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
AA6VB Rating: 2021-02-26
Spectacular Amplifier Time Owned: 3 to 6 months.
This is an update to my previous review.

My amplifier has performed flawlessly since it was first built. I was lucky enough to have a friend who let me assemble his kit recently. I noticed a number of useful upgrades.

The LDMOS is now a BLF189XRUA which is rated at 1700 watts vs. the MRF1K50H which is rated at 1500 watts. This means there is about 15 percent more "headroom" when run at the recommended output. The point here is NOT that this amp will generate more power. It won't, due to the input attenuation and the current limit. It's simply that the LDMOS itself has more capability IF the amp were designed to run at a higher power level. The amp REMAINS a 1,000 to 1,200 amp. Do NOT push the amp beyond the recommended power level. It puts unnecessary stress on the other components and shortens their life. The difference between 1200 watts and 1500 watts is only 1dBm.

Also, there is now a master on/off switch on the back of the case, so the power supply fan does not need to run 24/7/365 any longer. Also, a minor point, but the grounding post has been upgraded to a more user friendly type with a wing nut, making it much easier to attach a ground wire.

Finally, there is new software so the new display shows BOTH SWR and Reflected power.

The kit went together easily and the boards continue to be top quality. The amp worked on the first power up.

These amps look great, are easy to build and perform very well.

Kenny has also modified his website so it is super easy to order the kit. No guessing required!

Great job Kenny!

++++++++++++ Previous Review ++++++++++++

Initially I was uncertain as to how to order the kit and what was - and was not - included. A quick email to Kenny (KM3KM) and it was clear that "everything" is included in the kit with the sole exception of the power cord which plugs into the back of the amp. I picked one up on Amazon for $8.00 delivered. Kenny included top quality phono cables to connect the PTT and ALC between the amp and the rig and even programmed my callsign into the display! Kenny pre-loaded all the software to make it easy to get the amplifier up and running.

I also had some questions about how difficult it would be to assemble the amp. Kenny was happy to send me the assembly manual with high definition photographs. Another quick review revealed that each of the modules was preassembled, aligned and tested so assembly would be a simple matter of mounting a handful of connectors and modules in the proper order, and soldering a few inter-connections (including three coaxial cables). Suggestion - place a bit of solder on the PCB Pads "before" you solder the coaxial cables. It makes the process MUCH easier, faster and cleaner. Also, you might want to add lock washers on the screws that attach the AC outlet. Otherwise they might come loose over time and it would be a project to tighten those screws after the power supply has been installed. Not a big deal but worth doing.

Kenny was extremely responsive to my emails, even on a Sunday. Not to jump ahead but he even sent an email asking how the assembly process was going!

When the kit arrived (20 days from the date my order was placed) I was delighted to see all the component parts were extremely well packed and protected. Each module was enclosed in an anti-static protective package surrounded by bubble wrap. The hardware and connecting cables were separated into a few packages making it easy to locate a specific cable or piece of hardware.

An inspection of the individual modules shows Kenny's top notch craftsmanship. The soldering joints were clean and bright. He even premeasured and pre-stripped the interconnecting coaxial cables making the assembly process that much easier!

The amp uses the NXP 1K50H LDMOS capable of over 1,500 watts, so you can run the amp at the recommended 1,000 output without driving the amplifier output beyond linearity. This is the same LDMOS used by SPE in their 1.3K-FA amplifier.

The display is a 7" touch screen made by Nextion which has been around for a few years at least and is rated at in excess of 1,000,000 touches. The screen has excellent reviews and is readily available for a whopping $75.00 on the internet should it require replacement.

The amplifier looks great and weighs only 27 pounds, including the internal power supply, so it is easily portable. The power supply will automatically adjust between 117 and 220 volts. Just make sure you purchase a cord with the proper plug.

Kenny indicated the amp will safely bypass 100 watts in standby. The manual says the amp should not be used in full break-in mode, so keep that in mind. This is not an issue for me as I only use semi-break-in.

The amp has three selectable antenna connectors and defaults to Antenna 1 once power is removed. A great feature is that you can program any of the antenna connectors for A specific band. Say Ant. 1 is a 160 meter vertical, Ant. 2 is an 80 meter vertical, and Ant. 3 is a 40 meter vertical. Press "Auto" and key your rig on 80 meters. The amp will switch to Ant. 2 and you are set to go. Then you can QSY to 40 meters by changing the band on your rig, key the rig, and you are now on your 40 meter antenna. The amp follows along in each case. All of these settings are remembered by the amp. Very slick!

The Amp looks great and the touch screen is crisp, gorgeous and shows a lot of useful information. At $2,500 delivered the amplifier is an exceptionally good value and you will have the satisfaction of having assembled the kit yourself.
KQ9J Rating: 2021-02-18
Simply fantastic! Time Owned: 3 to 6 months.
This is one nice amplifier at a great price! I contacted Kenny several times with questions before I purchased the amp. Kenny was always very quick to respond and very helpful. I pulled the trigger and the amplifier kit arrived in a little over 3 weeks. Assembly was easy and straightforward. I took my time and made sure to do it right and the unit came on and worked fine from the very first time I plugged it in! The display is beautiful and gives you all the information you need. The amplifier is very well protected, and I have made dumb mistakes like TXing into the wrong antenna and it kicks off immediately. Push the reset button and away you go. I run mine on a dedicated 240 volt line and 29 watts of drive gives me 1 KW out on SSB. Around 12 watts of drive gives me 500 out on CW or digital. I have had it up to 1200 watts on SSB and 700 watts on CW and it did fine. If you are looking for a great amplifier with the enjoyment of doing some of the assembly yourself, look no further than this one.
WU6R Rating: 2021-02-06
Fantastic 1.2KW Amp! Fantastic Customer Support Time Owned: 3 to 6 months.
Update 2/6/21: This amp is amazing and the customer support is even better! It effortlessly drives my Elecraft K3S, my Flex 6600M, my ELAD FDM-Duo SDR and even my Apache Labs ANAN-10 SDR. It works seamlessly with my Palstar AT2KD antenna tuner. It will work on 110v or 220v supply voltage with the server quality auto-switching internal power supply. This has been one of my best shack investments so far. Truly impressive performance.

I decided to take a chance by supporting a small U.S.-based company that gets great reviews for quality, price and customer service. When I was looking into the Mercury IIIS amp, I swapped several email with the owner and designer, Kenny, and he quickly answered all my questions and provided me lots of photos and details.

The price was very reasonable and the amp is the latest state of the art technology... and it is built with the highest quality of parts and workmanship. I placed the order on Monday and received the amp on Friday. The packaging for shipping was the most extensive I have ever seen.

Final assembly took about 3-4 hours and his step by step assembly instructions were well laid out. The amp powered up correctly first time and even looks better in person than in all the photos. It is a first class looking and operating 1,200 watt amplifier. I highly recommend Kenny's amplifier if you are willing to take a chance with something that is not a big name brand and support a U.S.-based small business making great, high quality ham radio gear.
CE2WTF Rating: 2021-02-05
Practico Time Owned: 0 to 3 months.
Hola, soy de Chile y agradesco la oportunidad de poder tener en mi poder este Amplificador. Es Practico, sencillo, hace un trabajo excelente. Quein lo confecciona Kenny Martinez KM3KM, una excelente persona, te apoya y ayuda en cada momento desde que se hace la reserva y en el post recepciĆ³n del equipo. Estoy muy contento. Adquiri 2 unidades una para mi y otra para un amigo y tambien esta feliz. Ahora estoy en campaƱa de adquirir otras dos unidades posiblemente. Estodo un tema enviarlos desde Miamia Chile, pero resulto todo bien. El Equipo esta trabajando con Icom IC7300 y antena Hy Gain TH3. Con 15 wats desde Icom emite 700 watts por amplificador. GRACIAS GRACIAS por tan buena maquina. Recomendado totalemente tanto el equipo como la persona que es Kenny.

Saludos desde Chile
N4QNT Rating: 2021-01-30
Wonderful piece of Equipment. Time Owned: 0 to 3 months.
My review for this fantastic Amplifier starts with great service. Being this is not plug-and-play out-of-the-box and taking on a kit build, while in the middle of the assembly process I needed to e-mail Kenny for a couple of touch-up questions, and within 10 minutes he replied.. Wow! Piece of mind to know from start to finish Kenny will be there for support after the sale. After the satisfaction of having a hand in the assembly of the Amp which basically is pretty straight forward, almost like building a high-end computer rig. Case, power supply, boards (pre-calibrated), modular cables, stand off's and hardware. The only solder points (24 total) are the interconnecting pre-tinned coaxial cables, power supply wires to the case power input plug assembly, 4 SO-239 centers leeds, and 2 female RCA interconnector's tabs to the rear relay board, and finally, cable management. The total build time for me was 5 hours.. And the transmit is very clean down to -46 dBm in the Third Order IMD's :) and 1150 watts all day long. Highly recommend the Mercury III S Amplifier.. Search my call sign on YouTube to watch a great mash-up video of the Amp assembly.
KA3IGW Rating: 2021-01-16
Bringing a Dinosaur (Me) into the 21st Century Time Owned: 0 to 3 months.
I've been an amateur radio operator since the early 1980's and an electronics guy since before then. Assembling this kit has made me feel like I have taken a leap bringing me into the 21st century. Sure, you can put it together in half a day, but I took my time learning and updating my knowledge on each component and circuit board and how this beautifully simple kit works. Six days later and I feel like I finally have a handle on the new world. No more tubes and oversized inductors. And to boot, a great solid state amplifier for which I am given excellent on-air reports. Kenny was helpful above and beyond expectations and is offering up a high quality, high workmanship product that is hard to find these days. Plus an old goat has learned some new stuff. Highly recommended not just for what it is but as a benchmark in progress.
KK4X Rating: 2021-01-04
Nice Quiet AMP, easy to see display Time Owned: 0 to 3 months.
Nice Quiet AMP, user friendly,does the job needed for me.
I like it so much I ordered another one for my SunSDR2 DX, current one is used with Kenwood TS 890. Best of 73,
thank you Kenny and Alex for a fine piece of a Amplifier
Tampa Florida
KM4HI Rating: 2020-12-02
First Class HF+6m 1200w Amp Time Owned: 6 to 12 months.
I was looking for a solid state HF+6m amp primarily for 6m WSJTx modes but also as a backup for HF CW & SSB. I contacted Kenny and we exchanged several emails to address my questions. I was somewhat hesitant about a kit project that included flashing the Arduino Nano module. I was concerned how the amp would handle the continuous carrier digital mode of WSJTx FT8 with its 15 sec duty cycle, especially on 6m. After looking at other solid state amp options and reading owner reviews, it became apparent to me that the Mercury III S offered the best bang for the buck. Kenny builds, tests and calibrates the LPF, controller, antenna relay and power modules as a unit prior to shipping. He warrants the modules for one year and his customer service has always been five star response time. The assembly was straight forward. I offered several recommendations to make in the assembly guide, which he graciously incorporated. This was my first major kit build and it worked as advertised on the first power up. The Mercury performed flawlessly on 6m FT8/FT4 during the WW Digi DX contest and in several CW & SSB contests since. You will love the QUIET operation and the colorful 7" touch screen of this mighty 27 lb gem. Seriously considering a second one.
KP4F Rating: 2020-11-22
GREAT AMPLIFIER Time Owned: 3 to 6 months.
Gorgeous amplifier and very well built and easy 1200 watts out at 45 watts drive but I run it lightly at 700 - 800. Super quiet and plenty of ventilation. This amp will be a keeper in the shack with my Icom IC 7610, 7300 and Flex 6400. EXCELLENT AND INCREDIBLE COMMUNICATION WITH KENNY!!!

I have had this amp for a few months now and I LOVE IT. It is so well-made and you can tell they put a lot of effort into the aesthetics, but that's just the beginning. This amp is as feature rich as you want it to be, but is also perfectly happy being used like a simple PTT amp. RF wise it's very solid and I get great signal reports all the time. No ALC feedback is required. It only takes a key input and coax if that's what you have.
I really can't sing my praises of this amp well enough. Just get one. You won't regret it at all.

Initial impressions and tests:
My configuration is IC7610 + Mercury IIIS + LP-100A.
The Mercury IIIS performs exactly or better than expected, very solid and very well build. Packaging were excellent.
Tuning process on a segment of a band is very fast.

User interface is great, Display is sharp and clear, meters are responsive and very fast.
Very fast protection circuits in case of configuration errors.
Fan noise very low even in high power.
Output power is 1kw(+) without any problem.
Best amplifier I have ever owned! Great job Kenny on this product!
VE7ZN Rating: 2020-11-15
Excellent Amp, Terrific Service Time Owned: 0 to 3 months.
I recently acquired one of these kits from Kenny in FL. First off, Kenny is absolutely excellent. Responds to emails promptly and provides superlative service.

My amp kit came very well packaged and complete. The USB key with hi-rez photos, instruction manual etc is a very nice touch. Everything is clearly labeled and he even includes 4" zip ties to "tidy up" the various cables/connections.

Amp went together smoothly on a Saturday morning - took about 4 hours in total. First quality boards and components are used throughout and the fit and finish of the metal cabinet, display mount bracket and all the bits and bobs is first rate. Very well done!

Kenny programs your callsign into the Nextion display so you see it on boot up and in the top right corner when operating. Nice touch. Initial power up and check out went without a hitch. Smooth as silk.

The amplifier is quiet, markedly so. It is early days for me, of course, but thus far I am VERY impressed.

This "kit" represents very good value and compared to some of the other options out there, I couldn't be more pleased.

Thanks, Kenny and Alexander!