  Welcome to the Hardrock-50 power amplifier site! The Hardrock-50 is a complete 5W in, 50W out power amplifier kit. The HR50 is FCC Type Approved for commercial sale and can be purchased at HobbyPCB.com. The HR50 uses 4 Mitsubishi RF16HHF1 power MOSFETs and microprocessor controlled for easy reliable operation. The amplifier is based on Jim Veatch's award winning design developed for the ARRL's 2nd Homebrew Challenge competition and was tested extensively by the ARRL labs for output power, linearity and durability. More than 200 kits have been sold and builders receive excellent support and resources the successfully complete the kit. The HR50 interfaces with popular QRP transceivers like the Elecraft KX3 and Flexradio Flex-1500 to provide additional power when necessary or to act as an intermediate amplifier for driving even higher power amps. The HR50 can be fitted with a 0.5W input 5W output driver amplifier that fits inside the case and integrates seamlessly with HR50's operation allowing it to work with low power SDR kits like the Softrock, Peaberry SDR and others. For CW operators a QSK board is available that replaces the electromechanical relay with fast, silent PIN diode switching. Have a look at the reviews on Eham.net (open in a new window).
NEWS: The new prototypes are up and running! We have assembled and tested two of the latest amp boards one with a relay and one with the new mezzanine QSK board. They are both working fine good power output and mate perfectly with the pre-drilled heatsink. The SMT version of the QSK board also works as advertised, the input SWR is a little high on 6M, just like the through version, but all the other bands you'll hardly notice that it's there. It's also MUCH easier to install. Here's what it looks like (click the image for a full size version), notice the nicely wound toroids from The Toroid Guy:  The Toroid Guy now offers pre-wound toroid kits for the Hardrock-50 For $35 you can get a complete set of prewound toroids for the Hardrock-50. It includes L6 thru L15, the next time I have to build one of these, I'm ordering a set! Ordering infor is on the Toroid Kit page. Thanks to Mychael for providing this excellent service for us. The Hardock-50 is now Type Accepted for Amateur Radio Service FCC ID: RHAHR50 No more 'group buy', the Hardrock-50 is a commercial product. The complete FCC test report is available on the FCC Test Report page. We are updating the Hardrock-50 and a new run of kits will be ready to ship on March 1, 2014. Here are some updates that will be included with the new kits: 1. Drilled and tapped holes professionally machined in the heatsink! No drilling, the only mechanical tool needed is a screwdriver. 2. KX3 Automatic Band Switching right out of the box. No mods to the rear panel board required. 3. New QSK Board that plugs into the amp board and requires no additional coax or signal jumpers. 4. No more cheesy RCA connectors we're moving to RG-316 coax (doesn't melt) and 3.5mm terminal blocks. The
machine shop is charging us for the additional operations but given the
feedback we've received, having the heatsink ready for assembly is
worth the additional cost. We
have sold out of the current Hardrock-50 kits. Starting February 7,
2014 we will be accepting pre-orders for the next round of kits at the
pre-order price of $279. Shipping is expected start on March 1 as fast
as we can get the kits ready. After March 1, the Hardrock-50 amplifier
will be available for in-stock ordering at the new list price of $299.At this point I've seen a few units across my workbench and I've adopted a new test strategy. I adjust the input power until the power output reaches 50W or the power input reaches 5W which ever comes first. Here are some of the results. It works like this, you can expect a solid 50W output 160-10M and about 40W 6M with 5W drive or less. One of the provisions of the FCC rules says that an amplifier must have no more than 15 dB gain. Adding the driver takes the gain to about 20 dB so it can be included in the FCC Type Accepted version. We will still sell the driver as a stand alone kit which you can install in your favorite SDR to increase the drive. The new driver has space for a 5 element LPF on the output, a T/R relay and onboard bias regulator. The latest kits with the bias set for 25mA per MOSFET are really performing well. The latest firmware has also improved the wattmeter accuracy. Here is some sample test data: Serial Number: 1151 Date: 11 Oct 2013
The measurements are taken at 50W out or 5W drive if 50W cannot be achieved. Serial Number: 1140 Date: 24 September 2013
The measurements are taken at 50W out or 5W drive if 50W cannot be achieved. |