The HARDROCK-50 ATU Kit adds Antenna Tuner Unit capabilities directly into the HARDROCK-50 enclosure. This easy build kit with all surface mount components already installed is designed specifically for the HARDROCK-50 and will not work standalone.
Sales price $209.00
Tax amount



Currently out of stock due to supply chain issues.  We expect to have stock again Mid November and will ship orders first in, first out.


Additional functions:

  • 60M band coverage. The ATU has a 60M lowpass filter which provides sufficient attenuation of harmonics for legal operation on the 60M band.
  • Wattmeter mode. The HR50 amp will function as a stand-alone wattmeter reading forward and reflected average power, forward peak power and SWR from 0.1 to 50W.
  • QRP mode. The amp keys up and provides ATU functions but does not engage the power amplifier stage allowing the ATU to function with the exciter barefoot.



The ATU is compatible with the QSK mezzanine board for HR50’s with serial numbers above 1200. The ATU is not compatible with the QSK board that mounts on the bottom cover which was used with HR50’s with serial numbers below 1200. The ATU is not physically compatible with the driver amp, If your operation needs the driver amp we recommend integrating the driver into whatever is driving the HR50 or in its own enclosure.




Frequency Range

160, 80, 40, 30, 20, 17, 15, 12, 10, 6 meter Amateur Radio Bands

Input Power

50W maximum, >1W drive required for tuning

Tuning Range

10:1 nominal (lower on 160 and 6 meters)

DC Power

11-16 Volts, < 0.5 Amps

Network Type

L-network (series L, shunt C); C switchable to input or output

Inductance Range

0-7.5 uH in 128 steps

Capacitance Range

0-1300 pF in 128 steps


Non-volatile storage of up to 343 tuning solutions.

160 – 12 meters every 10 kHz (233 solutions)

10 meters, every 25 kHz (69 solutions)

6 meters, every 100 kHz (41 solutions)


Does not affect the overall HR50 size.


Adds about 1 lb (0.45 kg) to the HR50 amplifier

For more technical info and to download the assembly manual, please visit our wiki at:




Dominic Baines
Thursday, 17 March 2016
Had built a couple of HRD-50 amplifier units for others and . I had but not tried on 6m.