Vectronics VEC-1012K User Manual

VEC-1012K Owner’s Manual

INTRODUCTION

If you like prowling the airwaves to gather news first-hand, the VEC-1012K is the perfect kit for you! Tune in local fire, police, ambulance, public service, commercial business, and marine traffic as you search for real-life on-air drama. Before you know it, you'll master 2-way radio lingo, special operating procedures, and police 10-codes as you ferret out the "real story" behind the news! You'll also master hands-on electronic construction skills. Detailed stepby-step assembly instructions guide you through each stage, and clearlypresented alignment procedures ensure top performance without need for expensive test equipment. Your receiver is built around a Motorola IC designed especially for na rrow-band FM communicatio n radios, so i t's guaranteed to pull in weak signals--just like the best commercially-built scanners and two-way transceivers. Electronic tuning lets you scan the band quickly for activity without need for entering complex strings of microprocessor commands. And, once you've found the action, your radio's fully adjustable "tail-free" squelch eliminates annoying background noise between transmissions. The VEC-1012K uses minimal energy, and can run for many hours from its self-conta ined 9-volt flat-pack alkaline battery. Plug in a 8-ohm speaker or use headphones for loudand-clear reception. All circuitry is self-contained on a rugged 3" x 3.2" pc board.

TOOLS AND SUPPLIES

Construction Area: Kit construction requires a clean, smooth, and well-lighted area where you can easily organize and handle small parts without losing them. An inexpensive sheet of white poster board makes an excellent construction surface, while providing protection for the underlying table or desk. Welldiffused overhead lighting is a plus, and a supplemental high-intensity desk lamp will prove especially helpful for close-up work. Safety is an important consideration. Be sure to use a suitable high-temperature stand for your soldering iron, and keep the work area free of combustible clutter.

Universal Kit-building Tools: Although your particular kit may require additional items to complete, virtually all construction projects require a work area outfitted with the following tools and supplies:

! Soldering Iron (grounded-tip and temperature-controlled preferred) ! High-temperature Iron Holder with Cleaning Sponge ! Rosin-core Solder (thin wire-size preferred) ! Needle Nose Pliers or Surgical Hemostats ! Diagonal Cutters or "Nippy Cutters"

VEC-1012K Owner’s Manual

! Solder Sucker, Vacuum Pump, or Desoldering Braid ! Bright Desk Lamp ! Magnifying Glass

Special Tools for This Kit:

! 6-32 screw, at least 3/4" long, for winding coils. ! Insulated hex-head tuning wand. ! Small flat-blade screwdriver or tuning wand. ! Voltmeter, digital or analog. ! VHF "high-band" antenna to receive off-air signals.

BEFORE YOU START BUILDING

Experience shows there are four common mistakes builders commonly make. Avoid these, and your kit will probably work on the first try! Here's what they are:

1. Installing the Wrong Part: It always pays to double-check each step. A 1K

and a 10K resistor may look almost the same, but they may act very differently in an electronic circuit! Same for capacitors--a device marked 102 (or .001 uF) may have very different operating characteristics from on marked 103 (or .01uF).

2. Installing Parts Backwards: Always check the polarity of electrolytic

capacitors to make sure the positive (+) lead goes in the (+) hole on the circuit board. Transistors have a flat side or emitter tab to help you identify the correct mounting position. ICs have a notch or dot at one end indicating the correct direction of insertion. Diodes have a banded end indicating correct polarity. Always double-check--especially before applying power to the circuit!

3. Faulty Solder Connections: Inspect for cold-solder joints and solder

bridges. Cold solder joints happen when you don't fully heat the connection-or when metallic corrosion and oxide contaminate a component lead or pad. Solder bridges form when a trail of excess solder shorts pads or tracks together (see solder tips below).

4. Omitting or Misreading a Part: This is easier to do than you might think!

Always double-check to make sure you completed each step in an assembly sequence.

VEC-1012K Owner’s Manual

Soldering Tips: Cleanliness and good heat distribution are the two secrets of professional soldering. Before you install and solder each part, inspect leads or pins for oxidation. If the metal surface is dull, sand with fine emery paper until shiny. Also, clean the oxidation and excess solder from the soldering iron tip to ensure maximum heat transfer. Allow the tip of your iron to contact both the lead and pad for about one second (count "one-thousand-one") before feeding solder to the connection. Surfaces must become hot enough for solder to flow smoothly. Feed solder to the opposite side of the lead from your iron tip--solder will wick around the lead toward the tip, wetting all exposed surfaces. Apply solder sparingly, and do not touch solder directly to the hot iron tip to promote rapid melting.

Desoldering Tips: If you make a mistake and need to remove a part, follow these instructions carefully! First, grasp the component with a pair or hemostats or needle-nose pliers. Heat the pad beneath the lead you intend to extract, and pull gently. The lead should come out. Repeat for the other lead. Solder may fill in behind the lead as you extract it--especially if you are working on a double-sided b o ar d with plat e-thr o ugh hol es. Sho uld this ha pp e n, tr y heat ing the pad again and inserting a common pin into the hole. Solder won't stick to the pin's chromium plating. When the pad cools, remove the pin and insert the correct component. For ICs or multi-pin parts, use desoldering braid to remove excess solder before attempting to extract the part. Alternatively, a low-cost vacuum-bulb or spring-loaded solder sucker may be used. Parts damaged or severely overheated during extraction should be replaced rather than reinstalled.

Work Habits: Kit construction requires the ability to follow detailed instructions and, in many cases, to perform new and unfamiliar tasks. To avoid making needless mistakes, work for short periods when you're fresh and alert. Recreational construction project are more informative and more fun when you take your time. Enjoy!

Sorting and Reading Resistors: The electrical value of resistors is indicated by a color code (shown in the following chart). You don't have to memorize this code to work with resistors, but you do need to understand how it works:

Resistor Color Code

1st Digit 2nd Digit Multiplier

Tolerence

(gold or silver)

Black = 0 (tens) Brown = 1 (hundreds) Red = 2 (K) Orange = 3 (10K) Yellow = 4 (100K) Green = 5 (1Meg)

Blue = 6 Violet = 7 Gray = 8 White = 9 Silver = 10% Gold = 5%

When you look at a resistor, check its multiplier code first. Any resistor with a black multiplier band falls between 10 and 99 ohms in value. Brown designates

VEC-1012K Owner’s Manual

a value between 100 and 999 ohms. Red indicates a value from 1000 to 9999 ohms, which is also expressed as 1.0K to 9.9K. An orange multiplier band designates 10K to 99K, etc. To sort and inventory resistors, first separate them into groups by multiplier band (make a pile of 10s, 100s, Ks, 10Ks, etc.). Next, sort each group by specific value (1K, 2.2K, 4.7K, etc.). This procedure makes the inventory easier, and also makes locating specific parts more convenient later on during construction. Some builders find it especially helpful to arrange resistors in ascending order along a strip of double-sided tape.

Some VEC kits may contain molded chokes which appear, at first glance, similar to resistors in both shape and band marking. However, a closer look will enable you to differentiate between the two--chokes are generally larger in diameter and fatter at the ends than resistors. When doing your inventory, separate out any chokes and consult the parts list for specific color-code information.

Reading Capacitors: Unlike resistors, capacitors no longer use a color code for value identification. Instead, the value, or a 3-number code, is printed on the body.

Value Code

10 pF = 100 100 pF = 101 1000 pF = 102

.001 uF = 102*

.01 uF = 103 .1 uF = 104

Multilayer

(270 pF)

271

Ceramic Discs

(.001 uF) (.1 uF)

102

104

Electrolytic

1 uF

1uF

35V

As with resistors, it's helpful to sort capacitors by type, and then to arrange them in ascending order of value. Small-value capacitors are characterized in pF (or pico-Farads), while larger values are labeled in uF (or micro-Farads). The transition from pF to uF occurs at 1000 pF (or .001 uF)*. Today, most monolithic and disc-ceramic capacitors are marked with a three-number code. The first two digits indicate a numerical value, while the last digit indicates a multiplier (same as resistors).

Electrolytic capacitors are always marked in uF. Electrolytics are polarized devices and must be oriented correctly during installation. If you become confused by markings on the case, remember the uncut negative lead is slightly shorter than the positive lead.

Diodes: Diodes are also polarized devices that must be installed correctly. Always look for the banded or cathode end when installing, and follow instructions carefully.

Cathode

VEC-1012K Owner’s Manual

(shorter Lead)

Diode

LED

Transistors: If transistors are installed incorrectly, damage may result when

power is applied. Transistors in metal cases have a small tab near the emitter lead to identify correct positioning. Semiconductors housed in small plastic cases (TO-92) have an easily-identified flat side to identify mounting orientation. Many specialized diodes and low-current voltage regulators also use this type packaging. Larger plastic transistors and voltage regulators use a case backed with a prominent metal tab to dissipate heat (T-220). Here orientation is indicated by the positioning of the cooling tab.

Metal Can Device Plastic Device Tab-cooled Device

Emitter

Flat Side

Metal Tab

Integrated Circuits: Proper IC positioning is indicated by a dot or square marking located on one end of the device. A corresponding mark will be silkscreened on the PC board and printed on the kit's parts-placement diagram. To identify specific IC pin numbers for testing purposes, see the diagram below. Pin numbers always start at the keyed end of the case and progress counterclockwise around the device, as shown:

8 7 6 5

Installation

Key

PARTS LIST

1 2 3 4

Pin Numbers

Installation

Key

Your kit should contain all of the parts listed below. Please identify and inventory each item on the checklist before you start building. If any parts are missing or damaged, refer to the manual's warranty section for replacement instructions. If you can't positively identify an unfamiliar item on the basis of the information given, set it aside until all other items are checked off. You may then be able to identify it by process of elimination. Finally, your kit will go together more smoothly if parts are organized by type and arranged by value ahead of time. Use this inventory as an opportunity to sort and arrange parts so you can identify and find them quickly.

VEC-1012K Owner’s Manual

Resistors:

Qty Part Description Designation

1 22 ohm (red-red-black) R3

1 270 ohm (red-violet-brown) R4

1 470 ohm (yellow-violet-brown) R2

2 2.2K (red-red-red) R11,R14

2 4.7K (yellow-violet-red) R7,R17

2 10K (brown-black-orange) R5,R18

2 39K (orange-white-orange) R12,R15

1 47K (yellow-violet-orange) R8

4 100K (brown-black-yellow) R1,R9,R13,R19

2 10K potentiometer R6,R16

1 100K potentiometer R10

Capacitors:

Qty Part Description Designation

1 2.2 pF disc ceramic (2.2C) C3

8 .1 uF disc ceramic (104) C10,C11,C12,C21,C22,

C24,C26,C29

1 .05 uF disc ceramic (503) C27

1 6.8 pF disc ceramic (6.8J or 6.8C) C5

1 4.7 pF disc ceramic (4.7J or 4.7C) C1

5 .001 uF disc ceramic (102) C6,C13,C14,C25,C32

2 1 uF electrolytic C23,C28

2 10 uF electrolytic C30,C31

2 100 uF electrolytic C8,C9

2 15 pF multilayer (15 or 150) C17,C18

1 18 pF multilayer (18 or 180) C19

2 22 pF multilayer (27 or 270) C2,C4

Capacitors cont.

Qty Part Description Designation

1 56 pF multilayer (56 or 560) C20

1 100 pF multilayer (101) C7

2 470 pF multilayer (471) C15,C16

Semiconductors:

Qty Part Description Designation

1 5.1 volt zener diode, 1N751A D1

1 2SC2498 transistor Q1

1 MC13135 IC (24 pin) U1

VEC-1012K Owner’s Manual

1 MC34119 IC (8 pin) U2

Inductors/Filters/Crystals

Qty Part Description Designation

1 24" length of #24 coil wire For L1,L2,L3

1 .074 uH slug-tuned, shielded (red) L4

1 660 uH adjustable, shielded (black) L5

1 10.245 crystal Y1

1 10.7 MHz ceramic filter (SFE10.7J) FL1

1 455 KHz ceramic filter (55D or 55F) FL2

Switches/Jacks/Misc.

Qty Part Description Designation

1 DPDT push-button power switch SW1

1 RCA phono jack, pc-mounted J1

1 3.5mm stereo jack (mini-jack) J2

1 8-pin IC socket (for U2)

1 24-pin IC socket (for U1)

1 9-volt battery snap clip

1 plastic cable tie

1 PC board for VEC-1012K

1 VEC-1012K Owner's Manual

VEC-1012K Owner’s Manual

PARTS PLACEMENT DIAGRAM

STEP-BY-STEP CONSTRUCTION

In these instructions, when you see the term install, this means to locate, identify, and insert the part into its mounting holes on the PC board. T his includes prebending or straightening leads as needed so force is not required to seat the part. Once a component is mounted, bend each lead over to hold it in place. Use sharp side-cutters to clip off excess lead length before soldering. Make sure trimmed leads don't touch other pads and tracks, or a short circuit may result:

Good

The term solder means to solder the part's leads in place, and to inspect both (or all) solder connections for flaws or solder bridges. Nip off excess protruding leads with a sharp pair of side cutters. Generally, it's easier to install small closeto-the-board parts first, and then mount larger stand-up parts second. Delicate parts, such as air-wound, coils go on the PC board last.

Not Good

VEC-1012K Owner’s Manual

Your kit has 16 fixed-value resistors. We'll begin by mounting these now-starting with the smallest value and moving to the largest. Before mounting each one, carefully bend both leads close to the resistor body to form right-angles, as shown below:

.4"

! ! Find a 22 ohm resistor (red-red-black). Install at R3 and solder. ! ! Find a 270 ohm resistor (red-violet-brown). Install at R4 and solder. ! ! Find a 470 ohm resistor (yellow-violet-brown). Install at R2 and solder.

Locate two (2) 2.2K resistors (red-red-red).

! ! Install a 2.2K at R11 and solder. ! ! Install a 2.2K at R14 and solder.

Locate two (2) 4.7K resistors (yellow-violet-red).

! ! Install a 4.7K at R7 and solder. ! ! Install a 4.7K at R17 and solder.

Locate two (2) 10K resistors (brown-black-orange).

! ! Install a 10K at R5 and solder. ! ! Install a 10K at R18 and solder.

Locate two (2) 39K resistors (orange-white-orange).

! ! Install a 39K at R12 and solder. ! ! Install a 39K at R15 and solder. ! ! Find a 47K resistor (yellow-violet-orange). Install at R8 and solder.

Locate four (4) 100K resistors (brown-black-yellow).

! ! Install a 100K at R1 and solder. ! ! Install a 100K at R9 and solder. ! ! Install a 100K at R13 and solder. ! ! Install a 100K at R19 and solder.

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