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

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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

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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.

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□ LC - 6 turns, 7" or 17cm of #20 enameled wire on a T68-6 Core (yellow), tinned.
□ LD - 9 turns, 10" or 25cm of #20 enameled wire on a T68-6 Core (yellow), tinned.

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□ LE - 13 turns, 12" or 31cm of #20 enameled wire on a T68-6 Core (yellow), tinned.
□ LF - 17 turns, 15" or 38cm of #20 enameled wire on a T68-2 Core (red), tinned.

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□ LG - 24 turns, 21" or 53cm of #20 enameled wire on a T68-2 Core (red), tinned.
□ T1 – There are a total of 4 windings on T1’s BN43-202 core. At this time we will be installing the
two 10 turn windings. The 2 single turn windings will be added when the core is soldered to the ATU
PCB in the next section.
Wind 2 windings each using 18" or 48cm of #30 Kynar wire, 10 turns, one winding through each hole in
a BN43-202 core, like this:
You should be able to count 10 white wires in each hole in the core. Stripping the #30 Kynar wire can be
challenging. A 22-30 T-Stripper works very well and costs under $20 on Amazon.com. It’s also possible
to strip it with diagonal cutters but practice a few times before you wind T1. If you need more #30 just
let us know and we’ll send it out.

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6. ATU PCB
This section covers the assembly of the ATU PCB. Required tools and supplies are; soldering iron,
diagonal cutters, tweezers and long-nose pliers. Carefully inspect the ATU PCB looking for poor
soldering on the SMT components look for unsoldered ferrite beads; they seem to be prone to re-flow
issues. The photos show pre-production boards that have green soldermask. Production boards will be
blue
Top Side:
Bottom Side:

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□ Step 1: Solder the two 3.5mm terminal blocks one at position RF_IN and the other at RF_OUT on
the top side. The openings in the terminals for inserting wires should face the silk screen markings for
RF and GND.
□ Step 2: Cut 2 each, 1.5” (3.8 cm) pieces of white #22 Teflon wire, Strip the ends so that the
insulation remaining is 7/8” (2.2 cm) long, the length of the bare wires is not important just so it’s long
enough to go through the PCB. Tin the ends:
□ Step 3: Solder the 2 prepared #22 wires in to the holes in the T1 footprint as shown. Slide the BN43-
202 core with the #30 windings over the protruding #22 wires. Make sure that the #30 wires go into the
corresponding holes in the PCB. No wires should cross each other.
□ Step 4: Bend the core over, parallel to the PCB, insert the remaining #22 and #30 wires in their
corresponding holes, and solder all unsoldered connections. The photos show T1 being installed on a
green prototype PCB which is Rev B, installation is the same on later Revs.

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□ Step 5: Insert 10 pin dual row header into position J1 on the top side of the PCB. Orientation of the
header is not important. Solder all of the pins. It’s easy to melt the plastic base of the header which
causes the pins to become misaligned. Don’t touch the soldering iron to the pin, instead touch the iron
to the pad of the PCB only. Then apply solder, filling the hole in the PCB as quickly as possible.
□ Step 6: Relay can only be inserted in the PCB one way. Install relays RLY1-RLY17 at the locations
indicated on the silk screen. The easiest way to do this is place the relays as indicated on the top side of
the PCB then place a flat object (maybe a hard cover book or a small piece of wood) on top of the
relays. The flat object must be big enough to cover all of the relays. Then, holding the PCB, relays and
flat object like a sandwich, flip the whole thing over. Then solder one pin on each relay, pressing down
on the PCB in the area of the relay it ensure that the relay is flush with the PCB. You can then pick up
the PCB with the relays attached by a single pin each. Inspect each relay for position (should be flush
with the PCB), adjust if necessary. Then turn the PCB over and solder the other 7 pins on each relay.
□ Step 7: Insert L1, LA, LB, LC, LD, LE, LF and LG at their indicated positions on the top side of the
PCB. Pull each of the leads through the PCB from the back side using pliers to insure that the toroids are
secure against the PCB. Remove additional enamel if necessary and solder all leads and trim excess.
□ Step 8: Cut the leads of the 3 pin connector with wires to 6” or 15 cm in length. Remove 0.5” or 1.25
cm of the insulation from each of the 3 wires, twist the strands tightly and tin with solder. Insert the
black wire into the GND pin of J3, the yellow wire into the 13.8V pin of J3 and the red wire in the 5V
TX pin of J3. Solder all 3 wires and trim excess.

15
Note for Rev C and Rev E amplifier boards (S/N less than 1200) you MUST reverse the red and black
wires in the 3 pin connector. Use a small screw driver to press on the locking tab and slide the wire and
pin from the housing
□ Step 9: Cut a 6" (15.2 cm) piece of RG-316. Remove 1/2" (1.3cm) of the outer jacket from each end
of the coax, unbraid the shield using a toothpick or similar and twist and tin the shield wires. Remove
the dielectric from the center conductor, twist and tin the center conductor wires. The RG-316 cable is
impervious to heat so tin the braid all the way around the cable to prevent fraying. Insert one end of the
jumper into the RF_IN terminal block with the center conductor connected to the RF terminal and the
shield connected to the GND terminal. Leave the other end free.
If your amp does not already have holes for the ATU in the bottom cover you can get the drill template
from https://sites.google.com/site/hr50atu/home/files and print it out. Measure the 3” or 100mm

16
reference lines to verify that your printer is scaling the drawing correctly, if it doesn’t, you can adjust
the print scaling factor in the Adobe Reader print screen so the lines are printed the correct length. Cut
out the template. Before removing the bottom cover of your HR50, use a piece of tape to mark the
bottom cover where the front panel is attached. The bottom cover is not reversible so if you use the
template incorrectly, the ATU will not fit inside. Remove the bottom cover and set the template on the
inside of the bottom cover carefully observing the front and back markings. The template should fit
perfectly inside the grove in the bottom cover. Mark the locations of the two mounting holes using a
center punch or a nail and hammer. Drill the two 1/8” or 3mm holes at the marked locations and
remove any burrs or excess material.
□ Step 10: Attach the two male-female spacers to the PCB with a #4 hex nuts with integral lock
washer.
□ Step 11: Slide the ATU PCB into the appropriate groove in the HR50’s bottom cover, align the
stand-offs with the holes in the bottom cover and attach with the two remaining #4-40 x ¼ screws.
The RF_OUT terminal block should be close to the ‘long’ side of the case (the back) line this:

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7. RETROFIT (FOR HR50 AMPS BELOW S N 1400)
For amplifiers with serial numbers below 1400, you will need to make some changes to the amplifier to
accommodate the ATU please contact [e-mail] for further instructions. All amplifiers
shipped from January 2015 and beyond ate 100% compatible with the ATU and need no retrofit.

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8. INTEGRATION
This section covers the final integration steps needed to get the ATU in the Hardrock-50’s case and
working with the HR-50’s firmware. At this point, you should have the ATU board mounted to the
bottom cover and if necessary preformed all necessary retrofit to the amplifier PCB. If you haven’t done
so, use the instructions in the ‘Firmware Update’ section of this manual to update the HR-50 to the latest
version. Firmware versions earlier than 3.0 will not recognize the ATU. The ribbon cable must be in
place to update the HR-50 firmware.
□ Step 1: Cut a 6" (15.2 cm) length of RG-316. Remove 1/2" (1.3cm) of the outer jacket from and of
each end of the cable, unbraid the shield using a toothpick or similar and twist and tin the shield wires.
Remove the dielectric from the center conductor, twist and tin the center conductor wires. The RG-316
cable is impervious to heat so tin the braid all the way around the cable to prevent fraying.
□ Step 2: Attach one end of the jumper from Step 1 to the ‘OUT’ SO-239 connector. If there is a short
jumper going from the ‘OUT’ jack to ‘RF_OUT’ on the amp PCB remove and discard it before
installing the new jumper.
□ Step 3: Orient the two halves of the case as shown in the photo below. Connect the coax jumper
attached to RF_IN TB on the ATU board to the RF_OUT TB on the amp PCB, if the amp has the QSK
mezzanine board installed, the RF_OUT connection will be on the QSK board. Connect the coax jumper
attached to the ‘OUT’ SO-239 to the RF_OUT TB on the ATU board.