Inspire VLF-3 User manual

VLF-3 Assembly Instructions
1
INSPIRE VLF-3 Receiver Kit
Assembly Instructions
The following assembly instructions should be followed carefully. The INSPIRE VLF-3
receiver kit is NOT a simple electronic assembly. If you follow the instructions carefully you
should be successful in building a receiver that works. If you are not careful, you run the risk of
having a problem that is very difficult to locate and fix. Be careful, take your time, and GOOD
LUCK!
TOOLS NEEDED:
Philips head screwdriver
Small standard screwdriver
Wire cutters
Wire stripper
Soldering iron (15-25 watt, small tip)
Light duty resin core solder (60/40)
Sponge
Magnifying glass
Solder sucker or solder wick
KIT CONTENTS:
1. Black plastic enclosure
2. Face Plate
3. Printed Circuit Board (PCB)
4. Four bags of components:
Bag 1 resistors, inductors
Bag 2 capacitors
Bag 3 ICs, diodes, sockets
Bag 4 switches, jacks, knobs, antenna terminal, wires, misc. hardware

VLF-3 Assembly Instructions
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Printed Circuit Board (PCB):
Faceplate
Front Control Panel
Component Side / Battery Side
All electronic components are inserted
from this side and soldered on the other
side. The battery holder is inserted
from this side also.
Switch Side
The four DPDT slide switches, the two
10k pots and the two LEDs are inserted
from this side and soldered on the other
side.

VLF-3 Assembly Instructions
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R5
+
–

VLF-3 Assembly Instructions
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ASSEMBLY SEQUENCE
1. Solder components to PCB.
2. Assemble jacks subassembly, connect wires to antenna terminal.
3. Connect wires to PCB.
4. Final assembly of receiver.
5. Test receiver.
(Check off boxes as each step is completed.)
1. Solder components to PCB.
(NOTE: The transistor (Q1) and the field effect transistor (J-FET with ferrite bead) have been
preinstalled.)
1a. Sort and install resistors.
Remove the resistors from Bag 1. Leave the
inductors for later installation.
The colored bands on the resistors indicate the resistance
using a color code. This table indicates how to convert each
color to its numerical equivalent.
0 black
1 brown
2 red
3 orange
4 yellow
5 green
6 blue
7 violet
8 gray
9 white
gold: 5% tolerance.
To read a resistor code, first locate the gold band and
read the colors in order from the other end. (All resistors in
this kit have a gold band indicating 5% tolerance.) The first
two bands indicate digits in the resistance, the third band
(called the multiplier) indicates the number of zeroes to be
added to the digits to obtain the resistance.
(NOTE: 1000 = kilo = k ; 1,000,000 = mega = Meg)
Bag 1 Contents
Resistors:
R1 560 kΩ
R2 10 Ω
R3 2.2 MegΩ
R4 22 MegΩ
R5 680 Ω
R6, R12 220 Ω
(R7, R26 10k pots in Bag #4)
R8 43 kΩ
R9, R17 10 kΩ
R10, R13 2.2 kΩ
R11 470 Ω
R14 100 kΩ
R15, R16, R20 20 kΩ
R18 15 kΩ
R19, R25, R27 100 Ω
R21, R22, R23, R24 1 kΩ
R28 270 kΩ
Inductors
L1 3.9 mH
L2 150 mH
Band 2
Band 3
Band 4
(gold)
Band 1

VLF-3 Assembly Instructions
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What is the resistance for each of the following?
Example 1
Example 2
Example 3
Example 4
Band 1
Band 2
Band 3
brown
black
brown
yellow
violet
orange
red
black
green
orange
orange
orange
Band 1
Band 2
Band 3
1
0
1
4
7
3
2
0
5
3
3
3
Resistance
100
100 Ω
47000
47 kΩ
2000000
2 MegΩ
33000
33 kΩ
Use the resistor code to identify and sort all of the resistors. One good way to keep them
sorted is to tape one end to a piece of paper and write the resistance and component number (R1,
R2, etc.). Once you have identified and sorted all of the resistors, you are ready to solder them to
the PCB.
To prepare a resistor for insertion into the board, bend the two leads so that they form a
right angle to the resistor body.
Resistor locations on the component side of the PCB are indicated with the “R” number from the
parts list between the two holes for insertion of the leads.
Part of the PCB showing location of R1, R3, R4 and R6.
To install, place the leads of the resistor through the appropriate holes and press the
resistor down against the component side of the PCB. (There is no required orientation for
resistors. Either lead may be inserted in either hole.) Turn the board over while holding the
resistor in position and bend the leads slightly outward to hold the resistor in place and solder the
leads to the circuit side. (NOTE: There will be an empty resistor symbol on the PCB between
R15 and R20. No part will be installed in this location.)

VLF-3 Assembly Instructions
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STEPS FOR SOLDERING RESISTORS, CAPACITORS AND WIRES:
IMPORTANT:
DO NOT leave a soldering iron plugged in for
a long time without using it.
NEVER leave a hot soldering iron unattended.
.
PCB
TRIM
PCB
Finished solder joint
Soldering iron
PCB
Touch solder to the side
of the lead away from
the soldering iron.
PCB
lead
contact
PCB
Press soldering iron
firmly down against the
contact and to the side
against the lead.
1. Clean the tip of the iron by wiping it on
the wet sponge.
2. Place a small amount of solder on the
tip.
3. Press the tip down against the circuit
contact and against the resistor lead and
hold for 5 seconds.
4. After the lead and the contact have
heated for 5 seconds, apply the solder to the
lead and contact (NOT directly to the iron)
until the solder melts and flows around the
lead and into the contact.
5. Apply enough solder to allow it to run
down along the lead. Do not apply so
much solder that it runs across the PCB
surface.
6. After enough solder has been applied (1-
2 seconds), remove the solder wire but hold
the iron in place for another 2-3 seconds.
7. Remove the iron, allow the joint to cool
and inspect the joint.
8. Trim the excess lead wire just above the
solder joint.
Repeat this process for the remaining
resistors.
Leave soldering iron in
place for 1-2 more
seconds.

VLF-3 Assembly Instructions
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IMPORTANT Note for New Soldering Irons:
A new soldering iron must be “tinned” in order to work well. Follow these steps:
1. Plug in the iron.
2. When it first heats up, apply solder liberally to the tip.
3. Wipe off the excess solder and you are ready to go!
1b. Install the IC sockets.
Remove the IC sockets and IC1 (LM386) and IC2 (LM358) from Bag #3. When
installing IC sockets and ICs, alignment is very important. One end of the IC symbol on the
PCB has a half-hole at one end of the symbol. One end of the socket has a half-hole. The IC
itself has a circular dot near one end.
Install the sockets so that the half-hole end coincides with the half-hole on the PCB.
Press the sockets firmly against the component side of the PCB. Solder the 8 pins on the other
side of the PCB taking care not to create any solder “bridges” between the pins.
Install the IC so that the end with the dot is at the end of the socket with the half-hole.
Carefully fit the 8 pins in the socket holes and press the IC firmly into the socket.
IC
PCB
HALF HOLE
DOT
Socket
PCB

VLF-3 Assembly Instructions
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1c. Solder capacitors to the PCB.
Capacitor Identification Guide
The small-value ceramic capacitors may be installed
in either orientation, but the larger-value cylindrical
capacitors (C4, C8, C10, C14, C16, C18, C19) must be
installed with the proper polarity.
The polarity is indicated on the PCB by a “+” sign
near one end of the capacitor location.
The polarity is indicated on the body of the
capacitor with a stripe with a minus (-) sign located on the
negative side of the capacitor. Also, the shorter lead is the
negative lead.
To install a capacitor, insert the leads in the
appropriate holes and press the capacitor down near the
PCB. Solder using the same technique as used for resistors.
The polarity is not marked on capacitor C 10.
The proper polarity is indicated here:
NOTE: There may be some variation in capacitor markings due to using different
suppliers.
Bag #2 Contents
Capacitors:
C1, C3 24 pF
C2, C6, C7 .01 µF
C4, C10, C18 10 µF
C5, C9, C13, C15,
C17, C21, C22
C8 1 µF
C11, C12 .001 µF
C14, C16 330 µF
C19 100 µF
C20 .15 µF
}
.1 µF
C11, C12
.001 µF
“102”
C1, C3
24 pF
“240J0”
C2, C6, C7
.01 µF
“103”
C4, C10, C18
10 µF
C8
1 µF
C5
C9
C13
C15
C17
C21
C22
.1 µF
“104”
C14, C16
330 µF
C19
100 µF
C20
.15 µF
“154”
C 10
+

VLF-3 Assembly Instructions
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!1d. Install the inductors (L1 and L2)
The inductors are the two remaining parts in Bag #1. Inductor L1 is marked “LH 239”..
Inductor L2 is marked “LJ 415”. From the component side, press the inductor firmly down
against the PCB and solder the other side. There is no required polarity for the inductors.
!1e. Install the diodes from Bag #3.
Polarity is very important in the
installation of diodes.
D1 and D2 are black cylinders with a
silver stripe near one end.
On the PCB, the D1 and D2 locations are shown
as a rectangle with a stripe near one end.
Align the striped end of the diode with
the striped end of the PCB symbol. Press the
diode firmly against the component side of the
PCB and solder the other side.
Z1 and Z2 are small components with a black stripe near one end. The symbol on the
PCB is the same as for D1 and D2. As with D1 and D2, align the black stripe end with the
striped end on the PCB. Press the diodes firmly against the PCB and solder the other side.
Return the LEDs to Bag #3. They will be installed later.
D1
1N
4004
Remaining Bag #3 Contents
D1, D2
Z1, Z2
LED1, LED2

VLF-3 Assembly Instructions
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1f. Install the battery holder.
From Bag #4, take the following parts:
1. Battery holder
2 PCB standoff post
2 4-40 3/8 “ screw
4 4-40 1/4” screw
2 4-40 nuts
2 nylon washers
2 #4 washers
The following diagram shows the assembly of the battery holder to the PCB:
.
1. Place the battery holder
leads through the PCB from
the component side and press
the holder firmly against the
PCB.
2. Insert 1/4” screws through
the holes nearest the leads,
through the PCB and tighten
the nuts on the switch side.
3. Insert 3/8” screws through
the other two holes, through
the PCB, through the nylon
washers and tighten the
standoffs on the switch side.
4. Solder the battery leads on
either (or both) side of the
PCB.
5. Temporarily insert 1/4”
screws through the #4 washers
in the other ends of the
standoffs. These will be used
later to attach to the face plate.