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Reviews Categories | Amplifiers: RF Power - HF & HF+6M | Hardrock-50 HF+6M Solid State Amplifier Kit Help

Reviews Summary for Hardrock-50 HF+6M Solid State Amplifier Kit
Hardrock-50 HF+6M Solid State Amplifier Kit Reviews: 40 Average rating: 5.0/5 MSRP: $260.00
Description: Based on Jim Veatch's winning ARRL Home Brew Challenge II amplifier design, it's been improved and functionality has been expanded to include a new aluminum enclosure with built in heat sink, an LCD display, pre-soldered SMT components, computer control options, software upgradeable, easier to use connectors, and MORE. All software is open source and the unit hackable, including an accessible I2C header to add your own peripherals.

Kit includes 4 PCBs (3 without .5W driver) with all surface mount components professionally installed using a reflow process. Builder only needs to install through hole components; toroidal inductors, relays, transistors, connectors, etc. Also includes professionally machined case with integral heat-sink, all chassis mount components, interconnects and instruction/assembly manual. Supports auto band select (depending on transceiver) and can be driven with 0.5 watts.
Product is in production.
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AB3EN Rating: 5/5 Sep 2, 2016 03:36 Send this review to a friend
Good deal, great support  Time owned: 0 to 3 months
I purchased this for my Elecraft KX3. It fits my needs for mobile operation and integrates with the KX3 seamlessly. My friend who is a retired broadcast engineer and designer suggested I look at this kit. He comment was, after a look at the kit and talking with Jim that the design and execution was first rate. After putting the kit together I can attest to his recommendations but need to add that Jim is gracious and helpful almost to a fault. Due to complications from Chemo I had trouble wiring T1, a note to Jim and a fully wound and ready to be soldered T1 was on its way. Support is outstanding, he will not let you fail.
It is a super way to get 50 Watts out with 2-3 watts drive. Thanks Jim, great job.
KC2NYU Rating: 5/5 Aug 29, 2016 11:39 Send this review to a friend
Outstanding Product  Time owned: 6 to 12 months
I am very pleased with the HardRock 50. I wanted an amp for my KX3 and didn't feel like paying the price for the Elecraft one, when I would only be using it for occasionally for portable ops. The points that sold me where, half the price and half the weight albeit half the power. For how I planned to use it, 50w (it will do more ~55-60) was more than ample. You can get it already built or as a kit. I did do the kit and also got the ATU kit.(ATU board mounts on the bottom of upper half of case, internal to the HR50 case. For me the kit build of both units was a good learning experience, in that it was the most difficult kit I had built to that point. You do have to wind a LOT of toroids- but if you pay attention to detail, it isn't hard. The customer service is "outstanding". Jim WA2EUJ, who originally designed the kit for an ARRL contest, responds very quickly for any questions about building or operation. If you need additional parts, they are sent no questions asked and that takes about a week coming form Florida.
The documentation: kit building manual and the operation manual are of Elecraft quality. The connectivity between the HR50 and the KX3 is very good in terms of band switching and PTT, but I have seen videos of folks using with other radios. I have used it in the field and learned that you need a battery with some amperage to run it. I am using four 3.4V LiPo RC cells, that last me about 3 hours. The small Li-Ion batteries that I use for the KX3 would not run the amp. The small black 12v batteries that come from UPS power supplies that many folks use, do just fine with the HR50. All in all a GREAT product with fantastic customer support. I highly recommend it.
W9NUP Rating: 5/5 Aug 15, 2016 15:56 Send this review to a friend
LOVE IT  Time owned: 0 to 3 months
Works well with my Flex 1500. No assembly issues. Did have one defective component which Jim promptly replaced. Only negative is the front panel lettering is difficult to read looking at it directly. Still rates a "5" with me.
WO9B Rating: 5/5 Aug 5, 2016 08:11 Send this review to a friend
Another Fanboy Review!!  Time owned: 0 to 3 months
No sense in repeating what all the other reviews say. This is a great piece of equipment and very nice kit. And I have zero kit experience, yet was able to go from USPS to on the air in 3 days.

So why spend a the extra $100 over the eBay specials for a 50 W amp? Because this is the real deal. Absolutely you will get 50+ watts output. Absolutely you will get nice clean signal reports with an FCC registered product. Absolutely you will get a piece of gear that can handle operator/equipment failure and not fry on the spot. And finally, absolutely you will get a working amp that is SUPPORTED and SERVICABLE.

This is really good stuff. Oh and the price difference? It's cheaper to buy good once than cheap twice.


VA2SS Rating: 5/5 Mar 18, 2016 15:27 Send this review to a friend
Great product and Excellent support !  Time owned: more than 12 months
I bought the kit AMP + ATU during Hamvention 2015. The building process was quite straight foward. The instruction is well written, and step by step process is also well explained.

I must admit that I had some problem when building the kit.... It was solely my fault... crappy eyes... :-) But I can say for sure that I received a promptly and excellent support from Jim. The communication is excellent !!!

So if you are interested in building this kit, but you are a bit worried, no doubt this kit is not very hard to assemble. And combined with the great support, it will be a success for sure.

The amp + atu works like a charm. With 1W of drive, I have more than 40W output. And with 2.5W of drive, I have over 50W output on all bands. I am getting even near 60W on some bands. I also made the cable to connect my FT-817ND. So now, when chaging band, the amp follow the radio. And when I hit the PTT, the amp keys also instantly. A perfect fit for all QRP radio. The modular integration RADIO + AMP + ATU is quite amazing !!!

I really enjoy the way that you can bypass the amp and use only the atu... the QRP mode. And finally, I can also use the kit acting as a power+swr meter.... so in this mode, the amp+atu is completely bypassed, the amp LCD display is acting as an external power+swr meter.

I must also mentioned that this kit is fully upgradable. The USB port let us upgrade with later firmware, but also control the amp with the need of a PC and a software. CAT commands are also well explained in the manual.

A nice kit that enhenced the experience of your QRP to QRO station! Excellent support !
KS4TL Rating: 5/5 Nov 8, 2015 06:25 Send this review to a friend
Nice kit, fantastic support  Time owned: 3 to 6 months
I was a bit worried I went to assemble this kit - I haven't touched a soldering iron (except for antenna work) in about 30 years. I need not have worried.

All surface mount parts are pre-intalled for you. The directions are clear - not quite to the classic Heathkit standards, but close. PCB quality is first rate.

Best of all is the support from HobbyPCB. When I finished my amp, I went to turn it on - and nothing happened. In frustration, I sent it to Hobby PCB - they found my error (I'd trimmed a lead so close that I broke the solder pad connection), fixed it, and returned the working amp to me the NEXT DAY, with no charge save shipping. The best customer support I've ever encountered in ham radio.

And the amp itself does exactly what it's supposed to do. 3 watts in, 50 watts out, all bands, no issues.

If you have a QRP rig and a soldering iron, and want an amp, get this one.

N3JS (ex-KS4TL)
KI4SVM Rating: 5/5 Sep 30, 2015 18:34 Send this review to a friend
Great Little Amp  Time owned: more than 12 months
When I first saw this amp, the first thing I thought was that it would make a nice amp for portable operations. I had been looking for a small amp to take on my Summits on the Air activations and the Hardrock-50 fit the bill perfectly. I was initially hesitant to buy it because it was a kit and my previous soldering projects had not been too successful. But Jim encouraged me to give it a shot, with the safety net of his support and an open offer to send the amp to him if I ever got in over my head, I figured why not.

I did order the pre-wound toroids, but I am proud to say that the rest of the work is mine! ;-) It was a great learning experience and a whole lot of fun. After finishing the amp, I immediately ordered the ATU and eagerly looked forward to melting some more solder. My only disappointment was that it went together far too quickly and my fun was over in just one sitting.

This amp and ATU has performed very well for me on many outings. It is built like a tank, light enough to throw in the backpack and not too thirsty on the batteries. Exactly what I was looking for!
KE4D Rating: 5/5 Sep 25, 2015 20:38 Send this review to a friend
Excellent  Time owned: 0 to 3 months
I too crossed the wires in L5. Jim diagnosed that via email and then the amp tuned right up. No joy with the ATU. We went back and forth for a few days but the ATU was never recognized by the amp. No five volts at the ATU couldn't find the problem as we were out in our RV and I had minimal gear. Sent the entire unit to Jim. 10 days later I had it back, in perfect working order. A bad SMD compoment and bad 5 volt regulator. 6 days of that 10 was shipping. Great service and the amp os working well. I don't have the interface cable built yet, a project for when I get home from CO next week.
WF2V Rating: 5/5 Jul 11, 2015 12:21 Send this review to a friend
Great AMP, good value  Time owned: 3 to 6 months
Just finished the kit and amp is working great. Only issue was the firmware was incorrect and was causing no TX power and wrong SWR readings. Upgrade the firmware and works perfect now. be sure to make your switch wire longer than the 3 inches it says. also, be sure on/off switch does not short against anything.

Would like the ability to use it on MARS.
AD5HD Rating: 5/5 Jul 4, 2015 12:33 Send this review to a friend
Worth every cent  Time owned: more than 12 months
Easy to build, very easy to adjust. Works very well. Upped the bias to 500mA per FT to get the two-tone waveform to look perfect. Swapped out internal power cable for a 10ga version using 45A Anderson contacts and put a lytic across the Fastons on the board. Drop is about 80mV on xmit. Great on-air reports both by itself and as an exciter for an AL80B. Power and SWR display is pretty accurate compared against an LDG AT1000ProII external meter. Voltage display however reads about 400mV low for some reason, haven't looked into it. Paired with an Elecraft K2 but it helps to have some attenuation in the transmit path so the K2 can run at higher power for best linearity. Broke out the xmit path with RG316 to SMAs on the rear panel and put a 5W 7dB fixed attenuator in line with a 2W 0-10dB variable attenuator to make it easier to run the K2 at about 4-6W while being able to control AL80B output power with the variable attenuator without changing the tune and load settings.
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