Elecraft T1 User Manual
ELECRAFT T1 AUTOMATIC ANTENNA TUNER
Assembly Manual
Revision D1, October 18, 2011. Copyright © 2011, Elecraft; All Rights Reserved
Introduction
This manual covers assembly of the Elecraft T1 automatic antenna tuner. Operating instructions,
troubleshooting procedures, schematic diagram and customer service information can be found in your T1
Owner’s Manual.
Tools Required
You will need the following tools to build this kit:
Fine-tip temperature-controlled ESD-safe soldering station with 700 to 800F tip (370-430C).
Recommend a spade tip no greater than 0.05” (1.3 mm) wide.
High wattage (approx. 100 watt ) solde r ing gun to solder the BNC connectors. Use this iron only
where directed in the procedure. Use the temperature-controlled station for all other soldering.
IC-grade, small-diameter (.031”) solder (Kester #44 or equivalent). Small diameter solder is
important to avoid filling adjacent solder pads and creating solder bridg e s.
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DO NOT use acid-core solder, water-soluble flux solder, additional flux or solvents
of any kind. Use of any of these will void your warranty.
Small, #2 Phillips screwdriver.
Needle-nose pliers.
Small wrench or driver for 6-32 nut.
Small-point diagonal cutters. Fl ush -cutting type required (Xcelite MS54-5J or equivalent).
Digital Multimeter (DMM) with voltage, resistance and diode-checking functions. A DMM with
capacitance measurement capability is desirable, but not required.
Magnifying visor or magnifying glass with a hands-free stand.
Desoldering tools and supplies are invaluable. Narrow solder wick or a good vacuum desoldering
tool such as the Soldapullt® model DS017LS are recommended.
Small, #2 (1.4 mm wide) blade screwdriver may be required.
Elecraft • www.elecraft.com • 831-763-4211
We strongly recommend that you use a conductive wrist strap and anti-static mat while handling the MCU
or the PC boards with the MCU installed. Wrist straps and mats are available at very low cost from Jameco,
Mouser, and other electronics suppliers.
Refer to www.elecraft.com for tool sources and solder recommendations.
Unpacking and Inventory
Preventing Electro-Static Discharge Damage
The Master Control Unit (MCU) used in the T1 automatic antenna tuner is sensitive to Electro-Static
Discharge (ESD) damage. ESD damage may not make the tuner fail completely. Sometimes the unit may
continue to operate somewhat, creating a very difficult-to-find problem. We strongly recommend that you
take the following precautions whenever handling the MCU or the PC boards when the MCU is installed.
The precautions are listed in their order of importa nce:
1. Leave the MCU in its anti-static packaging until you install it.
2. Wear a conductive wrist strap with a 1-megohm series resistor when handling the MCU or the
boards with the MCU installed. If you do not have a wrist strap, frequently touch an unpainted
ground while working. You can collect a destructive charge on your body just sitting at the work
bench. Do not attach a ground directly to yourself as this poses a serious shock hazard.
3. Use an ESD-safe soldering iron with a grounded tip.
4. Use a grounded anti-static mat on your work bench.
Identifying Capacitors
Capacitors are identified by their value and the spacing of their leads.
Small-value fixed capacitors are usually marked wit h o ne, two, or t hree di gi t s and n o dec imal point. If one
or two digits are used, that is the value in picofarads (pF). If there are three digits, the third digit is a
multiplier. For example, a capacitor marked "151" would be 150 pF (15 with a multiplier of 10
"330" would be 33 pF, and "102" would be 1000 pF (or .001 µF). Exceptions are described specifically in
the text and parts list.
Fixed capacitors with values of 1000 pF or higher often use a decimal point in the value, such as .001, .047,
or 2.2. This is the value in microfarads (µF) (1 µF is equal to 1,000,000 pF).
Most of the capacitors in this kit have a lead spacing of 0.2”. When a capacitor with a lead spacing of 0.1”
is called for, it is stated in the description, e.g. Capacitor C20, .01 µF, LS 0.1” (103).
Identifying Resistors
Resistors are identified by their power dissipation rating and their resistance value. The power rating is
indicated by their physical size. There are both 1/4 watt and 1/8 watt resistors in your T1 tuner kit. The 1/8
watt resistors are about one-half the size of the 1/4 watt resistors.
2
1
). Similarly,
The color bands that indicate the value of resistors are shown in the text to help you identify the correct
part. However, it’s helpful to familiarize yourself with the color code (see Figure 1). For example, a resistor
with the color bands of brown, red, yellow, gold would be a 120K ohm, 5% resistor. This resistor will be
identified in the text as 120K ohm (brn-red-yel).
If you are in doubt about a resistor’s value, use a DMM. Do not be concerned with minor deviations from
the expected value. Typical errors on most DMMs and the tolerances of the resistors normally produce
readings that are slightly different from the values indicated by the color bands.
FIRST DIGIT
SECOND DIGIT
COLOR DIGIT
Black
Brown
Red
Orange
Yellow
Green
0
1
2
3
4
5
MULTIPLIER
MULTIPLIER
X 1
X 10
X 100
X 10K
X 10K
X 100K
TOLERANCE:
GOLD = 5%
SILVER = 10%
COLOR DIGIT
Blue
Violet
Gray
White
Silver
Gold
6
7
8
9
-
-
MULTIPLIER
X 1M
-
-
X 0.01
X 0.1
Figure 1. Resistor Color Code.
Soldering and Desoldering
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Use adequate ventilation when soldering; avoid inhaling smoke or fumes. Always wash your
hands after handling solder, as lead residue is highly toxic.
When applying solder, use the minimum amount required to surround the component lead and make good
contact with its printed-circuit pad. You don't need a "fillet" (build-up ) of solder. This will avoid unwanted
solder bridges and any need to clean the PC boards.
The solder must flow onto both the component lead and its PC board pad. To ensure that both will be
heated at the same time, the tip of the iron should contact both the component lead and the PC board pad
before solder is applied.
Solder joints should be clean and shiny. If a joint appears dull or has fine cracks, it is probably cold. Cold
solder joints should be cleaned and re-soldered. First, use solder wick (desoldering braid) to remove the old
solder. Then apply fresh solder. If you have many cold solder joints, it probably indicates that your
soldering iron temperature is too low, or that the tip or solder itself is defective.
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Elecraft kits use high-quality double-sided PC boards. Removing components can be difficult, since you
must get all of the solder back out of the hole before a lead can be removed. To do this, you'll need solder
wick (desoldering braid) and/or a vacuum desoldering tool. It also takes some practice. A number of
suggestions are provided below.
The best strategy for avoiding de-soldering is to place all components properly the first time. Double-check
values and orientations, and avoid damaging parts via ESD.
When removing components:
Don't pull a lead or pin out of a hole unless the solder has been removed or you are applying heat.
Otherwise you can literally pull the plating out of the plated-through hole.
Limit soldering iron contact to a few seconds at a time.
Use small-size solder-wick, about 0.1" or 2.5 mm wide. Use the wick on both the top and bottom pads
when possible. This helps get all of the solder out of the hole.
If you use a vacuum desoldering tool (solder sucker), use a large unit. Small solder suckers are not
very effective.
The safest way to remove ICs and other components with more than 3 leads is to clip all of the pins at
the body of the device first, then remove all of the pins individually. You may damage pads and traces
by trying to remove such components intact.
Invest in a PC board vice with a heavy base if possible. This makes parts removal easier because it
frees up both hands.
If in doubt about a particular repair, ask for advice from Elecraft or from someone else with PCB repair
experience.
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Parts List
We strongly recommend that you do a complete inventory before beginning assembly. The inventory helps
you correctly identify all the parts to avoid mistakes during assembly.
Ref. Photo Description Qty
T1 main PC board (larger board). This board has a number of
Misc.
Misc.
C8,9,11,12,
C15, 16, 17, 18,
CA, CB, CC,
CD, CE, CF,
CG, CH, CJ,
CK, CL, CM,
CN, CP, CR
C1, C5A
C10 Capacitor .001 µF, LS 0.1" (102) 1 E530074
C19 Capacitor 1.0 µF non-polarized, LS 0.1" (105) 1 E530174
C2 Capacitor, 20 pF, 500 V, NPO or C0G (20) 1 E530173
C3 Capacitor 39 pF, 500 V (39) 1 E530028
C4 Capacitor 82 pF, 500 V (82) 1 E530095
C5 Capacitor 150 pF, 500 V (151) 1 E530097
C6, C7, C7A Capacitor 330 pF, 500 V (331) 3 E530409
Pre-Installed
Surface-
Mount
Devices
Typical
Capacitor
Styles
surface-mount device (SMD) capacitors pre-installed on the
bottom.
T1 control PC board 1 E100236
Capacitor .01 µF 8 E530175
Capacitor .01 µF. On the PC board, these capacitors are
identified only by the second letter (e.g. A, B, C, D...)
Capacitor 10 pF, 500 V (10) 2 E530026
1 E850198
15 E530175
Part
Number
C20 Capacitor .01 µF, LS 0.1" (103) 1 E530019
R1,R2
R11 Resistor, 24K, 1/8 W, 5% (red-yel-org) 1 E500155
R3,R4,R13,
R14,R21
R5, R6, R7,
R10
R9 Resistor, 180 ohms, 1/8 W, 5% (brn-gry-brn) 1 E500157
U1
Resistors
1/8 -1/4 -1W
Resistor, 51 ohms, 1 W, 5% (grn-brn-blk or stamped 510J) 2 E500159
Resistor, 3.3K, 1/8 W, 5% (org-org-red) 5 E500156
Resistor, 120K, 1/8 W, 5% (brn-red-yel) 4 E500154
MCU,16F876A
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ESD Sensitive! Do not remove from
its packaging until instructed to do so.
1 E610020
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Ref. Photo Description Qty
Q1
Transistor 2N3906 1 E580000
Part
Number
U2 I.C. L78L06 or LM78L06 1 E600001
D1,D2, D4
D3
J1,J2
J3
J4, J5
P1, P2
Misc.
D6
D7 LED, yellow 1 E570020
D8 LED, red 1 E570019
Misc.
Z1
S1,S2
K1-K15
T1,T2
Diode 1N5711 3 E560004
Diode 1N5817 1 E560008
BNC female, PCB mount 2 E620075
Stereo jack, 3.5 mm, miniature 1 E620087
Conn., 0.1" spacing, 6 pin female, low-profile 2 E620096
Conn., 0.1" spacing, 6 pin male 2 E620095
Socket for U1, low-profile, 28 pins 1 E620074
LED, green 1 E570021
LED spacer 3 E570024
Ceramic resonator, 4.0 MHz 1 E660001
Switch, Tactile, SPST, 6 mm, actuator length 7 mm 2 E640022
Miniature DPDT relay 15 E640010
Toroid, FT37-43 (Gray) 3 E680003
L1-L5 Toroid, T37-6 (Yellow) 5 E680013
L6-L7 Toroid, T37-2 (Red) 2 E680006
Hardware
Hardware
Hardware
Hardware
Hardware
Hex nut, 6-32 1 E700040
Flat washer, #6 1 E700067
Knurled thumb-nut, brass, 6-32 1 E700094
Lock washer, #6 internal tooth, stainless 1 E700095
Solder lug, #6 1 E700096
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Ref. Photo Description Qty
Hardware
Hardware
Screw, 6-32 x 9/16” 1 E700100
Screw, #2, 9/16 inch self tapping 4 E700097
Part
Number
Misc.
Misc.
Misc. Enamel wire, #26, red 10 ft. E760002
Misc. Hookup wire, 28 AWG stranded, black 6 in. E760026
Misc. Hookup wire, 28 AWG stranded, red 6 in. E760027
Misc. Hookup wire, #24 solid, green insulation 6 in. E760008
Misc. T1 front panel label 1 E980104
Misc. T1 cover spacer, 1x1.75x0.125", foam, black, self-adhesive 1 E980107
Misc. T1 enclosure top and bottom cover 1 E100204
Misc. T1 enclosure end cover 1 E980106
Misc. T1 owner's manual 1 E740079
Misc. T1 assembly manual 1 E740080
9-volt battery clip, wide 1 E700099
9-volt battery clip, narrow 1 E700098
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Main PC Board Assembly
The main PC board is the larger of the two boards. The completed PC board is shown in Figure 2. Use this
figure for reference, but follow the step-by-step procedures as given. Some parts are very difficult to install
if done in the wrong sequence. Many parts are almost impossi bl e to remove without destroying the part or
damaging the PC board.
Top
Bottom
Figure 2. Completed Main PC Board.
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Main PC Board Assembly Procedure – Part I
OU
S
Install BNC connectors J1 and J2 as follows. When completed they must be aligned as shown
in Figure 3.
O
90
JACKS CENTERED
WITHIN
PRINTED
TLINE
JACK BARRELS
PARALLEL WITH
BOARD
USE HEAVY-DUTY
IRON TO SOLDER
MOUNTING NUBS
(SEE TEXT)
Figure 3. Installing J1 and J2.
__ Position BNC connector J1 on the board over the printed outline as shown with the mounting nubs and
center connector passing through the holes provided. Be certain the barrel is at a 90-degree angle with the
edge of the board and parallel to the board as shown in Figure 3.
__ While holding the connector in place, wet the tip of your iron with a drop of solder and use it to
temporarily tack-solder the connector center terminal.
__ Check to ensure the connector is still aligned as shown in Figure 3. If not, re-heat the tack soldered join t
and adjust the position. It will be very difficult to adjust the connector after you complete the next step.
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In the following step you will use a large iron to solder the two mounting nubs on the BNC
connector to the board. This is the only time you should use anything other than a temperature-
controlled, ESD-protected soldering station to assemble your T1 tuner.
__ Place the board the bottom side up on a surface that wi ll not be dam aged if body of the BNC connector
becomes warm. Apply the large iron and solder to the end of one amounting nub where it protrudes through
the circuit board. Remove the iron as soon as the solder flows onto the pad. Do not put the iron directly on
the solder pad. Do not be concerned if solder fills the pad marked G near J1.
__ Solder the second mounting nub using the same procedure.
__ Using your temperature-controlled iron, properly solder the center pin that you tack-soldered earlier.
__ Repeat the above procedure to install the second BNC connector, J2.
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