on 20m to get 100 watts out.
It is not an Elecraft KPA amp. A 100 watt amp with auto tuner for $550 is reasonable. Years ago, when I bought an ICOM AT-180 auto tuner for my new 706, I think I paid over $400.
I have used ICOM 7300s, great radio for the price. I have 2 7100s. And a 7610. What I desired was a ICOM IC-7150C, a upgrade of the 7100 with color screen, DSTAR, SDR Receivers, waterfall, Bluetooth, Wifi, builtin GPS. So the 705 with the 125B is the closest I have got.
PJ7DH Rating: 2020-01-02
Solid build quality, quirky tuner. Time Owned: 0 to 3 months.
I was a bit nervous given previous reviews.
I bought this from HRO to use with my 5W SDR transceiver for occasions when QRP is not enough, and it does the job well enough on SSB and digital.
The build quality is good, very solid feel. The amp easily produces rated power on all the bands I tried. My radio does not have the analog band switching voltage, so I use manual band switching which I don't mind too much. Although it would have been nice to have auto band switch via USB.
The tuner is a bit quirky, unless your starting SWR is over 3:1 you have to initiate a tune cycle by pressing the ATU button for two seconds. The scary thing is when for some reason it doesn't achieve a match. It then flashes FATAL ERROR in big letters, the first time I thought I had blown the amp! However if you just remove carrier and then re-apply carrier I usually find it has matched and nothing is damaged. Actually, idiot proofing seems good. It has certainly survived all my mistakes. I don't know why they used "fatal error" instead of something less scary like "No tune".
I find that the way to get a tune every time is to deselect the amp, tune at 5W from the transceiver, then enable the amp again with the transceiver at the correct power for the band in use.
All my antennas are fairly close to resonant, so I don't know how the tuner would work with random wires etc.
Although you can easily get 100W on all bands, the input needed varies greatly. The amp seems to have almost 3 dB more gain on 15m than 40m for instance.
I can't comment on switching times, it hasn't been a problem on SSB/DIGI and I'm not into CW.
Someone mentioned sluggish ON/OFF but the manual states a 2 second push is required for ON/OFF, so nothing wrong there.
Overall I'm happy with my amp, but I would like to see a software update to fix the quirks and allow band change over USB (CAT over USB).
VA2DV Rating: 2019-12-01
Looks good. That’s it. Time Owned: 0 to 3 months.
Like previous reviewer, I really wanted to like this amp. I bought it direct from China. 4 days and it was in my hands. Wow ! However, it is already on a plane back to Asia. I lost a few bucks in the process but the dealer was honest enough to provide me with a full refund.

The amp would turn on the first time but would not turn on a second time without being unplugged from the power source.
Look to me like some kind of an interupt problem in the firmware as the processor seems to be in a sleep mode even when the device is off.

This amp is advertised as 125w out but I would hardly get 85w into a dummy load with a stiff 30-amps power supply.
At least, I would like to see 100w.

The construction of the cabinet and circuits seems top notch to me but I think this thing is still a prototype.
AE7EU Rating: 2019-05-09
Well built, but a major flaw prevent from being a perfect amp Time Owned: 0 to 3 months.
Alright, I'll have to say for this review, I feel sorry for MFJ being the distributor on this. They have been reasonably responsive, and very helpful, but honestly, the big problem with this thing lies with Xiegu.

I wasn't really able to find much in the way of reviews for this thing, except for a few videos, and what looked like a bad photocopy of the manual. After understanding what I thought I might be getting, I took the plunge and bought one for my KX3, figuring I would need to just make a 2.5mm to Mini-DIN6 cable, the parts for which I had already. For half the cost of the 'pro' amp, seems like a good deal.

My first amp arrived with a cracked screen. I'm guessing thermal stress on the plastic window that is glued into the bezel. After corresponding with MFJ, they simply sent me a new one, along with a return label for the previous. Cool!

First off, the good: This amp seems to be very well built, aside from the issue I initially had. It's all aluminum, the edges are solid, and even if you drop it, you're probably not going to break anything off. Peeking through the ventilation, I can see MCX + coax going across the single board, and what little I can see inside seems fine. The power connector is a little cheesy, 2 wires in a 6-pin housing, but it works. I hooked mine up to an Astron SS-25M power supply, and it powered right up. I then used my KX3 to drive the system, and had intended to build a band interface eventually for the KX3, but just went with manual the first time around. Using a 2kW dummy load, I put the PA into passthrough mode, tested SWR to make sure the ATU on the KX3 was off, and make sure everything was 1:1 for solid connections. Per the manual, I adjusted the power on the KX3 to 1W, and band by band, got it to transmit a full 100W. Some bands required 5W, the most sensitive seemed to be 40m with only ~1.6 or 2W drive needed to get 100W output. The dummy load is actually a 40dB, 2kW bird coaxial attenuator in this case, so the other end went into a 50ohm terminated oscilloscope. I was going to do harmonic measurements/etc on this thing, but that brings me to the bad.

Minor bad, the manual it comes with is like they used a crappy 80's photocopier that was low on toner. Okay, get what you pay for, fine. The other minor bad, I found that sometimes I'd press a button and it felt sluggish for something to happen, e.g. power, etc.

Another thing that worries me, but didn't seem to be an issue and that I didn't fully evaluate is the heatsinking. This thing has a massive heatsink, excellent! Except, it has no fans, and the ventilation seems marginal. I figured there was at least a fan inside, but nothing. Upside, it's quiet. I didn't get to evaluate thermal performance.

The major bad: I began testing the keyshape waveform to get an idea for gross linearity. What I found horrified me. The XPA125B has a HORRIBLE TR delay. I would key a dit from the KX3, and see 10's of ms of 5W RF, then a pulse to 100W. After fiddling with my KX3 and finding the TX RF Delay function, I set it to its maximum, 20ms. I found that even with 20ms RF delay, the TR relay was being hot switched. I wish I could attach an image for this review. Here's where it gets worse: The delay from RF active (TX) to when the relay switched would vary by 25ms or so. So on some dits, I'd get 2-3ms of RF and then the TR switch, and on others, 25-30ms of RF before the TR switch. And this is with 20ms on the KX3 side. I know other transcievers only do 30ms delay maximum (IC7300). It turns out, you will need minimum 50ms TR sequencing to get this system to work. Which, for any kind of reasonable operation, simply isn't going to work with this system. I don't know about you, but I'd rather not risk my KX3's finals nor worry about replacing TR relays in the amp down the road due to hot switching. I also re-verified the functionality of the KX3's TR Relay, and that the relay was switching in a timely manner compared to the RF.

Now, I would like to note: The delay is variable, 25ms to 50ms. Because of the function of the front panel, and because it has a processor-based amp enable, I surmise that the XPA125B has a polling loop, instead of using an interrupt. I think this absolute showstopper problem could be easily fixed with a firmware update to using an interrupt. Which is why I give this a 2 and not a zero. BUT: I've been generous waiting for Xiegu to respond to my inquiry, and I didn't get warm fuzzies from MFJ about their response time either. So I'm going to give the benefit of the doubt and say this is a 2, for now, but I'm still sending this back. But, unless you have an external amplifier sequencer and use that can handle a 50ms+ TR delay, I highly suggest you check Xiegu's webpage (http://www.cqxiegu.com/en/index.php?m=content&c=index&a=show&catid=126&id=420) for a firmware update, and if anyone else can confirm that the firmware update would fix this problem.

If Xiegu won't or can't fix this problem, this review really should be considered a 1. Don't damage your radio.

It's a real shame this is turning out to be a dud. I'm certain the tuner, SWR meters, lowpass filters, and the amplifier design itself is perfectly good and well done (likely based off many years of public knowledge, and the application notes from Mitsubishi), but I'm not risking my radio any further to evaluate this.