HobbyPCB HARDROCK-50 User manual

HARDROCK-
50 Automatic Antenna Tuner
Assembly Instructions
Jim Veatch
WA2EUJ
3 March 2017
50 Automatic Antenna Tuner
Assembly Instructions
– Rev D.
50 Automatic Antenna Tuner

TABLE OF CONTENTS
1. INTRODUCTION ..................................................................................................................................................1
2. SPECI ICATIONS ..................................................................................................................................................3
3. ASSEMBLY OVERVIEW ........................................................................................................................................4
4. ATU INVENTORY .................................................................................................................................................5
5. INDUCTORS AND TRANS ORMERS .....................................................................................................................7
6. ATU PCB ........................................................................................................................................................... 12
7. RETRO IT ( OR HR50 AMPS BELOW S/N 1400) ............................................................................................... 17
8. INTEGRATION .................................................................................................................................................. 18
9. IRMWARE UPDATE ........................................................................................................................................ 22
Installing the USB drivers and Bootloader ........................................................................................................... 22
Updating the Hardrock-50 firmware ................................................................................................................... 23
Updating the ATU irmware ................................................................................................................................ 24
10. SCHEMATIC DIAGRAM ................................................................................................................................. 28

1
1. INTRODUCTION
Congratulations on your purchase of a Hardrock-50 automatic antenna tuner kit. The ATU is designed to
match antenna loads ranging from 5 to 500 ohms on the 80-10M bands with smaller matching ranges on
the 160M and 6M bands. The ATU is fully integrated with the Hardrock-50 power amplifier and stores
tuning solutions either by the selected band or the specific frequency (if the transceiver is sending the
HR50 frequency data). The data repository for the ATU can be found at:
https://sites.google.com/site/hr50atu/
Construction and installation of the ATU assumes that we are starting with a fully functioning and
testing Hardrock-50 amplifier. If your amplifier does not work please troubleshoot it first, adding the
ATU is not likely to clear up any issues and is likely to complicate the troubleshooting procedure. You
will also need to update the firmware in the HR50 amplifier and quite possibly the ATU as well.
Instructions are provided in section 9 of this manual. I occasionally get asked “If I just bought the unit
last week, why doesn’t it have the latest firmware?” This is because we buy the microprocessors from
the manufacturer with the firmware already programmed so the version of the firmware was current
when we ordered the processors, not when we shipped the kit.
Adding the tuner and upgrading the firmware in the HR50 will enable the following 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. Contact technical support (me) [e-mail] if you need help
with this.
Spare Part Policy
We understand that building a kit for the first time builder may have difficulty with some of the steps
and would find it easier and do a better job if they could do it a second time. To that end if you need
more wire, another core, hardware or anything just send an email and we’ll send a replacement. Spare
parts are included with the kit; we don’t know which ones you’ll need so we can’t put them in the box.

2
Contract Manufacturer Yield
The printed circuit boards in the HR-50 are fabricated, assembled and tested at a contract manufacturing
facility in China. The bare PCB’s are 100% electrically tested before the parts are put on. The
manufacturer that we use to put the parts on the PCB’s reports an 85 – 95% yield when assembling a
board. This means that about 1 in 10 boards will have some manufacturing defect with the SMT
assembly. This usually shows up as an unsoldered component. Since we can’t test the boards before we
send them out it means that there is a chance that we will have to find and repair something on one of
the boards. Don’t worry, by this point we know where to look and we’ve got your back. If it turns out to
be something that you can’t handle we’ll fix it for you. A working tuner is included in the purchase
price.

3
2. SPECIFICATIONS
ITEM SPECIFICATION
requency Range 160, 80, 60, 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 0-6.4 uH in 128 steps
Capacitance Range 0-1300 p in 128 steps
Memory 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)
Size Does not affect the overall HR50 size.
Weight Adds about 1 lb (0.45 kg) to the HR50 amplifier

4
3. ASSEMBLY OVERVIEW
Assembling the Hardrock-50 ATU kit should be an enjoyable and rewarding experience. If at any time
you feel frustrated or are having difficulty, take a break, ask questions on the forum or email, and
remember that if you are having a problem with something there’s a good chance that someone else has
had the same issue. We have a “no questions asked” replacement part policy, so if you lose a part or
need an extra length of wire or find something missing an email is all it will take to get you a
replacement.
The assembly is organized into the following subassemblies:
•Inventory
•Inductors and Transformers
•PCB Assembly
•Amplifier prep (only needed on older amps)
•Integration and final assembly
•Firmware update
The inventory information is the first thing so you can make sure that nothing is missing. There are a
few required tools:
•Soldering iron – A small temperature controlled unit is the best.
•Solder – Rosin core, fairly thin
•Screwdrivers –All of the screws in the kit are Philips
•Tweezers – For holding small parts and reaching tight areas
•Wire Stripper – Some users have had trouble stripping the #30 wire. The best tool I have found
for this is the Ideal Industries 45-125 T7 Single Wire T-Stripper, 22-30 AWG. It costs less than
$15. Buying the toroid kit from the Toroid Guy eliminates the need to strip #30 wire.
•Long-nose pliers – For general mechanical assembly and crimping pins
•Toothpick – For unbraiding coax
In a production environment, an assembly station would also include an anti-static mat and all work
would be performed while wearing an anti-static wrist strap. If you are equipped with these, I encourage
you to use them. If you don’t have these items, use caution when handling the ICs on the ATU PCB and
touch a grounded surface before picking up the device.

4. ATU INVENTORY
PART ID
PART NUM
J1
1009
LA, LB, LC, LD, LE
1003
L , LG
1003
L1
1003
R _IN, R _OUT
1009
RLY1,RLY2,RLY3,RLY4,RLY5,
RLY6,
RLY7,RLY8,RLY9,RLY10,RLY
11,RLY12,
RLY13,RLY14,RLY15,RLY16,
RLY17
1006
T1
1003
SPACER
1002
SCREW
1000
MOUNTING NUTS
1001
TOROID WIRE
5
PART NUM
DESCRIPTION
PICTURE
1009
-
0004
10 PIN DUAL ROW
HEADER
1003
-
0005
T68-6 POWDERED IRON
CORE
1003
-
0004
T68-2 POWDERED IRON
CORE
1003
-0002 T50-2 POWERED IRON
CORE
1009
-
0001
3.5MM TERMINAL
BLOCK 2 POS
1006
-
0001
RELAY TELECOM DPDT
3A 12V
1003
-
0001
BN43-202 BINOCULAR
CORE
1002
-0005 #4-40 x ½" 3/16" MALE-
EMALE THREADED HEX
STANDAO s
1000
-
0007
#4
-
40 x ¼” WITH
INTEGRATED LOCK
WASHER
1001
-
0001
#4 MACHINE NUTS
WITH
INTEGRATED LOCK
WASHER
#20 ENAMELED WIRE
PICTURE
QUANT
ITY
1
5
2
1
2
17
1
2
2
2
90”

6
DIRECTIONAL COUPLER
#22 WHITE TE LON
WIRE
6”
15cm
DIRECTIONAL COUPLER WIRE
#30 KYNAR WIRE
3’
76cm
R _IN, R _OUT
RG
-
316
1’
30.5cm
1012
-
0001
3
-
PIN HEADER WITH
BARE WIRES
1

7
5. INDUCTORS AND TRANSFORMERS
This section describes the construction of the inductors and the transformer that will be installed on the
ATU PCB in the next section.
You can order prewound toroids inductors the Toroid Guy. An order form is available on the ATU
Resource Site:
https://sites.google.com/site/hr50atu/
Tips for Winding Toroidal Inductors:
1. The enameled on wire included with the kit is designed to be removed by heat. No scraping is
required. After the inductor is wound, tin the end with a soldering iron which will remove the
enamel and prepare the inductor for installation on the PCB. But there’s a trick, in order to get
the enamel hot enough burn off you must get molten solder in contact with bare copper which,
since we aren’t scraping, means the end of the wire. So get a nice ball of solder on the tip of the
iron and put the ball on the very tip of the wire, Then you will see the enamel cook right off.
Maybe when you are cutting the wire after the toroid is wound, cut the wire on a bias to expose
more bare wire.
2. There are two possible directions to wind a toroid. They are electrically identical but the PCB
layout favors right hand winding. When winding inductors always inset the initial turn of wire
and add turns to the right. This will insure that the inductors mount nicely on the PCB.
3. Tight, neat windings not only make your finished kit look professional but tighter coils have less
wire which leads to less resistance and higher Q so bend the wire around the toroid rather than
loop it.
□ L1 - 15 turns, 12" or 31cm of #20 enameled wire on a T50-2 Core (red), tinned. This is the smallest
torodial core, all the others are T68’s which are larger.

8
□ LA - 2 turns, 2" or 5cm of #20 enameled wire on a T68-6 Core (yellow), tinned.
NOTE: Wind this toroid by placing new turns to the left as shown. All other toroids are wound by
adding turns to the right.
□ LB - 4 turns, 5" or 12cm of #20 enameled wire on a T68-6 Core (yellow), tinned.