SIGNAL TRACER

Circuit Diagram :-

Pulse-Generator & Signal-Tracer
Dual-purpose test-instrument
Very simple circuitry, 1.5V Battery-operated
Parts:R1__________________1M 1/4W Resistor
R2,R4_______________2K7 1/4W Resistors
R3________________150K 1/4W Resistor
C1__________________2n2 630V Ceramic or Polyester Capacitor (See Notes)
C2,C3_______________4n7 63V Ceramic or Polyester Capacitors
D1_______________1N4148 75V 150mA Diode
Q1________________BC547 45V 100mA NPN Transistor
Q2________________BC557 45V 100mA PNP Transistor
SW1________________SPST miniature Slider Switch (See Notes)
J1_________________Stereo switched 3mm. Jack socket (See Notes)
Probe______________Metal Probe 3 to 5 cm. long
Clip_______________Miniature Crocodile Clip
B1_________________1.5V Battery (AA or AAA cell etc.)
Device purpose:
This simple circuit generates narrow pulses at about 700-800Hz frequency. The pulses, containing harmonics up to the MHz region, can be injected into audio or radio-frequency stages of amplifiers, receivers and the like for testing purposes. A high-pitched tone can be heard from the speaker of the device under test when all is working properly. The clip must be connected to the ground of the device under test, touching with the probe the different stages of the circuit, starting from the last stage and going up towards the first. When the tone is no longer heard, the defective stage has been found.Connecting an earclip or headphone to J1, the circuit will automatically change into a two-stage amplifier and any audio signal coming from the device under test and picked-up by the probe will be heard through the headphones. The testing of a circuit should be made in the reverse manner, i.e. starting from the first stage and going down until the last stage. When nothing is heard, the defective stage has been found.
Circuit operation:
Q1 & Q2 form a complementary astable multivibrator, whose operating frequency is set mainly by R3, C2 & C3 values. Output pulses are taken at Q2 Collector and applied to the probe by means of decoupling capacitor C1. D1 provides a symmetrical shape for the output waveform.If an earclip or headphone jack is plugged into J1, the connection from Q2 Collector and C1 - C2 is broken by the switch incorporated into J1: in this case the circuit becomes a two-stage amplifier.
Notes:
If you intend to use the circuit to test valve operated devices C1 must be a 630V type. Working with low voltage supply transistor devices the voltage of C1 can be lowered to 63 or 100V.
If instead of a short probe, you intend to connect the circuit to the device under test by means of a piece of wire longer than a few centimeters, a small ceramic capacitor (470 to 1000pF) should be added in parallel to D1 to prevent unwanted RF oscillation.
Current drawing when in Pulse-Generator mode is about 60µA and 1.2mA when in Signal-Tracer mode operation. Therefore SW1 can be omitted, provided that the earclip or headphones are unplugged when the circuit is unused.
J1 is a stereo switched jack socket wired to obtain a series connection of the two earpieces forming a stereo headphone. In this manner the circuit is loaded with a higher impedance and sensitivity will be improved.Therefore, the higher the load impedance the more sensitive the Signal-Tracer. In any case, common 32 Ohm impedance mini-headphones suitable for walkman sets will work fine.
A crystal (high impedance) earpiece is a good solution, provided you substitute J1 with a mono switched jack socket.
The entire circuit can be easily fitted into a pen-like enclosure, with the probe protruding like a nib

AIRCRAFT RECEIVER

Description
R1, R3

Qty 2
47K 1/4W Resistor
R2
Qty 1
10K 1/4W Resistor
R4 Qty 1 4.7K 1/4W Resistor
R5 Qty 1 5K Linear Taper Pot
R6 Qty 1 2.2K 1/4W Resistor
C1, C2, C3, C6 Qty 4 0.001uF Ceramic Disc Capacitor
C4 Qty 1 2.2pF Ceramic Disc Capacitor
C5 Qty 1 1pF Ceramic Disc Capacitor
C7 Qty 1 15uF 15V Electrolytic Capacitor
C8 Qty 1 18pF Variable Capacitor
D1 Qty 1 1N82 Diode
Q1 Qty 1 2N918 NPN Transistor
L1 Qty 1
L2 Qty 1 1.8uH Inductor
ANT1

Approx. 18 Inch Wire Antenna
MISC
PC Board, Wire, Knob For C8

For many who live in the vicinity of the airport and would like to hear the qso between the control tower and the pilots this project will give them great pleasure.

THE ART OF EFFECTIVE ORAL COMMUNICATION

A for Audibility : The successful speaker strives to be heard by persons. This means that the speaker must project his/her voice. It must come from within and not from the throat.
B for Brevity and Begin Well An effective speech must be long enough to cover the subject, yet short enough to be interesting. One of the wisest pieces of advice given to speech – makers is. “ If you want to be seen, stand up, if you want to be heard, speak up, if you want to be appreciated, then shut up.” Arrest the attention of your audience from the start. You can use a joke or an anecdote, a startling statement
C for Clarity Sound all your words, especially the hard consonants like t,g, & d. Clarity requires that you articulate and pronounce every word clearly.
D for Diction : This implies the way you speak, you accent and pronunciation. Listening to news readers on BBC, CNN etc acquaint you with models of good speech.
E for Eye Contact Look at your audience when you speak. They must feel that you are talking to them., look into their eyes, not beyond, under or above them.
F the Friendly Formula : Look feel and sound friendly to your audience. This is communicated through your smile, your tone of voice, your facial expression and your positive outlook.
G : for Gestures They add meaning to what you say. They precede what we wish to say by a split second
There are 4 basic gestures – Acceptance, Rejection, Demonstrative and Determination indicated by palms facing upwards, palms facing downwards, pointing out and the clenched fist.
H for Hands Use them well. Do not stand with your hands in your pockets, behind your back or joined in front. Instead, let them hang loosely by your side and you caan use your hands to make an occasional, spontaneous gesture.
I for Interest .Interest your audience from the start and retain that interest. Use stories, jokes, quotations
J for Jokes : These enliven your speech. Weave them into your speech and see that they suit the context. For example listen to the Joker on the net.
K: for Kwality Kwality counts. It is not how long you speak, but what you say, that matters.
L: for Learn your Speech well: Memorize it well if necessary.
M : for Microphone It can be a blessing or a bane, depending on how you use it. There should be 6” or 4” finger distance between your mouth and the microphone and should be parallel to each other.
N: for Nervousness Notes help a speaker to feel more confident. Notes should be written on the back of old cards, written in dark ink
O : for Open your mouth wide and pronounce your words clearly.
P : for Pace The speed at which you speak. Avoid a pace that is too fast to be taxing to the hearers or too slow to be monotonous and uninteresting. Be brisk in your speech.
Q: for Quotations : Use them to advantage. Only they should be relevant and suitable, used at the right time and said in the right way.
R: for Relax A speaker needs to do so. Take a deep breath in and begin. Feel & be relaxed.
S: for Stance Avoid an unusual stance
T for Thank You The nicest way to end a speck. Politeness pays.
U: U have to decide whether to speak or not to speak. The choice is yours. The more you speak, the better for you.
V: for Vocabulary The power of words is tremendous. Use adjectives and adverbs to embellish your speech.
W: for Wait till you have the attention of your audience. Do not start right away. Pause a while before you begin.
X Y Z: follow these pointers for effective speaking and SUCCESS WILLL BE YOURS.

THE NIGHT OWL'S NET

Every night the night owl's meet
Each other to hear and greet
The roll is taken every night
The controllers urge the owls with all their might
The Net controllers are om Vispy on one day
With sister Pervez on the other day
These are the dedicated duo who toil daily to swell the numbers
Sometimes end the net calling cucumbers
Owls call from near and far away every night
To check their sets if they are right
Others stay on to ragchew after the net
Various topics every night are on the net
Now come on boys and girls we can have some fun
With two repeaters under the sun
Sometimes we have some SOB's on call
Who howl and tend to spoil the ball
The first to check is om Bob
Always tries the first place to Hog
The next in line is PDN
Who comes on every night out of his den
The Joker comes off and on
With his jokes he turns us on

To be continued in installments