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Intermediate Course
23/08/2014
This week..
• Introduction to Intermediate Course
• Safety
• Soldering
• Construction of Simple DC Circuit
Introduction to Intermediate Course
Week 1
Week 2
Week 3
Week 4
Club Night
Week 5
Week 6
Week 7
Session 1
Session 2
Session 3
Session 4
Session 5
Session 6
Session 7
Session 8
Exam
Exam &
Revision
23/08/2014
30/08/2014
06/09/2014
13/09/2014
16/09/2014
20/09/2014
27/09/2014
04/10/2014
TBC
Hour 1 (Theory)
Intro, Safety,
Soldering
Technical Basics / Components
pt 1
Technical Basics /
Components pt2
Recievers
Measurements
Operating
Practice
EMC, Propagation
Antennas and
Feeders
30minutes
revision
Hour 2 (Practical
Items)
Simple DC Circuit
Measure resistors
Diode and Transistor
Project
VFO
revision
Exam
Transmitters 13A plug / PL259
Introduction to Intermediate Course
• 50 Watts of Power – but note there are exceptions!
• Microwave Frequencies: 1.3GHz (23cms) - 250GHz
• Unattended Operation
• Fast Scan TV
• Build your own Transmitters
• Some remote control
Introduction to Intermediate Course
• Intermediate has more frequencies.
• Note the exceptions on power limits, and
geography
• Some are ERP limited freqs
• Not all are 50W
• Provided in the exam, remember to use it.
Safety
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Soldering
Use of hand tools
Working at heights
Electricity
RF
Safety
• Soldering
Keep soldering iron in stand to avoid contact with skin when not in use.
Make sure soldering is done in well ventilated areas. Avoid breathing in
fumes as they can cause breathing problems particularly to asthmatics.
Eye protection MUST be worn to avoid solder splashing into your eyes.
Safety
• Use of hand tools.
Work in tidy area, away from body to avoid injury.
Handle tools with care. They can cut face or hands if used incorrectly.
Secure any items if you are to saw, drill or file them. Items can spin when drilled or
slip/move while being worked on which can cause injury.
When using a drill ensure the chuck key is removed before using it, else it may fly off!
Safety
• Use of hand tools. Cont…
When drilling protective eye wear MUST be worn to avoid swarf from hitting
your eyes.
Use a centre punch when drilling to help prevent the drill slipping when making the hole.
Bench mounted drills are safer to use than hand drills due to them, allows you to keep
Hands well away from danger area. Also gives more control. (Still need to wear eyewear
And remove chuck).
Safety
• Working at heights
When working from ladders you MUST have a ratio of 1:4.
Example. Ladder in image is 1m away from the wall and 4m high.
Make sure when using a ladder that it is;
1. Secured at the top or held by an adult at the bottom to avoid slipping
2. Do not over reach, you don’t want to fall off.
3. Hard hats should be worn when working at height or around others working
at height
4. If you are going to need tools while working at height its best to wear a tool
belt or another tool carrying device. Also prevents objects falling.
Safety
• Electricity
Take note of overhead cables when using ladders and putting up antennas. Either
can either cause arcing or come into contact with cables and will result in a dangerous shock
Use the correct fuse. Remember Current = Power / Volts, where Volts is 230v.
Example 120watt PSU – 120/230 = 0.5 Amps
Residual Current Devices (RCD) gives you better protection then just using conventional fuses.
RCDs will detect currents to earth of about 30mA where as a fuse will only blow at several amps
And only when there is a short circuit. (Live to Neutral or Live to Earth)
Remember if you are to work on equipment which has large or high voltage capacitors you need to discharge
Them first, as they can store dangerous electric charges.
Safety
• RF
The main health effect of exposure to electromagnetic radiation is heating of
body tissue.
Guidance on safe levels of RF radiation is available from government and
international bodies (HPA – Health Protection Agency and ICNIRP- International
Committee on Non-Ionising Radiation Protection)
DO NOT look down a microwave frequency waveguide or to stand close to or in front of high-gain antennas as
they may be in use. Your eyes are vulnerable to heating. The focus of the waveguide
Of a microwave enhances the heating effect to a smaller area of the body.
Soldering
•
What is soldering?
Soldering is a method of joining metal wires and components using a hot soldering iron to melt the solder
Solder contains flux which is to help the solder flow and to prevent a layer
Of oxide forming on the areas being joined.
Not all metals are easy to solder. Tin, copper, and brass solder well, where
As aluminium and stainless steel require special techniques. This usually will
Not be a problem when building circuits or soldering PL259s for example.
You should always keep the soldering iron tip clean. This is to remove oxide.
To prevent oxide and to help the heat conduction, the iron tip should be
“tinned”. This is why you should tin wires before soldering them onto connections.
Soldering
When making solder joints they should be made reasonable quickly to avoid damage to components. Leaving
the iron on the joint too long can cause “cold/dry” solder joints.
• Construction of Simple DC Circuit
Materials and Components
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Block of wood 10cm by 10cm
Small bulb holder
Bulb
Resistor (R1) 2.2ohm – Red Red Gold
Resistor (R2) 470ohm – Yellow Violet Brown
Drawing pins x 5
AA battery holder
Single Core wire (around 20cm)
SEE PAGE 8 in your book.
• Construction of Simple DC Circuit
Layout
Push into the board the pins
In the layout shown.
• Construction of Simple DC Circuit
Solder R1 and R2
Place Bulb holder on board
• Construction of Simple DC Circuit
Layout
Solder into place the four wires
Notice the wire in the bottom right
Is only solder to one pin.
• Construction of Simple DC Circuit
Layout
Solder on the Positive (+) and
Negative (-) wires from the battery
holder
• Construction of Simple DC Circuit
Layout
Put Batteries into holder and put
Bulb into holder
• Construction of Simple DC Circuit
Layout
Touch wire to pin to create the circuit
• Construction of Simple DC Circuit
Layout
Make sure you put your name on the
Board.
G
F
A
Also label up the board.
E
B
Paul
M0PFX
X
Y
D
-
+
C
• Next Week
Technical Basics and Components Part 1
Measuring Resistors..