HobbyPCB HARDROCK-50 User manual

HARDROCK-
50
Operating
Instructions
Jim Veatch
WA2EUJ
3 April 2015
50
Instructions

TABLE OF CONTENTS
1. INTRODUCTION ..................................................................................................................................... 1
2. BA IC OPERATION ................................................................................................................................. 2
Connecting the Hardrock-50 Amplifier ............................................................................................................... 2
QRP Transceiver etup: Basic .......................................................................................................................... 3
QRP Transceiver etup: With PTT ................................................................................................................... 3
QRP Transceiver etup: With PTT and Band Data ........................................................................................... 3
DR Transceiver etup: Band Data from Computer ........................................................................................ 4
Using the HR50 as a Driver for a QRO Amplifier ............................................................................................. 4
Operating the Hardrock-50 Amplifier ................................................................................................................. 5
Tuning on the HR50 ......................................................................................................................................... 5
The RX creen .................................................................................................................................................. 5
The TX creen .................................................................................................................................................. 6
afety ................................................................................................................................................................... 7
RF Input Power ................................................................................................................................................ 7
DC Input Voltage ............................................................................................................................................. 7
V WR ............................................................................................................................................................... 7
Temperature ................................................................................................................................................... 7
3. MENU ETTING .................................................................................................................................... 8
Basic Menu Navigation ........................................................................................................................................ 8
Menu Items ......................................................................................................................................................... 9
4. AUTOMATIC ANTENNA TUNER ........................................................................................................... 11
ATU pecifications ............................................................................................................................................. 11
ATU Menu Options ............................................................................................................................................ 11
ATU Operation .................................................................................................................................................. 13
Tuning ............................................................................................................................................................ 13
Recalling tored Tuning olutions ................................................................................................................. 13
QRP Mode ..................................................................................................................................................... 14
5. TRAN CEIVER INTERFACING................................................................................................................ 15
Elecraft KX-3 ...................................................................................................................................................... 15
Yaesu FT-817 ..................................................................................................................................................... 16
Flexradio Flex-1500 ........................................................................................................................................... 17
AE9RB Peaberry DR ......................................................................................................................................... 18
6. ERIAL COMMAND ............................................................................................................................ 19
7. FIRMWARE UPDATE ............................................................................................................................ 22
Installing the U B drivers and Bootloader ........................................................................................................ 22
Updating the Hardrock-50 firmware ................................................................................................................. 23
Updating the ATU Firmware ............................................................................................................................. 24

[1]
1. INTRODUCTION
This instruction manual covers the operation of the Hardrock-50 amplifier. It will cover basic operation, the automatic
antenna tuner (ATU), if equipped, interfacing and operation with various transceivers, serial communications, updating
the firmware and firmware revision notes.
The instructions are based on amplifiers running firmware version 3.0 or later. If you amp does not have at least version
3.0 you can use the instructions in the firmware update section of this manual to install the latest firmware.
The Hardrock-50 (HR50) is a 5W input 50W output linear amplifier designed for use on 160 to 6 meter Amateur Radio
bands. It is FCC Type Accepted for use on frequencies up to 22 MHz. Licensed Amateur Radio operators may use the
amplifier on frequencies up to 54 MHz.
ITEM SPECIFICATION
Frequency Range 160, 80, 40, 30, 20, 17, 15 meter Amateur Radio Bands
Coverage of 12, 10 and 6m available
Input Power 5W maximum, typically 2-3W for full output
Output Power 50W nominal 35W on 6 meters
DC Power 11-16 Volts, 10 Amps typical, 12A maximum
Keying Modes tand-by, Carrier Operated, Push-to-Talk
Input/Output Jacks UHF Connectors
ize 4.25” W by 3.5” H by 7.5” D
(133.4mm W by 88.9mm by 190.5mm)
(not including switches and connectors)
Weight 3 lbs (1.4 kg)
The HR50 can also be equipped with an internal automatic antenna tuner, high-speed diode T/R switching and a driver
amp that lowers the drive requirements to 0.5W or less for full output.

[2]
2. BASIC OPERATION
Connecting the Hardroc -50 Amplifier
Before you can begin using the HR50, you’ll have to connect it to other equipment in your station. Here are the basic
items you’ll need:
•13.8V nominal, regulated DC power supply capable of supplying up to 12 amps of current.
•DC power cable with Andersen Powerpole connectors on the HR50 end, attached to the power supply on the
other end. The HR50 does not have an internal fuse so using an external 15A fuse in the positive lead of the
power cable is a good idea. HobbyPCB.com sells power pigtails for the HR50 amp.
•A QRP radio. The HR50 is designed to work with every QRP radio. Drive levels from 5W down to 20 mW can be
supported. The maximum continuous drive is 6W and no damage has been reported with short bursts of 15-
20W. Putting 100W into the input of this amplifier will damage the amp. The radio connects to the amplifier
using a 50 ohm coax jumper with a PL-259 on the amplifier end and the appropriate mating connector on the
radio end. It is possible to find exact fit replacement connectors for the HR50 so the amp can use BNC or other
popular connectors.
•An antenna. The HR50 primarily delivers power into 50 ohm loads. The amp is tolerant to mismatches consisting
of any passive load from a dead short to an open circuit. The optional ATU can help match a wide range of load
impedances for better power transfer. The antenna connects to the HR50 using a PL-259 connector.
Let’s look at the rear panel:
CONNECTOR
SIGNAL
IN
RF Input, 1.8
-
54 MHz, 0.02
–
5W
from transceiver
OUT
RF Output, 50W nominal 35W on 6 meters
to an
tenna
13.8V DC
DC INPUT, 11
-
16 Volts, 10 Amps typical, 12A maximum
U B
Universal erial Bus connection to PC
PTT
Amplifier keying signal, ground to key, RCA connector
ACC
Various interface signals for transceiver/amplifier communications

[3]
QRP Transceiver Setup: Basic
The HR50 amplifier is connected in between the transceiver and the antenna. The band is selected manually and the
amp keys when RF is detected at the input to the amp (COR mode). For SSB transmissions, be sure to set the COR Hang
Tine for at least 500-1000 msec for smoother T/R action
QRP Transceiver Setup: With PTT
A shielded wire connects the PTT output from the transceiver to the PTT input on the amplifier. This allows the amp to
operate in PTT mode which improves operation for B voice, data and CW Q K modes. The PTT line keys the T/R relay
or the Q K PIN diode switch, whichever is installed in the HR50.
QRP Transceiver Setup: With PTT and Band Data
In this setup the HR50 receives frequency information from the transceiver to automatically select the operating band
and proper ATU channel. The specific detail of this connection is highly dependent on the type of transceiver complete
details are provided in the transceiver interface section of this manual.

[4]
SDR Transceiver Setup: Band Data from Computer
DR software running on a computer can provide band/frequency information to the HR50 amplifier via a U B port.
pecific information about the software and DR’s currently supported is found in the transceiver interface section of
this manual.
Using the HR50 as a Driver for a QRO Amplifier
The HR50 amplifier can be placed between the DR or QRP transceiver and a high power tube or solid state amplifier
allowing the station to produce any power level up to the legal power limit. On the HR50 the PTT line is bridged from the
ACC jack to the PTT jack so high power amplifiers that have DC keying can be tied directly to this line. Older high power
amplifiers that key using AC voltage should be connected with a DC relay. The HR50 has a programmable key-up delay
that can be used to insure that the high power amplifier is online before the HR50 applies RF to prevent ‘hot’ keying.

[5]
Operating the Hardroc -50 Amplifier
Tuning on the HR50
When you first turn on the HR50 the display remains blank for 3 seconds. During this time the HR50 is attempting to
connect with the bootloader. Starting with S/N 1400, the bootloader no longer waits 3 seconds for a connection and the
splash screen appears right away If no connection is made the splash screen is displayed and normal operations begin.
The bottom row tells which version of the firmware the amp is running and, if the ATU is installed, the version of
firmware the ATU is running.
The RX Screen
When the HR50 is not keyed, the RX screen is displayed and the LED is green. On the top row of the display the HR50
shows the currently selected keying mode and band. On the bottom row of the display the HR50 shows the current
heatsink temperature (which can be setup to display in either C or F) and the input DC voltage to the amp.
The KEY MODE button cycles through the various keying modes. OFF > PTT > COR > QRP > OFF

[6]
•OFF – The HR50 will not switch to TX under any circumstances. Any signals applied to the amp pass through
without any amplification or filtering.
•PTT – The HR50 will switch to TX mode in response to grounding the PTT line on the rear panel RCA jack or pin
4 of the ACC jack.
•COR – The HR50 will switch to TX mode when at least 0.1 watts of RF energy is present at the input to the
amplifier. Using COR mode with a SSB transmission can cause the HR50 to key on and off in response to varying
audio level In this case set the COR Hang Time (Menu Item 8) to a higher value or connect a keying line from the
transceiver to the HR50 and use PTT mode
QRP Mode is only available if the ATU is installed
•QRP – The HR50 will switch to TX mode in response to the PTT line being pulled low or RF detected at the RF
input of the amplifier. However the 50W power amplifier will not be engaged so all of the TX displays and ATU
functions are available to the exciter running barefoot.
The BAND ELECT buttons are used to manually select which band the HR50 is operating on. The ‘+’ moves to the higher
band, the ‘-‘ button moves to the next lower band. The band select relays do not change until the HR50 is switched to TX
mode to extend relay life. The BAND ELECT buttons override any external band or frequency information received by
the amp. However new band or frequency information received after a BAND ELECT button is pressed will be
interpreted and update the band/frequency as required.
The 60M band is only available if the ATU is installed The lowpass filter for 60M is located on the ATU board The
amplifier skips over 60M automatically if the ATU is not installed
If UNK is displayed in the BAND portion of the LCD, the amp has received a frequency with is outside the Amateur
Radio bands and the HR50 cannot be put in TX mode until a correct band is selected.
The TX Screen
When the HR50 is keyed by either a PTT or RF signal, the TX creen is displayed. The screen consists of three sections:
•Bar Graphs – The bar graphs display forward and reflected average power, on the top and bottom respectively.
Each segment represents 3 Watts of power. The averaging interval is 1.5 seconds so the display moves very
slowly.
•SWR – The WR area displays the calculated WR provided that the forward power exceeds 10 watts. If there is
less than 10W of average power, the display reads - : - .
•PEP – The PEP section display the instantaneous forward peak envelope power.

[7]
Safety
The HR50 will provide years of reliable service but there are a few areas where it helps to know the amplifier’s limits.
RF Input Power
Most of the input power ends up in four, 1.5W 50 ohm resistors so the HR50 can tolerate 6W input indefinitely and
maybe 10 – 15 watts for short periods of time. The only unit that I know was damaged by excessive input received
100W.
In most cases 5W will overdrive the amp. There generally isn’t 3 dB difference in output when the drive is increased
from 2.5W to 5W which means that the amp isn’t in its linear region. I generally find the 3W is a great level for good
output with low distortion, maybe a bit more if the Q K board is installed.
DC Input Voltage
The amps DC input is rated at 11-16V. All of the components in the amp are rated at least 25V but the dissipation in the
voltage regulator becomes an issue and under some RF loads the MO FETs may see voltages outside their limits with DC
voltages over 16V. Below 11V, the output is reduced and when the voltage is below 9V the relays may fail to engage.
VSWR
The Mitsubishi RD16HHF1 MO FETs used in the HR50 amplifier have a maximum V WR of 20:1 when operated at 16V.
Given that we are operating at a slightly lower voltage and there is quite a bit of circuitry between the MO FETs and the
output jack, there is no passive load that will damage the MO FETs.
Temperature
The Mitsubishi RD16HHF1 MO FET has a maximum channel temperature of 150⁰ C and a thermal resistance of 2.2⁰ C
per watt. In the HR50 the worst case efficiency is about 40% so if the amp is putting out 50W it’s taking in 125W so the
amp is dissipating 75W of those watts, call it 20W per MO FET so there's 20 X 2.2 or 44⁰ C difference between the case
of the MO FET and the channel so we need to keep the case of the MO FET less than 100⁰ C. There's a little resistance
between the case and the heatsink maybe 0.5⁰ C per watt so give it another 10⁰ C and say the MO FETs are safe at
heatsink temps of 90⁰ C.
Heatsink temperatures of 60⁰ C (140⁰ F) are perfectly safe; if you start seeing higher temperatures, consider some forced
air cooling.

[8]
3. MENU SETTINGS
The Hardrock-50 amplifier has a menu system for setting some of the operating parameters. This section covers the
operation of that menu system.
Basic Menu Navigation
To access the menu the amp must be an RX mode. The menu system is unavailable during TX. Press and hold the ‘MODE’
button for 2 seconds and the screen will change to the menu.
To move around the menu items press the ‘+’ and ‘-‘ keys.
When the parameter you want to adjust is displayed press the ‘MODE’ button to select the item.
To change the selected item use the ‘+’ and ‘-‘ keys to show the available settings and press the ‘MODE’ button to store
the new setting.
To exit the menu, navigate to menu item #1 (Exit) and press the ‘MODE’ button. We’ve also made a short cut; pressing
and holding ‘MODE’ for 2 seconds stores the current settings and exits the menu.
I know it’s a bit confusing (we only have 3 buttons to work with) but you’ll get the hang of it. There’s a Youtube video
that shows and early version of the menu that might make it a bit clearer. The menu choices are now expanded and the
exit shortcut hadn’t been implemented yet but you’ll get the basic idea:
https://www.youtube.com/watch?v=Q 7dwe0eYEY
To complicate matters further, not all versions of the amp support all of the menu items. ome items will be missing
from amps with serial numbers less than 1200. If the ATU is not installed, ATU menu setting will not be available.