HARDROCK-50 HF Power Amp Kit


Sales price $299.00
Tax amount

QSK Option



Parts are in stock and we ship first in/first out order.  Most orders ship within a week of ordering but we build kits in batches so if we run out, it could be as long as 2 weeks for shipping.

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 pre-drilled and tapped 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.  The HARDROCK-50 is FCC Type accepted under device ID RHAHR50

Kit includes 3 PCBs 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) via accessory port.


Bands: 160, 80, 40, 30, 20, 17, 15, 12, 10, 6 meter Ham Bands

Input power: 5 Watts

Output power: 40-50W on 160-10M, 30-35W on 6M

DC power: 13.8 VDC (nominal), 10 Amps (max)

Keying modes: COR, external PTT (positive or negative) and Standby

Metering: Forward and reflected power, Temperature, DC Voltage

Size: 4.25” W by 3.5” H by 7.5” D (not including switches and connectors)

Connections: RF In/Out – UHF (SO239); DC Power – Anderson Powerpoles; External PTT – RCA jack; USB serial control; DB9 Accessory Jack

Auto Band Select Support:  Electraft KX3, Various SDRs via PowerSDR over USB, Kenwood CAT compatible devices over RS-232 TTL


Source Code Repository: http://code.google.com/p/hardrock-50/

Assembly Instructions

Support Forum

NOW Available QSK Mezzanine add-on board, Select the option when ordering.  

Please note installing the QSK board in a HARDROCK-50 (or any amplifier up to 50W) does indeed allow the amplifier to be switched in and out very rapidly, 20-25 WPM on CW easily. The QSK board does have an impact on the RF performance of the amplifier when compared to an electrico-mechanical relay. On 160-10M this impact is negligible; 0.25 dB less gain, a few watts less output and 0.25 dB in the RX path none of which are even noticeable. On 6M the story is a little different; 0.5 dB less gain, 5-7W less output, 0.5 dB in the RX path and increased input VSWR. There are certain circumstances where these impairments could have a negative impact on system performance. For weak signal work on 6M with a HARDROCK-50 amplifier, the T/R relay will offer better performance.

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