TX-500 - Wiring Coils.

Required Materials :


These are materials that I used for coils in TX500. If you don't have required magnet wires I suggest you buy them from Radio Shack. They have a great deal of three spool magnet wires (first picture above) for only $4.69 comparing to mouser.com that offers 1/2lb of a single choice for as much as $18. The package in Radio Shack includes 14 meters of 22AWG (.065mm) wire, 25 meters of 26AWG (0.4mm) wire and 65 meters of 30AWG (0.25mm) wire. Second picture shows a miniature ferrite beads that I found in my junk box. If you don't have any of these and can't find them you may also use many other types which I will try to post soon. Radio Shack also sells a package of 30 mixed chokes and coils for very low price. There are two small components that may replace the use of four small beads that you will need. In other words one such component looks and does exactly the same job as two ferrite beads connected together as on a picture below. If you can't get any ferrite beads you may replace L4, and L7 (4 beads) with a regular air coils. I will post more information about that soon.

The above pictures show all finished coils that I used in TX500. They are very easy to make and there are always many alternatives in you can't find any needed part.

L1 (oscillator's coil):


3.5 turns of 0.5mm / 24AWG magnet wire on 5mm diameter.

This is a high precision tunable coil. It is a pre-made coil that I took from a high quality FM radio from my junk box.
If you can't find anything similar then don't worry. Make a regular air coil similar to the one below (L2, L8) but only with 3.5 turns.
Just so you know, you may use any kind of wire thickness starting from 0.4mm to 1.5mm as long as the coil will be made the same way.
I even tried 0.25mm wire once and it worked fine but these wires are very fragile and you don't want to use such a thin wires in an oscillator - unless you put a resin on it to make it firm.

L2, L8:


4 turns of 0.65mm / 22AWG magnet wire on 5mm diameter.

1. Cut 9cm (3.5") of wire (1mm - 0.2m / 18 - 30AWG wire is fine as well).
2. Make 4 complete turns a shown on the pictures.



4 turns of 0.65mm / 22AWG magnet wire on 9mm diameter.

1. Cut 13cm (5") of magnet wire (1mm - 0.2m / 18 - 30AWG wire is fine as well).
2. Make 4 complete turns (as in L2, L8) on a 9mm diameter or a pencil.
3. Spread it to approximately 0.6mm

L4, L7:


4 turns on two small ferrite beads of 0.25mm / 30AWG magnet wire.

1. Cut 9cm (3.5") of magnet wire (you may also use a thinner wire with the same ferrite bead or thicker but then you will need a larger bead).
2. Make 4 turns. The first picture shows one complete turn, four turns will be complete when you will see four wires in the upper part.

These small beads are perfect to use in the transmitters up to 1W, above that I suggest you use a larger beads and a thicker wire.



4 turns on a ferrite bead.

1. Cut 10cm of 0.25mm / 30AWG magnet wire.
2. Make 4 turns on one small ferrite bead as shown on the pictures.

L6 (choke):


20 turns of 0.65mm / 22AWG wire on a ferrite ring.

If you don't have this type of ring try looking in an old computer power supply. (They may come in a different colors but they certainly will do the same job).

Accurate LC Meter Capacitance Inductance Meter with 16F628 and LCD
Volt Ampere Meter with 16F876 Microcontroller and LCD display
Accurate LC Meter

Build your own Accurate LC Meter (Capacitance Inductance Meter) and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils and inductors. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging as well as reset switch and produces very accurate and stable readings.
PIC Volt Ampere Meter

Volt Ampere Meter measures voltage of 0-70V or 0-500V with 100mV resolution and current consumption 0-10A or more with 10mA resolution. The meter is a perfect addition to any power supply, battery chargers and other electronic projects where voltage and current must be monitored. The meter uses PIC16F876A microcontroller with 16x2 backlighted LCD.

50MHz 60MHz Frequency Meter / Counter with 16F628 & LCD
1Hz - 2MHz XR2206 Function Generator
60MHz Frequency Meter / Counter

Frequency Meter / Counter measures frequency from 10Hz to 60MHz with 10Hz resolution. It is a very useful bench test equipment for testing and finding out the frequency of various devices with unknown frequency such as oscillators, radio receivers, transmitters, function generators, crystals, etc.
1Hz - 2MHz XR2206 Function Generator

1Hz - 2MHz XR2206 Function Generator produces high quality sine, square and triangle waveforms of high-stability and accuracy. The output waveforms can be both amplitude and frequency modulated. Output of 1Hz - 2MHz XR2206 Function Generator can be connected directly to 60MHz Counter for setting precise frequency output.

BA1404 HI-FI Stereo FM Transmitter
USB IO Board PIC18F2455 / PIC18F2550
BA1404 HI-FI Stereo FM Transmitter

Be "On Air" with your own radio station! BA1404 HI-FI Stereo FM Transmitter broadcasts high quality stereo signal in 88MHz - 108MHz FM band. It can be connected to any type of stereo audio source such as iPod, Computer, Laptop, CD Player, Walkman, Television, Satellite Receiver, Tape Deck or other stereo system to transmit stereo sound with excellent clarity throughout your home, office, yard or camp ground.
USB IO Board

USB IO Board is a tiny spectacular little development board / parallel port replacement featuring PIC18F2455/PIC18F2550 microcontroller. USB IO Board is compatible with Windows / Mac OSX / Linux computers. When attached to Windows IO board will show up as RS232 COM port. You can control 16 individual microcontroller I/O pins by sending simple serial commands. USB IO Board is self-powered by USB port and can provide up to 500mA for electronic projects. USB IO Board is breadboard compatible.

ESR Meter / Transistor Tester Kit
Audiophile Headphone Amplifier Kit
ESR Meter / Capacitance / Inductance / Transistor Tester Kit

ESR Meter kit is an amazing multimeter that measures ESR values, capacitance (100pF - 20,000uF), inductance, resistance (0.1 Ohm - 20 MOhm), tests many different types of transistors such as NPN, PNP, FETs, MOSFETs, Thyristors, SCRs, Triacs and many types of diodes. It also analyzes transistor's characteristics such as voltage and gain. It is an irreplaceable tool for troubleshooting and repairing electronic equipment by determining performance and health of electrolytic capacitors. Unlike other ESR Meters that only measure ESR value this one measures capacitor's ESR value as well as its capacitance all at the same time.
Audiophile Headphone Amplifier Kit

Audiophile headphone amplifier kit includes high quality audio grade components such as Burr Brown OPA2134 opamp, ALPS volume control potentiometer, Ti TLE2426 rail splitter, Ultra-Low ESR 220uF/25V Panasonic FM filtering capacitors, High quality WIMA input and decoupling capacitors and Vishay Dale resistors. 8-DIP machined IC socket allows to swap OPA2134 with many other dual opamp chips such as OPA2132, OPA2227, OPA2228, dual OPA132, OPA627, etc. Headphone amplifier is small enough to fit in Altoids tin box, and thanks to low power consumption may be supplied from a single 9V battery.

Arduino Prototype Kit
RF Remote Control 433MHz Four Channel
Arduino Prototype Kit

Arduino Prototype is a spectacular development board fully compatible with Arduino Pro. It's breadboard compatible so it can be plugged into a breadboard for quick prototyping, and it has VCC & GND power pins available on both sides of PCB. It's small, power efficient, yet customizable through onboard 2 x 7 perfboard that can be used for connecting various sensors and connectors. Arduino Prototype uses all standard through-hole components for easy construction, two of which are hidden underneath IC socket. Board features 28-PIN DIP IC socket, user replaceable ATmega328 microcontroller flashed with Arduino bootloader, 16MHz crystal resonator and a reset switch. It has 14 digital input/output pins (0-13) of which 6 can be used as PWM outputs and 6 analog inputs (A0-A5). Arduino sketches are uploaded through any USB-Serial adapter connected to 6-PIN ICSP female header. Board is supplied by 2-5V voltage and may be powered by a battery such as Lithium Ion cell, two AA cells, external power supply or USB power adapter.
200m 4-Channel 433MHz Wireless RF Remote Control

Having the ability to control various appliances inside or outside of your house wirelessly is a huge convenience, and can make your life much easier and fun. RF remote control provides long range of up to 200m / 650ft and can find many uses for controlling different devices, and it works even through the walls. You can control lights, fans, AC system, computer, printer, amplifier, robots, garage door, security systems, motor-driven curtains, motorized window blinds, door locks, sprinklers, motorized projection screens and anything else you can think of.

Electronics-DIY.com © 2002-2023. All Rights Reserved.