Manager - NA4M
Manager Notes

Reviews For: Mercury IIIS HF/6m amplifier

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

eMail Subscription

Registered users are allowed to subscribe to specific review topics and receive eMail notifications when new reviews are posted.
Review Summary For : Mercury IIIS HF/6m amplifier
Reviews: 71MSRP: $2500/kit $2800/assembled
This solid state HF amplifier uses a single LDMOS for
fully automatic operation from 160m to 6M making 1200W with
input power between 50 and 90W depending on your ALC
setting. Protected against antenna SWR over 2 to 1 and
also against excessive input power. Builtin power supply
for 120 or 240 VAC without changing taps in the
transformer, just changing the power cable plug.
Fans work silent and color front panel display. Output to
three antennas selectable in the display with operator
Available as either a kit or starting in early 2022 factory assembled.
Product is in production
More Info:
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
K4IQ Rating: 2021-07-22
Compact and well-designed KW LDMOS amp! Time Owned: 0 to 3 months.
Ordered and received the Mercury IIIs a month ahead of projected date, which was nice! Not much bigger than my first Knight-Kit Star Roamer receiver, the kit is superbly packed and organized to make assembly easy for those with even a little bit of kit-building skill. The trickiest part is soldering the cables and jacks, which is well covered in the included manual and videos. It pays to have a fairly heavy duty soldering iron or gun for making the connections - I had to replace the worn tip on my old gun as it was taking too long to heat.
The amp really fills a "sweet spot" in the available LDMOS amp spectrum, delivering an easy KW across 160-10M and about 750w on 6m. Actual drive required varied across the spectrum, from 15-20W on the 80 and 40m bands, to 25-35W on 160, and also on 20-10m. Six meters needed about 50W drive to reach its max of around 750W. The overcurrent limits are set to prevent output much over 1300W, so I found setting drive levels to achieve about 1100-1200W PEP kept the amp from soft-faulting, which conveniently only requires pushing the screen reset button. CW settings should be a bit less, and continuous duty modes like FT8 are limited to about 700W. The controller also protects against SWR and over-temperature.
The amp is quiet, even with the higher fan speed. The controller activates the max speed fans at 50C on auto, reverting to regular lo speed at 45C. I found that for rag chewing and running DX, it was better to just set for max cooling. The amp does recover well between transmissions. Sound levels were taken, using a Radio Shack sound level meter, and found to be excellent. My Alpha 89, even with its external fan on the rear, has been the quietest amp I've used. The Mercury was quieter on low speed, 53db vs. 57 db. At hi-speed the Mercury came up to 57 db. Very nice!
I ran on 120V for a couple of days until my 240 cable came, and it would still run a KW easily 160-10, so this should be popular as a grab-and-go amp for dx-peditions and field day, etc.
At its attractive price point, and with all these 5 star reviews, the Mercury is rapidly gaining recognition on the air. There is also a companion auto-tuner floating about on YouTube, which promises to make a debut at some point! Highly recommended and congrats to the Mercury team for putting this out for hams to enjoy!
K4DSP Rating: 2021-06-29
Outstanding value Time Owned: 0 to 3 months.
I love this amplifier. Building the kit consists mostly of mechanical assembly with some soldering of cables and connectors. It took me around four hours to assemble it. It worked first time and hasn't given me a minute of trouble since. The amp can put out 1200W on 160-10M with no problem, and around 1.25 dB less on 6M. I measured P1dB at around 1100W, so in the interest of being a good neighbor you will probably want to avoid maxing it out. I run 1000W on CW and SSB with absolutely no problems. For constant carrier modes like FT8 you will need to limit your power output to 700W or less. The amp is protected from over temperature, over current, over dissipation, and high VSWR. I run mine on 240VAC, but the built-in power supply will also work on 120VAC. Be aware, however, that at 750W output the amp draws a little over 15A from a 120VAC line. Keep this in mind when choosing where you'll plug it in.
I've owned a number of tube amps through the years, and most recently a KPA-500 (wonderful amp), but the Mercury IIIS is my favorite so far. I'd buy it again in a heartbeat. 73 de K4DSP
KD1GA Rating: 2021-06-08
Amazing quality and customer service Time Owned: 0 to 3 months.
I was going to pull the trigger on this purchase last summer but when COVID hit I decided against it. Two months ago I decided go for it and so happy I did. I love my AL-80B but seeing nothing but rave reviews on this kit and wanting a solid state amp pushed me to purchase it. I could not be happier, this kit uses nothing but quality components and the over all design and the fit and finish are top notch. The kit itself was a very simple and really fun to assemble. I took my time and completed the build in about 5 hours and after following all the first power up procedures it worked flawlessly. Signal and audio reports were all outstanding. With 30 watts in from the exciter (Icom 7610) the amp easily outputs 1200 watts. This is amazing to me as I had to drive the Ameritron with 70 watts to get 950 out. The Mercury is quiet even if set fans to high speed and the automatic band switching will hopefully help with contesting. Finally, the touch screen is beautiful and provides a ton of good information and control. If you are interested in purchasing a solid state amp for a great price I highly recommend this kit. Kenny and Angel are great to deal with they require 1/2 down and the balance just prior to shipping. They originally quoted a lead time of 90 days and shipped in less than 60.
WD9AZB Rating: 2021-05-31
Excellent experience from start to finish! Time Owned: 0 to 3 months.
What more can I add to what's already been said. The amp quality is superb. The build experience was straightforward, and what's more important - Fun! From pre-tinned coax and solder pads on the circuit boards to the care with which the materials in the kit were packed and shipped, a superior attention to care for the smallest detail is evident.

I was able to put the linear together in less than 5 hours, despite my shaky soldering hand and poor eyesight. The manual guides you step by step. On first power up everything worked perfectly. It puts out over 900 watts on 40 meter SSB with under 25 watts drive, and runs cool and quiet using 120 VAC.

This was well worth the price. The courtesy and service of Kenny and Angel represents the best of the amateur community. This is why I am still a ham and loving the hobby after more than 45 years.
VE2YI Rating: 2021-05-23
Simply excellent! Deserves 5 Star-recognition. Time Owned: 0 to 3 months.
Gorgeous solid-state LDMOS HF kilowatt amplifier - very well designed and easily built and assembled by most anyone, even for the least familiar in assembling any electronic device.

This amplifier comes with all of the boards ready made, tuned and tested. All of the boards are glass-epoxy quality made, with all of the components pre-installed. Nothing to do other than mechanically affix nuts and bolts, solder only a few coaxial cables that are pre-tinned and cut to size, fit the fans, the display assembly, the power-supply and fit the tailor made cabinet together. It's truly a snap to build and simply a pleasure to use.

Auto-detects band and SWR (reflected power), keeps watch and auto protects against Hi-Temp, Hi-current and Hi-SWR very quickly and responsively. Very quite and cosmetically very nice bright full color touch-screen display. It's also equipped with three (3) SO-239 antenna ports on the rear panel, easily user programmed to automatically select the antenna of your choice. Also co-located are two (2) RCA jacks one for PTT and the other for ALC, should you like to use it - although unnecessary other than to protect from over driving should you happen to increase your rig's output power inadvertently.

Spectral cleanliness and linearity is impressive throughout the bands from 160 through 6 Meters. Works flawlessly with my rigs: Yaesu FTDX101D, Flex 6400, IC-7610 and IC-7300. No change or addition of any distortion in Tx audio, and effectively less interference to any adjacent frequency users in comparison to most other amps. (See my QRZ page for a sampling of different model amplifiers I've used, as well as this one now part of my shack!).

Congratulations to Kenny and Alexander for an outstanding design and easily built amplifier!

Remember that you must provide your own regular AC power cord. Also note that the super efficient internal Huawei switching power supply provides the ability to operate at 1KW+ on either 120VAC, as well as 240VAC with no rewiring required (other than changing the plug).
K4PX Rating: 2021-05-09
Great amp and fun to build` Time Owned: 0 to 3 months.
I had not built a kit since a Heathkit around 1965 when I was in high school. I contacted Kenny and Angel and they gave me the confidence to try it. The kit arrived 30 days ahead of schedule and was packaged very well. The manuals, pictures, and videos provided were easy to follow with only a little reading of the tea leaves which is good brain exercise anyway. I turned it on today after spending maybe 5 to 6 hours building it and it works 100% as described. 10 watts in is providing 800 watts out and that is all I need. It will go 1200 watts but I doubt I will go above 800 or so on a regular basis. It is a really cool looking amp and the 7" touchscreen is a killer. Don't hesitate to contact me with questions and by the way my call now is K4PX not N4ZOO and I am good on QRZ. This amp is a 5-star amp and I am going to sell my Expert 1.3K tomorrow. Thank you Kenny and Angel for a great amplifier at a fair price. Very well done guys!
AB5CC Rating: 2021-05-04
Fantastic Quality and Customer Support Time Owned: 0 to 3 months.
Received the amplifier kit on a Saturday after a 57 day wait that seemed like forever. The box and packaging was top quality with no expense spared to protect the contents. Built the kit in a little less than 4 hours. I had one slight issue where I ever so slightly chipped the edge of the Low Pass Filter Board on a bolt from the display bracket while setting it into the amplifier chassis which was my fault (yes, I am the reason all of you got the email warning you to not do that:) and Kenny quickly diagnosed and solved the issue for me. Had it on the air the same evening.

The IC-7300 with the SM-6 desk microphone does not have the microphone click and therefore, just keying the microphone for auto band select doesn't work. So in order to get the auto band/antenna select to work, I just make the slightest blowing sound into the microphone and it selects the band and corresponding antenna perfectly.

Operation is very smooth and predictable. I have always been a band hopper and with the AL-80B, that was not convenient. Now, I can check the bands out and be on the air on a different band in seconds.

This thing is silent on the normal fan speed. I did put the fans on high speed while operating FT8 at 400 watts on 6 meters. The temperature never rose above 37c.

I have just begun to explore all the possibilities with the new amplifier and look forward to many years of fun with this thing. This is the best bargain in amplifiers. Thanks Kenny for a wonderful product.

K0CWO Rating: 2021-04-22
Absolutely wonderful Time Owned: 0 to 3 months.
The kit was delivered around 3 weeks ago at 11 in the morning. Assembly was straight forward and taking my time I had it on the air at 7 PM (that included a break for lunch). I had a question about one of the continuity checks so I wrote an email and I received a phone call from N2PTB in ten minutes who answered my question(s) on the spot. Impressive! I've been running the amp for 3 weeks at about 1 KW out on SSB, it will do 1.2 easily. It works as advertised and compared to other SS amps I have had I am impressed that it isn't as SWR sensitive as all the others. I could go on about this kit but if you are potentially interested in buying one, read the reviews and various forums and you'll get a pretty good idea about what you'll be getting.

Beside the amp, its component quality, design, and good looks, I cannot say enough about the customer service that N2PTB and KM3KM provide.

Absolutely first class!
KA8DSS Rating: 2021-04-11
Very nice amplifier Time Owned: 0 to 3 months.
Just finished building this very nice kit. Excellent fit and finish and easy to build. I feel it is a very good value for the quality components. Would highly recommend. Had one question after using for the first time and my reply was in 20 minutes from the company.
OH2RM Rating: 2021-03-29
Great ! Time Owned: 3 to 6 months.
EDIT 29.3.2021:

Worked the CQ WW WPX with long runs. The amp. worked perfectly for the whole contest, 20hours of operating. 1.1kW PEP out at 40W of drive and temperature stayed below 39C all the time. Look forward to next CW contest

----End of edit---

Easy-to-assemble amplifier kit. Took me 6 hours from start to finish without hurrying up at all. Good instructions.

Started to operate right away and put out 1kW+ at 30W of drive.

Automatic band change makes life easy and as the amp. can take some SWR, most likely not even an ATU will be needed. Makes life easier when compared to a tube amp. with all the tuning procedures.

A small edit to this review: Run my 1st contest with the amp. Easily puts out 1kW on CW with some 20W of drive and does not run hot.

Worked on 14MHZ SSB for several hours with 42W of drive and 1kW PEP output. Again, no signs of overheating or any other issues. My antenna is pretty nicely matched as the forward power is 1kW and returning power is 3W :)

Recommend the M III amp. kit. It is excellent.