The Hard Rock 50 Amplifier
Hardrock-50 Linear Amplifier
- Works on HF amateur 160m through 6m bands (except that HR-50 has no support for 60m unless the ATU is installed), with drive power and output power in a similar neighborhood. The drive power of both is well suited to the KX3/KX2/FT817/FT818/Icom703/Icom705
- Automatic internal antenna tuner (ATU) available as an extra cost option.
- Powered by 13.8VDC via Anderson Power Poles
- Large finned heatsink on the top, with no fan.
- FCC certified.
- Output power 50W.
- Amp is available in kit form with QSK and with no antenna tuner
Amp with relay switching |
Amp with QSK diode switching |
Amp with relay switching and ATU |
Amp with QSK & ATU |
- With the HR-50, you use the radio power control to control the drive of the amp, and then you can read the output power using the amp’s display while transmitting. If you want to bypass the amp, you push a button on the amp.
- The HR-50 has a data link that goes one direction only.
- With the HR-50, one must select the band manually, or with certain supported trancievers (including KX3/KX2 and Yaesu FT-817), one may use a data cable to have the radio send data to the amplifier to automatically select the proper band.
- The HR-50 has a “Carrier Operated Relay” (COR) mode, where it switches to transmit mode as soon as it detects RF power on the input, and then switches back to receive mode shortly (menu configurable delay) after the applied RF is no longer sensed. This allows interfacing with a tranceiver that does not provide a PTT signal to key the amp.
- The HR-50 also can be placed in conventional PTT signal mode to switch between transmit and receive instead of the COR.
- The HR-50’s ATU also includes a bandpass filter for the 60m band. The HR-50 amp without the ATU does not support 60m.
- The HR-50 has reduced power on the 6m band compared with its power on the other bands.
- The HR-50 can be bought without the QSK option, substituting a slower mechanical transmit/receive relay
- The HR-50 kit assembly involves significant soldering and toroid winding, The soldering for the HR-50 is all through-hole; the boards come with surface mount devices pre-installed and soldered.
- HR-50 has a lighted LCD alphanumeric text display.
- Weighs 3 lbs
- The HR-50 has an available extra-cost add-on for a preamplifier that allows it to be driven to full power with as little as 0.5W drive.
- Firmware is open source and may be modified by the end user.
More information on the Hardrock-50 is available on the HobbyPCB website, hobbypcb.com.