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HARDROCK-50 HF Power Amp Kit

HARDROCK-50 HF Power Amp Kit

Regular price $370.00 USD
Regular price Sale price $370.00 USD
Sale Sold out
QSK Option

Now shipping the 10th Anniversary Addition with new black anodized enclosure.

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:

Assembly Instructions/Wiki

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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