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Reviews For: Hardrock-50 HF+6M Solid State Amplifier Kit

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

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Review Summary For : Hardrock-50 HF+6M Solid State Amplifier Kit
Reviews: 72MSRP: 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
More Info: http://www.hobbypcb.com
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
15725
VE7NI Rating: 2014-05-29
Nice amp! Time Owned: 0 to 3 months.
I like running CW QRP and building my own gear. The desire for 25 to 50 watts RF o/p power caused me to do some shopping around for an HF amplifier I could use with my QRP gear.
I also wanted an amp that I could build.
The Hardrock 50 meets all the requirements for my operating. When I wound the toroids, I was too tired and put an extra winding on a couple of them. Once the error was discovered (with a couple of suggestions from Jim), the amp worked perfectly!
I am very pleased with the amp and would recommend it to other QRP operators who want the capability of running a bit more output power from time to time using their favourite QRP rig.
AI5RB Rating: 2014-04-19
Great Amplifier for the KX3 Time Owned: 0 to 3 months.
Assembly was a snap. The fit and finish is solid and beautiful.
Easy and perfect setup/alignment.
Works perfectly with my KX3 cabled to the ACC1. The QSK option is just right for CW!
Full output with 2W in.
The HR50 team was great support during the build - quickly sending a replacement part that I had ruined.
This is a very affordable amplifier for a QRP rig for use as a base station.
KI4EZC Rating: 2014-01-21
Hardrock 50 serial #1180 outstanding Time Owned: 0 to 3 months.
Agreement with common review themes - tough but light, clever, professional case design, small enclosure but large enough to get at all the assembly work, well written complete instructions. It is a completely satisfactory solution for taking QRP power to 50w or more. It is worth a lot more to me than the $270 that I paid for it.
I am not a high experience builder; I place this kit at not as difficult and time consuming as the Elecraft KX1 three bands XCVR built about 9 years ago due to so many small parts are already attached to the HR50’s PCB. There was one skill set that I was not prepared for from standpoint of tools and knowhow - that was the #30 Kynar wire. If I had another chance with the correct wire stripper it would have been a snap. Another knowhow problem was how to lightly tin wire leads on transformers. On four of these components by the time I had my lightly tinned wire ready to go into the PCB, I found my prepared wire a little too large for several of the holes. I made a mess in regard to the kynar wire and tinning to point where the amp did could not pass 100% power up test and Jim V WA2EUJ gladly took my effort and made it work with one day turnaround at my cost of only postage- he promises that everyone gets a working amp. I am very happy with my corrected amp- it delivers spec or better power on all bands that I use regularly 40 - 10m and it passed dummy load test for the rest 160- 6n. With ear phones, I don’t pay attention to the quite T/R standard relays (no QSK upgrade) on CW transmit.
I drive it with 2- 3w with an Elecraft KX3 CW output while using a MFJ 941 manual antenna tuner with the PTT connection. This turned out to be breeze to tune the antenna and switch bands (KX3 automatic band switching on HR50 not implemented yet). I rough set the antenna tuning using the KX3 only for a band, tuning the antenna with the 2-3w, then if I need the amp touch up the tune setting with the amps QRO power. I have worked some dx as far as New Zealand from east Tennessee using a simple dipole less than 30' high with this setup.
The HR50 temperature is safe, starting at room temp of about 65F and going to about upper 80s for normal CW QSO back and forth. I have seen as high as 95f on repeated CQ transmissions. This is well below the 140f that JV recommends as safe limit without a cooling fan. I would expect long winded digital mode to require a small fan later.
I am happy with this KX3/HRr50 as my new main station (replacing 10 yr old IC-718). I plan to use the amp on Field day and try it out on a battery. ki4ezc Fred
M0JMO Rating: 2014-01-04
A 5 Star Kit! Time Owned: 0 to 3 months.
I've blogged about the build of my Hardrock-50 at www.tigerstyle-industries.com so I'll try not to repeat myself too much here.

Cost approximately £250 GBP after shipping and import duty to England. Shipping was fast and included tracking.

The instructions for this kit are fantastic; really detailed and thorough. The kit went together without too much drama. I bust the drill bit on the second to last hole... Luckily all the holes for the transistors had been drilled! The Teflon wire is slippery to work with.

50w on all bands from 80m to 10m... Not tried 160. 6m gives about 30w, but I have a problem with the input SWR (4.6:1), so I must have messed up somewhere.

Apart from that, it works exactly as described. The case is rugged and looks good. A really professional product!

Jim replies to queries via email quickly and politely; seems he really cares about customer service!!

Next stop is to update the firmware again and mod the rear board so I can auto band switch with my KX3 :)

Definitely 5-Stars!

Cheers

Josh
M0JMO
N5LDX Rating: 2013-12-31
Great QRP station addition. Time Owned: 0 to 3 months.
Kit shows quality design and was very easy to follow the step-by-step assembly instructions.
I had a 20/17 meter low output problem due to two wrong SMT capacitors types and low output on 6 meter due to one extra turn (6 instead of required 5) on the 6 meter output filter torod.
Jim Veatch, WA2EUJ, the designer of the amplifier suggested I let him look at the issues and fix the problems. He turned the amplifier around in a day after receiving it and it now puts out 50 watts on 160 through 6 meters with 2.5 watts drive. Great product support from Jim!
The amplifier is just what makes my FT817ND perform when needed during difficult band conditions. I operate the entire portable setup with an endfed antenna with a 9:1 balum, and a small MFJ switching power supply for the FT817ND and Hardrock-50 amplifier.
This will be my QRP protable setup for those remote operation conditions while traveling. The extra power makes this setup work for good and reliable contacts when away from the home station.
KB2NGK Rating: 2013-11-26
Works Great - Good Project Time Owned: 0 to 3 months.
I bought this amp as a compromise, not wanting to spend three times as much for the KXPA100 which was yet to be released, especially considering I will seldom need or use an amp. The kit was complete and pretty straight forward. A pleasure to build.

After building, I had low output on a few bands so I contacted Jim Veatch - designer of this amp. He sent me a couple replacement caps, but after replacing them it appeared that the 5V regulator failed. Could have been my fault but not sure. I sent the amp to Jim who repaired it free of charge. You can't ask for better customer service.

This amp does what its supposed to. 50Watts out with minimal drive on all but 6M - 35Watts on 6M.

Overall - Very pleased.
KJ6PTX Rating: 2013-11-10
Great project and amp Time Owned: 0 to 3 months.
A very enjoyable project. The Hardrock-50 provides enough of a challenge that you feel like you’ve accomplished something without being so complex or time consuming that completion is really in doubt. Especially with the great support and encouragement that Jim Veatch, Curtis from HobbyPCB, and the various forums provide. It’s a good, hands-on way to get more familiar with amp components and design as well as some construction and soldering skills. The excellent online instruction manual is easy to follow, thorough, clear and well illustrated.

The amp itself fills a useful niche: 50 watts, under 3 lbs. and less than $300. It adds that extra oomph, when desired, to a QRP rig. The firmware is upgradeable and extra capabilities are evolving in both hardware and software.
VR2XMC Rating: 2013-10-24
Great amplifier and value for money Time Owned: 0 to 3 months.
During field days, power consumption is always of concern. Therefore, I would choose radios with low standby RX current so that I chose Elecraft KX3. However, the output power from a QRP radio is often around 10 watt. Under difficult communication condition, higher power at 25-50 watt is required.

I decided to go for QRP radio + a small linear amplifier covering HF & 6m. This combination in field day (or ARES) will meet my requirements of:
1. low standby RX current;
2. QRO to 25-50 watt if required

Elecraft produced a very nice small linear amplifier KXPA100 with output 100w for KX3. It is also the only linear with built-in ATU in the market.

Regrettably, KXPA100 is beyond my budget. Furthermore, 100w in portable operation will imply quite a demand of power supply.

I eventually go for the kit HardRock 50 (HR50) which covers 6m and well fit my budget. HR50 also gives me the fun of soldering of which the Elecraft KXPA100 is lack.

The soldering and construction work is straight forward with a well written assembly manual. The construction difficulty is less than building my Elecraft K2(s).

At the final stage of construction, I encountered some small problems in the DC bias alignment. An email to Jim WA2EUJ got prompt and detailed reply. The problems were solved after a few email exchanges. The level of service from Jim is as good as the famous Elecraft support services which I often used to. Jim’s advice was concise and right to the point.

The circuit design, which won the ARRL homebrew award, is really good in terms of quality and component cost control. It conservatively uses 4 x RD16HHF1 MOSFET to deliver 50w. RD16HHF1 is readily available in the Chinese component retail market at around US$4 per piece. Therefore, the concern about replacing an expensive RF components in case of builder’s mistakes is not much. Clearly, the circuit design is so well that it is very difficult to cook the RD16HHF1.

All the surface mount components are pre-installed so that only through hole soldering work is required. The wiring work for band pass filters and RF transformers is quite fun to me. This fun is missed in the recent Elecraft kits which only requires the plug-in of PCB (i.e. no soldering work).

The end product HR50 nicely produces 50w for all HF bands with input power less than 5w. It also gives >35w in 6m as per specifications.

Jim has recently rolled out the firmware 1.4E for HR50. I updated the firmware of my HR50 via the USB port in its real panel

I enjoy very much in building (including soldering work) this small linear amplifier which fits my budget very well. I have no business connection with Jim WA2EUJ but am just a happy customer.

AB6WL Rating: 2013-08-25
Great Amplifier for All QRP Rigs Time Owned: 0 to 3 months.
The Hardrock-50 is a great product, and I can only highly recommend it to enthusiastic kitbuilders and QRP/50W QRO operators. It does involve combining your mechanical construction skills with your electronic construction skills, but it is well worth it. Just take your time as you build it, thinking through each step of the process, and if you have any questions along the way, do not hesitate to email Jim, the designer, via the ARRLHBC yahoo group. Either he or Curtis of hobbypcb.com will send you a quick response. Jim's goal is that every builder end up with an entirely working amp. For example, he promptly sent me some new capacitors when the pre-installed ones happened to have the wrong values. Then, he helped me through some final adjustment problems that I was having, so that now I have a very enjoyable 50W amp with the latest firmware. I use it with five different QRP rigs (with a sixth one and a seventh one soon to be completed as kits). Jim even helped all of us figure out how to obtain a shorter return to receive time, which suits me very well as a strictly CW operator. The bottom line is that the amp is a great design and the support provided by Jim and Curtis is outstanding.
WA5ONL Rating: 2013-01-24
Works fine; a TRUE kit ! Time Owned: 0 to 3 months.
Building this kit was a real adventure! This is NOT your nostalgic Heathkit. You get to wind your own toroids, drill holes, make coax jumpers, etc. I was fortunate to have the help of one of our company machinists in drilling and tapping some of the holes in the chassis/heatsink. This would probably not be a kit that I would recommend to anyone who doesn't have at least a fair knowledge of the things mentioned above, and good soldering skills. I am using the amplifier with the Flex-1500 SDR to get me from 5 watts to 50. This makes a big difference! At present, you have to switch bands on the amp by hand; the designers are working on software to let your rig do this for you. Follow the instructions CAREFULLY and you will be rewarded! Mine worked the first time! There are other amps around, like the Backpacker, for a lot more money. With the experience and test equipment that I have, I decided to have a go at building something myself, and I'm glad I did! Now I have the itch to build something else!
In summary, if you have a QRP rig and want a nice boost in power, and are willing to do some careful assembly, the Hardrock just might be for you too.