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Torbay Amateur Radio Society

Intermediate Licence Pre-course Training Manual

Version: 1.0 January 2019

Version: 1.0 January 2019

CONTENTS

Intermediate pre-course Training Manual

Introduction .......................................................................................... 1

Conductors, Semiconductors and Insulators ....................................... 2

Components & symbols ....................................................................... 3

Projects – working safely ..................................................................... 5

Electrical Safety ................................................................................... 6

Units of Measure & Multimeters ........................................................... 7

License Conditions - Part 1 .................................................................. 8

Operating Procedure & Practice .......................................................... 9

Alternating Current ............................................................................. 11

Capacitors & Inductors ...................................................................... 12

Scientific Notation .............................................................................. 14

Impedance (Z) and Reactance (X)..................................................... 15

Tuned Circuits ................................................................................... 15

RF Oscillators .................................................................................... 16

Diodes & Transistors ......................................................................... 17

Transmitters ....................................................................................... 17

License Conditions - Part 2 ................................................................ 20

Power Supplies .................................................................................. 21

Other Types of Modulation ................................................................ 22

Receivers ........................................................................................... 23

Antenna Matching .............................................................................. 26

Antenna Feeders ............................................................................... 27

Antenna Topics .................................................................................. 28

Propagation ....................................................................................... 29

Acknowledgements ............................................................................ 32

Annex-A

Guidance for Safe and Successful Soldering

Torbay Amateur Radio Society 1 Version: 1.0

INTERMEDIATE PRE-COURSE TRAINING MANUAL INTRODUCTION This book has been produced by the TARS Training Team (Trg Tm) for the use of club members who wish to take part in licence training to gain a UK, Intermediate amateur radio licence. Candidates are required to complete this document prior to attending the practical/examination day.

This work book is the result of ongoing development and candidates’ feedback upon it is always welcomed by the Trg Tm.

How to use this Manual To get full benefit from this manual, the Trg Tm recommend that candidates read each of the relevant RSGB publications – currently entitled ‘Intermediate Licence – Building on the Foundation’ & ‘Intermediate Licence Syllabus’ before seeking to answer the questions contained in this book.

It is of course entirely possible to simply research the relevant answers to the questions and submit the handbook to the Trg Tm. However, this approach will prove inevitably, to be self-defeating. Amateur radio is as much about ‘self-learning’ as anything else. Completing this book correctly will serve to give candidates an excellent indication of their level of knowledge, feedback about weak areas and a good idea of the sort of information contained within current exams.

With the above in mind and at the same time it is also worth noting that there is nothing at all wrong with seeking the advice and knowledge of others within the hobby, however candidates are expected to work on their own and submit only their own work.

I (Candidates Name & CS............................................................................................................. Confirm that the answers contained within this document are all my own work (where applicable). Signed:…………………………………………..Date:………..................... TARS Trg Tm……………………………….…..Date.............…................

Intermediate pre-course training manual


Additional Notes 1. The source reference used to produce this book has been predominantly,

the current ‘Intermediate Licence’ handbook and the corresponding syllabus – neither of which are ‘restricted’ to Trg Tm members only, in fact its highly recommended (at all licence levels) that candidates are familiar with the training syllabi.

2. It should also be noted that the licence handbook is divided into numerous worksheets; twenty-two are what we choose to refer to as ‘theoretical elements’.

The other eighteen or so are referred to as ‘practical elements’ and will be looked at comprehensively prior to and during the practical exercise & exam day organised on your behalf by the Trg Tm.

3. For the sake of variation as much as anything else, some of the questions contained with this book have been randomised, within their own chapters; however, every effort has been made to keep subject matter engaging and relevant.

4. As with all RSGB examinations, no questions are linked; so you will not find it necessary to solve question A in order to find content for part of an equation in question B.



CONDUCTORS INSULATORS & SEMICONDUCTORS Q Label the relevant parts of the following diagram

Q Conductors that have a naturally...…….…. resistance allow the………….movement of available.…………… Commonly used conductors include:

1 3

2 4

Materials that have a naturally…………... resistance, because their electrons are so tightly bound to parent atoms are referred to as: …………..Typical examples might be:

1 3

2 4

Q A semiconductor can be made to act either as an insulator or a conductor, depending on the currents flowing through them as well as how much potential difference (PD) is applied across them. Broadly speaking, they are generally divided into two type of material, which are designated

Ans.…………… ............................& …....................................................

Q Explain in your own terms, from your own understanding the difference between the two:

Ans.....…………..…………..………….……….………….…..........

.......................................................................................................................

Q In relation to ‘biasing’, why is the polarity of the PD important?

Ans...................................................................................................................

........................................................................................................................



COMPONENTS & SYMBOLS ACTIVITY Identify and label the following circuit symbol

ACTIVITY Identify and label as necessary, the following symbols:

Q Diodes have useful properties, which are:

.....................................................................................................................................

......................................................................................................................................

ACTIVITY Identify and label as necessary, the following symbols:

1

2

3

4

5

6 Tuning Coil

7

8



Integrated circuits (IC’s) have never been given a specific representative symbol to depict them in circuit diagrams. With this point in mind, annotate below the sort of ‘symbols’ you might expect to see that indicate the presence of an IC in a circuit:

Q Looking at figure 1, what can be surmised from the corner with the dot, in relationship to the six pins?

Ans...................................................................................

PROJECTS: WORKING SAFELY Please read the advice about soldering contained in annex A. Once you have read it please sign the slip at the bottom of the page to confirm that you understand the inherent dangers involved with soldering.

ACTIVITY Soldering irons can be dangerous if mishandled, list below some of the ways that the risk of burns can be reduced to a minimum:

Q Why are young people deemed to more at ‘risk’ when handling tools etc?

Ans........................................................................................................

Q Why should you always hold a piece of work in a ‘drilling vice’ or clamp and not in your hands when using a vertical/pillar drill?

Ans.........................................................................................................

..............................................................................................................

Q If you are unfamiliar with a particular tool, what should you do with it?

Ans..........................................................................................................

Q Swarf – metal shaving produce during cutting, drilling and milling, along with chips, flakes and other waste should be removed from a work piece and work area by:

Ans..........................................................................................................

1.

2.

3.

4.

5.



ELECTRICAL SAFETY While a lot of the equipment that is used within the hobby is run using Direct Current (DC), some units, and particularly larger home based radios and associated ancillaries are powered by mains voltage supplies The average mains voltage supplied in the UK is: 230 volts (+- 10%) at 50 Hz.

It is not uncommon to come across equipment that has been imported into the UK, from around the world. Please identify the origin of these plugs and label them accordingly.

Q It is good practice to fit what item between a power tool and the outlet socket, and why?

Ans. 1.................................................................................................. .

Ans. 2....................................................................................................

Q In the event of a fuse blowing immediately after it has been replaced, what should your next course of action be?

Ans.......................................................................................................

Q Identify the following circuit symbols



MULTIMETERS Q Multi-meters normally come in two varieties, which are:

Ans. 1..............................................................................................

Ans. 2..............................................................................................

Q Why should you never touch the probes of a multi-meter whilst making a measurement?

Ans. 1...............................................................................................

Ans. 2................................................................................................

Q Basic multi-meters generally measure what?

Ans. 1...............................................................................................

Ans. 2...............................................................................................

Ans. 3...............................................................................................

Q When checking a voltage, the meter and lead are said to be what, in relation to the test piece?

Ans.......................................................................................................

Q In order to check the current passing through a circuit, the meter and leads are said to be what, in relation to the test piece?

Ans.......................................................................................................

Q Briefly explain ‘Kirchhoff’s 2nd Law’

Ans........................................................................................................

...............................................................................................................

Q Potential Difference the key points to remember about measuring PD are?

Ans. 1.....................................................................................................

Ans. 2.....................................................................................................

Ans. 3.....................................................................................................

LICENSE CONDITIONS PART 1 Hopefully, by the time you sit your intermediate exam you will have spent a fair amount of time operating your radio station at HF, VHF & UHF. The Trg Tm recommends you do this for various reasons, not least of which is: isn’t that why you took your foundation licence in the first place? But more than that! It is time well spent in preparation for your next exam; you will already know all the call sign variations within the UK, simply because you will have worked a fair few of them!

You should also be fully aware of the layout and structure of the Region One Band Plan and any notes pertaining to them and you will be a confident, capable radio ‘operator’, able to ‘supervise’ and assist a newcomer to our hobby.



A little reminder:

M3 or M6 XXX Foundation Licence holder in England.

2E0 or 2E1 XXX Intermediate Licence holder in England.

G0 – G8, M0, M1 or M5 Full Licence holder in England.

ACTIVITY List the Secondary Identifiers for the following:

Q As an intermediate licence holder you are allowed to supervise who?

Ans...................................................................................................................

1. Isle of Man

2. England

3. Northern Ireland

4. Jersey

5. Scotland

6. Guernsey

7. Wales

8. Shetland Islands



We are sure that you remember from your foundation course that the Trg Tm emphasised the point that Amateur Radio is not to be used for any sort of commercial purposes. However, you may - upon request - be required to pass messages on behalf of whom?

Ans..........................................................................................................

Operations are not restricted to ones designated home address (QTH), define the following with regard to our Licensing Terms & Conditions:

Q When using the suffix ‘/A’ - pronounced ‘Alt’ - i.e. 2E0TGT/A

Ans.........................................................................................................

Q When using the suffix ‘Mobile’

Ans.......................................................................................................

Q Which overseas administrations recognise and have a reciprocal licensing agreement with the UK regarding intermediate UK licences?

Ans.......................................................................................................

Q What is the defining indication which tells an operator that they stop being simply ‘mobile and become ‘marine mobile’?

Ans.......................................................................................................

..............................................................................................................

Q Are intermediate licence holders allowed to operate from a canal boat?

Ans.......................................................................................................

Q As an intermediate licensee, are you allowed to operate on VHF in a glider?

Ans.......................................................................................................

OPERATING PROCEDURE & PRACTICE Having spent some time operating, particularly on the HF bands you will almost certainly come across some of the ‘odd’ language that operators tend to use, as a form of short hand especially when conditions are poor and getting messages across can at times be marginal.

When conditions are poor messages, questions and answers can be sent and received using an internationally accepted code format – the ‘Q’ code.

There is no requirement to learn all the abbreviations, however it is useful to know some of the more popular, frequently used ones:



ACTIVITY Define the following in the table below:

By now you will also have come to recognise the difference between a simple ‘CQ’ call and a station calling ‘CQ DX’ etc. and if your interest has been piqued enough you will have followed up on your Morse appreciation session to discover that code fans have a language all of their own!

RST (Readability, Signal-strength & Tone) reports are exactly as you learned them during Foundation Training:

Readability: 1-5 1= illegible, 5 crystal clear

Strength: 0-9+ 0= extremely weak signal, 9+ = very powerful

Tone: 1-5 1= Very rough note, 5= Pure DC tone

QSL Cards QSL Cards are unfortunately becoming less and less popular, partly due to the cost of sending cards overseas – although a lot of this is alleviated by the RSGB QSL Bureau - if you are a member of the RSGB. Another factor is the rise in popularity and acceptance of, by many national clubs, of ‘EQSL’s (Electronic QSL Cards).

At time of compilation, the Trg Tm are not aware of any intention by the RSGB to accept EQSL’s as confirmation of QSO’s with regards to Operating Awards and Competitions (this may change in the future).

QRL

QRM

QRN

QRP

QRO

QRT

QRZ

QSY

QSO

QSL

QSB



Sending a QSL is relatively simple, as long as the relevant instructions are followed.

ACTIVITY Explain, briefly below how you would organise and package up a batch of cards to the following destinations: two to Germany, one to Gabon, fourteen to Austria, two to Niger, one to the Falklands and eight to the USA.

Receiving QSL Cards from the bureau is a reasonably simple process too and you need not be a member of the RSGB.

Q What must you send in to your particular QSL manager in order to receive cards?

Ans.......................................................................................................

NOTE: It is regarded as both good operating practice and polite to tell a contact that you do not want a QSL card from him, or that you only use EQSL etc. Keep this in mind when you work a rare or Dx expedition station, where the cost of sending and receiving cards can amount to a huge sum of money!



ALTERNATING CURRENT ACTIVITY Complete the following statements:

1. Amplitude is represented by the..................... of the........................or the

........................of the troughs of a...................... wave.

2. The Peak value is the..................between zero and a.............. or a

...........................peak.

3. The Peak-to-Peak value is the difference between

the.........................and......................peaks of a sine wave.

The RMS (Root Mean Square) value is a kind of...................................... Because of the way that the instantaneous value of a sine wave signal changes the average is not simply half of the peak value; the formula to calculate the RMS value is:

The frequency of an alternating current is the number of times the sine wave goes through its cycle in one second. A cycle is one full transition from zero through a positive peak, back through zero, through the negative peak and ending back at zero, although the start point may not necessarily be zero in every single case!

Q Frequency is measured in ..........…..... abbreviated to……….……

Q What piece of equipment could be used to display a sine wave?

Ans.............................................................................................................



CAPACITORS & INDUCTORS Q Capacitors have the ability to store energy in the form of an electrical

field, this is known as what?

Q The value of a capacitor is determined by three criteria, these are:

Q A capacitor cannot pass what sort of current?

Ans........................................................................................................

Q Generally speaking, capacitors are classified according their dielectric, which could be any of the following:

Q What is the most common format of measurement is used when referring to capacitors?

ACTIVITY Identify the following symbols

Q Capacitors have the ability to store what, for long periods of time?

Ans.......................................................................................................

Q It is good practice to do what when working on equipment containing large capacitors?

Ans.......................................................................................................

Q The unit of capacitance is the:

Ans........................................................................................................

Q 1F equates to:

Ans........................................................................................................

Q 1nf equates to:

Ans........................................................................................................

Q ………... equates to: 1000µf

1.

2.

3.

1.

2.

3.

4.

1.

2.



ACTIVITY Identify the following symbols:

Q The unit of inductance is the

Ans........................................................................................................

Q 1mH equates to:

Ans........................................................................................................

Q ......… equates to: 1000mH

Ans........................................................................................................

ACTIVITY Complete the following statement.

Variable inductors normally come in ……...…...types, those known as

………....coasters and can often be found in

………………………………….............................................................

The other type are often found on circuit board and contain a core made

from the material known as ……….........................................................

SCIENTIFIC NOTATION It is recommended by the training team that you embrace scientific notation, it may at first seem very difficult to comprehend and retain, but remember that Amateur Radio as a hobby is all about perseverance, self-learning and challenging your perceptions and abilities.

Being able to use notation during the calculation of equations makes life a lot easier in the long run, with a far greater chance of arriving at the correct answer than trying to wade through a morass of figures which include lots of zeros etc.

Scientific calculators can be picked up for very reasonable sums and the Trg Tm may well have a few in the stores for candidates to borrow at the club. An in-depth discussion and explanation of the subject is beyond the scope of this document and candidates are well advised to speak to members of the training team about the use of calculators and notation.



ACTIVITY Fill in the answers and commit to memory the following:

Giga

Mega

Kilo

milli

micro

nano

pico

(Note the capitals and lower-case designations)



IMPEDANCE (Z) & REACTANCE (X) Q Further back we learned that when current flows through a resistor it

opposes the flow of electrons this is referred to as resistance. Capacitors also have resistance to current flow and to differentiate between the two, capacitors are said to have:

Ans....................................................................................................................

Q Ohms law can be used to calculate reactance as long as we remember

to use the ……..…....... values for…………….…&…………............

Q Complete the following equation: Reactance (x) =?/?

Ans...................................................................................................................

What happens when we bring the components previously discussed together to form a circuit? each discrete item exhibits its own characteristics, but not only that they also combine together to resist the current flow, this ‘resistance’ is known as:

Ans..................................................................................................................

Q. Complete the following equation: Impedance (?) =?/?

Ans.................................................................................................................

It is probable that you will be required to make some calculations during the intermediate exam – so remember to use the correct value(s) i.e. RMS (Root Mean Square.

TUNED CIRCUITS Complete the following statement:

Q When a ……………. and an ……………... are physically connected

together they form a ……………..... circuit.

Q Explain what happens when the elements within the circuit resonate?

Ans...................................................................................................................

...........................................................................................................................

The components within the circuit can be arranged in various formats - parallel & series.



Q The Series tuned circuit (a) is sometimes referred to as

an……………………...circuit, because it presents a

……………………..... at its resonant frequency.

Q The parallel tuned circuit (b) is sometimes referred to as a ………... circuit, because it presents ......………………………………………….. at its resonant frequency.

Q Parallel tuned circuits can be found, commonly in the construction of

.................................................................................................................

RF OSCILLATORS There are two main types of oscillator, those that produce RF and those that produce Audio Frequencies (AF) – we will look at AF Oscillators later.

Q You should recall that there are three main types of oscillator, which are:

Ans 1.......................................................................................................

Ans 2.......................................................................................................

Ans 3.......................................................................................................

By combining an active component i.e. a transistor with an oscillator containing a crystal it will form a very stable circuits, the transistor maintaining the oscillations and the crystal setting the operating frequency. The down side to such an arrangement is that in order to change frequency it is necessary to change the crystal.

Q A more useful form of oscillator is

the……………………………………………………………………

……………………………………………………..., which can be

used to tune over a wide range of frequencies.

An unstable VFO is highly undesirable for many reasons; list the primary considerations to take into account below:

Ans.1.......................................................................................................

Ans.2.......................................................................................................

Ans.3.......................................................................................................



DIODES & TRANSISTORS Q One of the most common uses of a diode with amateur radio is:

Ans.1.......................................................................................................

Q Roughly how much PD needs to be applied across a (silicon) diode to effectively turn it on?

Ans.1.......................................................................................................

Q The application of the relevant voltage across the diode is known as?

Ans.1.......................................................................................................

Q Complete the following statements:

Once a diode has been ‘switched on’ it has very little..................

Q When building equipment for use within our hobby, it is not unusual to find transistors being used as ………….., ………….... and in ……………………………………… .

Identify and label the following diagram:

Q Define the abbreviation ‘PIC’

Ans........................................................................................................

TRANSMITTERS When visualising a transmitter (TX) as a block diagram, every TX should contain a ……………………... in the final box before the ………… socket.

ACTIVITY Recall the different types of RF oscillator and list their pros and cons:

Ans.1.......................................................................................................

Ans.2.......................................................................................................

Ans.3.......................................................................................................

Ans.4.......................................................................................................

Q The filtering within a microphone limits bandwidth required for voice communications to what?

Ans.1.......................................................................................................



ACTIVITY Complete the following statement:

Where one of the frequencies is an.......................and the other is an RF

signal, the mixing.....................is known as...................and the SUM and the

DIFFERENCE frequencies as..............and.............. WHERE ONE OF

THE ………………….

ACTIVITY Identify and complete the transmitter block diagrams on the following page:

1

2

3

1

2

3

4

1

2

3

4



Q A band pass filter has what type of impedance at frequencies between those known as the ‘cut off’ frequencies

Ans.........................................................................................................

Q Band pass filter can (and should) be found in many transmitters, particularly those that are home built, and always in Single Side Band transmitters. Why?

Ans.........................................................................................................

Q In the simplest terms describe why a SSB signal is more efficient than an AM signal?

Ans.........................................................................................................

1

2

3

4



LICENCE CONDITIONS PART 2 Q As an intermediate licence holder you may apply for a Notice of

Variation of Licence to run a beacon of sorts, what’s the maximum transmitted power permitted?

Ans.........................................................................................................

Q You may also set up a ‘remote station’ control link, with the same TX Power as above. Who else may use you system?

Ans.........................................................................................................

Q When and who may require an Amateur Radio Operator to keep a log over a specified period of time?

Ans.........................................................................................................

Q How often should an operator carry out tests to ensure his or her station is performing correctly?

Ans.........................................................................................................

Q What must an operator ensure he or she is not doing to other radio users?

Ans.........................................................................................................

Q It is a legal requirement of an Amateur Radio operators’ licence to reduce ‘what’ to the satisfaction of an officer authorised by who?

Ans.1.......................................................................................................

Ans.2.......................................................................................................

Q If you move to a new permanent address, who must you inform immediately?

Ans.........................................................................................................

Q How often are you required to validate your licence?

Ans.........................................................................................................

Q How is it possible to ‘lose’ an Amateur Licence?

Ans.........................................................................................................



POWER SUPPLIES Q Compete the following statements:

Primary cells can only be used …..…………….., as a portable and

………………...... power source for ……….... power stations. However

the benefits are far outweighed by the fact that they

Are…………………..and need to be …………………..... of in the correct

manner.

Secondary cells are ………………………... and can be charged

and………………………..... many times. An older type of these cells,

often referred to as ……………….… , contain Nickle and ……………....

are no longer permitted to be imported into Europe due to the extreme

Difficulties in ……………………. and safe disposal of such

………………..…chemicals. NiCads have now been replaced by NiMH

(aka Nims H)…..…………………………….... and also Li Po – Lithium

Batteries.

Q If the transformer in the diagram has a potential difference of 50 volts across the primary winding coil made up of 50 turns and the secondary winding has 150 turns in its coil what is the output voltage of the PSU?

From studying the handbook, you know that transformers only work with AC because the alternating current produces a constantly changing magnetic field, where as a DC current can be viewed as ‘static’. If you were to pass DC through the input of a transformer it would not produce DC in the secondary because its magnetic field is not changing or moving.

In the space below, draw or sketch a copy of the diagram at Fig 64 at the top of Page 49 of the Intermediate Handbook. In particular, pay attention to the different types of wave forms through the power supply. (Read the notes below the diagram and include them in your drawing.)



It is clear from the wave forms shown in the diagram that the pulses of DC being output by the rectifying diode are not suitable to power our equipment! In simple terms the output wave forms are simply not ‘smooth’ enough. To counter this problem one or more large capacitors is inserted into the output.

Q Explain what the capacitor does:

Ans........................................................................................................

................................................................................................................



OTHER TYPES OF MODULATION You may well be aware that there are many different types of modulation in addition to Morse code and telegraphy (voice). These different types of modulation are generically known to all as ‘Data Modes’, of which there are a wide variety. Some, like RTTY (pronounced RITTY) have been in use for a long time, others such as FT8 and WSPR (Weak Signal Propagation Reporter) are new and fairly recent.

Just like the world of computers, data modes are ever changing and at a fast and furious pace, with new ideas and concepts being tried almost every week. You can find a large amount of information on the Internet and there are interest groups for every single format and mode of transmission. In order to use data transmissions you will need at the very least an interface, which can be bought or built for a few pounds depending on the size of you shack scrap box! You will also need some sort of device to decode and display your received signals – most operators tend to use a PC, Mac, Laptop, Ipad or even a mobile phone - you get the idea.

The Trg Tm does not intend to spend a large portion of this workbook discussing the myriad of different types of data modes that can be used, however it is worth noting that the terms and conditions of our licences strictly forbids the use of encrypted or secret codes; when a new format of transmission ceases to be ‘secret’ is not stated, but it is suggested that it is when it is released and freely available to the general public. The TARS contesting team regularly take part in events using RTTY and PSK31 (Phase Shift Keying) etc.

The Trg Tm recommends asking the experienced operators within the team for advice and guidance etc. before diving straight in and ‘giving it a bash’ - with probably poor results.

Club members who are or who develop an interest in Data Modes (and we suggest you do, it’s good fun and you don’t know what you’re missing out on) are advised to buy or borrow the latest publications on the subject, but as noted above the world of data is fast paced and things move on very rapidly. You will also find that some areas of interest overlap in many ways; for instance, it’s not unknown to hear data signals via the amateur satellite service. An additional bonus when using Data Modes is their abilities to cut through noise levels that would quite possibly drown out telephony or even a Morse signal! - a potential life-saver, when operating in an area with lots of QRM etc.

For more information, have a look at the following websites:

https://amsat-uk.org or http://bartg.org.uk/wp/

https://amsat-uk.org/

http://bartg.org.uk/wp/



RECEIVERS Having had a good look at transmitters, it is now a good idea to have a look at their counterparts ‘receivers’. At Foundation level you were expected to remember the three elements or blocks that made up a simple receiver, an example of which is the crystal set – a bit misleading today as they tend to use a germanium diode rather than a piece of Galena!

Q So, what does that diode do?

Ans.........................................................................................................

Q Given that the crystal set is such a simple device, it is not without its short comings – list some:

Ans.1.......................................................................................................

Ans.2.......................................................................................................

Ans.3.......................................................................................................

The TRF receiver (Tuned Radio Frequency Receiver) This unit has the same three blocks as the foundation block diagram, but differs from the crystal set with the inclusion of an RF amplifier at the tuning stage and the addition of a box marked ‘BFO’.

Q Identify and annotate the following diagram:

Q What does the BFO allow the receiver to do?

Ans.......................................................................................................

Q What does BFO stand for?

Ans.......................................................................................................

1

2

3

4



The Super heterodyne Receiver The next type of receiver is usually referred to as the Super Het, they are a significant improvement over the crystal set design in some ways the TRF as well.

ACTIVITY Annotate the following diagram:

Q Explain, in the simplest of terms what’s the result of mixing the incoming RF signal with the local oscillator signal?

Ans.........................................................................................................

................................................................................................................

Q What type of demodulator is required to resolve an FM signal?

Ans.........................................................................................................

.................................................................................................................

Q A diode detector/BFO arrangement can be used to resolve SSB, however a better arrangement in a Super heterodyne receiver is to use?

Ans.........................................................................................................

................................................................................................................

The Automatic Gain Control (AGC) circuit is designed to maintain a steady audio frequency (AF) output regardless of changes in the RF signal at the input to the receiver.

Q Describe below (using a diagram if necessarily) one of the most common methods of achieving such an effect:

1

2

3

4

5

6



Q List the Demodulators required for different modes:

Ans.1.......................................................................................................

Ans.2.......................................................................................................

Ans.3.......................................................................................................

ANTENNA MATCHING The first component of any antenna system is the feeder line. There are several different types in use, but the most common is coaxial cable or coax. Despite appearances all feeders have some similar properties including an impedance value.

Q How is the impedance value of a feeder line derived?

Ans.........................................................................................................

Q What common reference is used when calculating antenna feed point impedance?

Ans.........................................................................................................

Q In general, when you have maximum current flowing in the antenna you can be sure that it’s because?

Ans.........................................................................................................

Q What are the benefits of having a so called ‘matched system’?

Ans..........................................................................................................

Q What happens to the transmitted RF energy from a transceiver if it is attached to an incorrectly adjusted antenna? What could happen as a result?

Ans..........................................................................................................

Q What is the relationship between the mismatch at an antenna feed point and the reflected power that sets up standing waves?

Ans.........................................................................................................

Antenna matching units (AMU’s), antenna tuning units ( ATU’s) or whatever you choose to call them all have similarities in their operation and function. They fall into two main categories; manual and automatic and again, each has certain characteristics that some may find useful, while others may not!

As a general rule of thumb, modern auto ATU’s are either built into a radio or are externally mounted. They offer numerous functions, including band



and frequency tracking, memories and multi antenna outputs. They tend not to like handling mismatches greater than 3:1 (at that level of mismatch over 25% of the transmitted RF is coming back down the feeder line – which isn’t good for any radio!!) Manual ATU’s require greater operator input, but offer greater control as a result, then will deal with higher mismatch ratios that their automatic counterparts but again this is generally not a good thing – it’s better to sort out the antenna mismatch than absorb reflected RF energy in an ATU, besides it’s a huge waste of power!

Q In real terms, placing an ATU in a feeder line to a mismatched antenna is doing what?

Ans.1.......................................................................................................

Working on antennas normally means working outside at heights.

Q What factors should be taken into consideration when doing this kind of work?

Ans.1.......................................................................................................

Ans.2.......................................................................................................

Ans.3.......................................................................................................

Ans.4.......................................................................................................

Ans.5.......................................................................................................

ANTENNA FEEDERS Q What are the stated benefits of using a coaxially constructed feeder over

300 Ω Ladder Line or twin feeder?

Ans..........................................................................................................

Q What major benefits are there to using a balance feeder line over coax?

Ans........................................................................................................

The losses involved in transmission lines are measured in dB (decibels) and like all losses they are cumulative, for calculation purposes this mean they can be added together to give a total.

Q A feed line with a measured loss 10dB being fed with 100 watts of RF indicates that how much is actually reaching your antenna feed point?

Ans........................................................................................................

Q A feed line with a measured loss of 3 dB being fed with 75 watts of RF indicates that how much is actually reaching your antenna feed point?

Ans.........................................................................................................

Remember that losses are cumulative and add up very quickly!

ANTENNA TOPICS Q A step of 3 dB represents a gain of what?

Ans.........................................................................................................

Q 50 watts RF fed into an antenna with a gain of 10dB – what’s the effective radiated power?



Ans.........................................................................................................

Q Which type of antenna can you expect to radiate equally in all directions?

Ans.........................................................................................................

Polar diagrams are used to give a visual representation of the radiation pattern of an antenna. They are normally produced in one of two planes, looking at the antenna from above or from one side.

Q Identify the plots on the charts below and suggest which type of antenna they might represent?



The polarisation of an antenna is determined by its orientation; verticals radiate vertically, horizontal antennas radiate horizontally. RF energy is a form or radiation and is constituted from two fields – an electrical field (E) and a magnetic field (H), which is why RF energy is referred to as ‘Electromagnetic Energy.

As current is fed into the antenna the two fields form a radio wave which then propagates away from the antenna.

Q What is notable about the orientation EH field around an antenna?

Ans........................................................................................................

SAFETY REMINDER: Although it was discussed during Foundation Training, it’s worth reiterating that RF energy can and will cause extremely severe burns, even at relatively low powers.

You should never touch any antenna whilst it is being used to transmit.

Caution should be exercised when using hand held radios in proximity to one’s head – the impact of long-term exposure to even moderate levels of RF energy are not yet fully known. If possible, acquire a hand-held speaker/microphone and carry the radio on a hip belt etc away from your head.

Avoid at all cost looking down the end of a wave guide at anytime, or any other high-powered antenna for that matter.

Anybody with concerns about this issue are advised to contact the RSGB for further advice.

PROPAGATION Propagation is without a shadow of a doubt one of the most investigated subjects within the hobby of amateur radio – and yet nobody has all the answers as to why radio signals move around (propagate) in the way they do!

From your Foundation training you should remember that Frequency and Wave length are related i.e. the higher the Frequency, the physically shorter the RF energy waves become. Hence why 144 MHz is referred to as the 2-metre band, 440 MHz as the 70cm band and 7 MHz as the 40-metre band.

We know that radio waves travel at a particular speed and that it’s entirely possible to use this information to our advantage when calculating antenna dimensions.



ACTIVITY Reproduce below the relevant diagram that allows us to process such information.

Q Using your diagram and formula, calculate the following: An Amateur Radio operator is using the 60m band – approximately what Frequency is the display on his radio showing?

Ans...................................

Q An operator is using the 11m band – what frequencies allocation is this?

Ans....................................

Q What’s the actual wave length for the 446 PMR band?

Ans....................................

Q Which two ways is it possible to receive an HF signal?

Ans.1.......................................................................................................

Ans.2.......................................................................................................

ACTIVITY Complete the following statement:

Many of our signals may be propagated around the globe, bouncing off

the …………….…, which is composed of

numerous.………………….… which are designated the …...…, …..…,

…..… layers. These layers exist in the upper atmosphere and stretch

from approx ……...… out to about ……….… Depending on the

……..... of year, how close are we to Solar ……………... the

Geomagnetic ……...… and a host of other day-to-day variables all have an effect on how our signals actually propagate.

There are plenty of resources on the internet and published in relevant magazines (RadCom & QST etc.) that will assist an operator in judging how well signals are being propagated around the world.



It is worth the time and effort to investigate and make use of these resources, they are becoming more and more accurate due to the numbers of users and the data they are able to provide.

As you should already know VHF & UHF signals (and those above) are generally regarded as ‘line-of-sight’ communications, hence the reason for the ‘Repeater Networks’ that have been established in many countries.

Q On occasion, when conditions are just right VHF & UHF signals maybe subject to what phenomena?

Ans..........................................................................................................

Q What sort of weather can (and does) have a significant attenuating effect on VHF/UHF signals?

Ans........................................................................................................

That’s it! Job Done! We hope you enjoyed completing this manual.

You may well have realised that during the initial production of this booklet we decided not to use the multiple choice (MC) format of questions and answers. Whilst MC serves its purpose well enough for the RSGB examinations, we wanted not only to test your knowledge but also your understanding of the subject matter too, in the hopes that you will have a greater chance of success in your examination.

IMPORTANT REMINDER PLEASE REMEMBER TO SIGN & DATE BOTH THE SIGN ATURE BLOCKS ONE AT THE FRONT AND THE ONE CONTAINED IN ANNEX A. Good luck. We look forward to seeing you on the practical & exam day – Don’t forget to bring this document with you along with some form of Photo ID.

73s Lin M0TCF and the TARS Trg Team.



ACKNOWLEDGEMENTS Thanks to the following club members for their invaluable assistance in the production of this work book:

Torbay Amateur Radio Society i Version: Draft 1

ANNEX-A GUIDANCE FOR SAFE AND SUCCESSFUL SOLDERING The most fundamental skill needed to assemble any electronic project is that of soldering. It takes some practice to make the perfect joint, but, like riding a bicycle, once learned is never forgotten! The idea is simple: to join electrical parts together to form an electrical connection, using a molten mixture of lead and tin (solder) with a soldering iron. A large range of soldering irons are available – which one is suitable for you depends on your budget and how serious your interest in electronics is.

Electronics catalogues often include a selection of well-known brands of soldering iron. Excellent British-made ones include the universally popular Antex, Adcola and Litesold makes. Other popular brands include those made by Weller and Ungar. A very basic mains electric soldering iron can cost from under 5 UK Pounds (8 US Dollars), but you can expect a reasonable model to be approximately 10 to 12 UKP (16 to 20 US Dollars), and it’s quite possible to spend into three figures on a “soldering station” if you’re really serious! You can check suppliers’ catalogues for some typical types of iron. Certain factors you need to bear in mind include:

Voltage: Most irons run from the mains at 230V (110V in the US). However, low voltage types (e.g. 12V or 24V) generally form part of a “soldering station,” and are designed to be used with a special controller made by the same manufacturer. Wattage: Typically, soldering irons may have a power rating of between 15-25 watts or so, which is fine for most work. A higher wattage does not mean that the iron runs hotter – it simply means that there is more power in reserve for coping with larger joints. This also depends partly on the design of the “bit” (the tip of the iron). Consider a higher wattage iron simply as being more “unstoppable” when it comes to heavier-duty work, because it won’t cool down so quickly.

Temperature Control: The simplest and cheapest types don’t have any form of temperature regulation. Simply plug them in and switch them on! Thermal regulation is “designed in” (by physics, not electronics!). These irons may be described as “thermally balanced” so that they have some degree of temperature “matching,” but their output will otherwise not be controlled. Unregulated irons form an ideal general-purpose iron for most users, and they generally cope well with printed circuit board soldering and general inter wiring.

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Most of these “miniature” types of iron will be of little use when attempting to solder large joints (e.g. very large terminals or very thick wires) because the component being soldered will “sink” heat away from the tip of the iron, cooling it down too much. (This is where a higher wattage comes in useful.)

A proper temperature-controlled iron will be quite a lot more expensive – retailing at say £40 or more. This type of iron will have some form of built-in thermostatic control, to ensure that the temperature of the bit (the tip of the iron) is maintained at a fixed level (within limits). This is desirable, especially during more frequent use, since it helps to ensure that the temperature does not “overshoot” in between times, and also guarantees that the output will be relatively stable. Some irons have a bimetallic strip thermostat built into the handle which gives an audible “click” in use: other types use all-electronic controllers, and some may be adjustable using a screwdriver. Yet more expensive still, soldering stations cost from £70 upwards (the iron maybe sold separately, so you can pick the type you prefer). Soldering stations consist of a complete bench-top control unit into which a special low-voltage soldering iron is plugged. Some versions might have built-in digital temperature readout, and will have a control knob to enable you to vary the setting. The temperature could be boosted for soldering larger joints, for example, or for using higher melting-point solders (e.g. silver solder). These are designed for the most discerning users, or for continuous production line and professional use. The best stations have irons which are well balanced, with comfort-grip handles which remain cool all day. A thermocouple will be built into the tip or shaft, which monitors temperature. Anti-Static Protection: If you’re interested in soldering a lot of static-sensitive parts (e.g. CMOS chips or MOSFET transistors), more advanced and expensive soldering iron stations use static-dissipative materials in their construction to ensure that static does not build up on the iron itself. You may see these listed as “EDS safe” (electrostatic discharge proof). The cheapest irons won’t necessarily be ESD-safe but never the less will still probably perform perfectly well in most hobby or educational applications if you take the usual anti-static precautions when handling the components. The tip would need to be well earthed (grounded) in these circumstances.

Bits: It’s useful to have a small selection of manufacturer’s bits (soldering iron tips) available with different diameters or shapes, which can be changed depending on the type of work in hand. You’ll probably find that you become accustomed to, and work best with, a particular shape of tip. Often, tips are iron-coated to preserve their life, or they may be bright-plated instead.

Copper tips are seldom seen these days. Spare Parts: it’s nice to know that spare parts may be available, so if the element blows, you don’t need to replace the entire iron. This is especially so with expensive irons. Check through some of the larger mail-order catalogues. Gas-Powered Irons: You will occasionally see gas-powered soldering irons which use butane rather than the mains electrical supply to operate. They have a catalytic element which, once warmed up, continues to glow hot when gas passes over them. Service engineers use them for working on repairs where there may be no power available, or where a joint is tricky to reach with a normal iron, so they are really for occasional “on the spot” use

Torbay Amateur Radio Society iii Version: 1.0

for quick repairs, rather than for mainstream construction or assembly work.

Finally: A solder gun is a pistol-shaped iron, typically running at 100W or more, and is completely unsuitable for soldering modern electronic components: they’re too hot, heavy and unwieldy for micro-electronics use.

Soldering irons are best used along with a heat-resistant bench-type holder, so that the hot iron can be safely parked in between use. Soldering stations already have this feature, otherwise a separate iron stand is essential, preferably one with a holder for tip-cleaning sponges. Now let’s look at how to use soldering irons properly and how to put things right when a joint goes wrong

Turning to the actual techniques of soldering, firstly it’s best to secure the work somehow so that it doesn’t move during soldering and affect your accuracy. In the case of a printed circuit board, various holding frames are fairly popular especially with densely populated boards. The idea with a holding frame is to insert all the parts on one side (this may be referred to as “stuffing” or “populating” the board), hold them in place with a special foam pad to prevent them from falling out, turn the board over, and then snip off the wires with cutters before making the joints. The frame saves an awful lot of turning the board over and back again, especially with large boards. Other parts could be held firm in a modeller’s small vice, for example

Successful soldering Turning to the actual techniques of soldering, firstly it’s best to secure the work somehow so that it doesn’t move during soldering and affect your accuracy. In the case of a printed circuit board, various holding frames are fairly popular especially with densely populated boards.

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The idea with a holding frame is to insert all the parts on one side (this may be referred to as “stuffing” or “populating” the board), hold them in place with a special foam pad to prevent them from falling out, turn the board over, and then snip off the wires with cutters before making the joints. The frame saves an awful lot of turning the board over and back again, especially with large boards. Other parts could be held firm in a modeller’s small vice, for example. Turning to the actual techniques of soldering, firstly it’s best to secure the work somehow so that it doesn’t move during soldering and affect your accuracy. In the case of a printed circuit board, various holding frames are fairly popular especially with densely populated boards. The idea with a holding frame is to insert all the parts on one side (this may be referred to as “stuffing” or “populating” the board), hold them in place with a special foam pad to prevent them from falling out, turn the board over, and then snip off the wires with cutters before making the joints. The frame saves an awful lot of turning the board over and back again, especially with large boards. Other parts could be held firm in a modeller’s small vice, for example.

Solder joints may need to possess some degree of mechanical strength in some cases, especially with wires soldered to, say, potentiometer or switch tags, and this means that the wire should be looped through the tag and secured before solder is applied. The down side is that it is more difficult to de-solder the joint (see later) and remove the wire afterwards, if required. Otherwise, in the case of an ordinary circuit board, components’ wires are bent to fit through the board, inserted flush against the board’s surface, splayed outwards a little so that the part grips the board, and then soldered.

Opinions vary – but it’s generally better to snip the surplus wires leads off first, to make the joint more accessible and avoid applying a mechanical shock to the printed circuit board (PCB) joint. However, in the case of semiconductors, it's often better to leave the snipping until after the joint has been made, since the excess wire will help to sink away some of the heat from the semiconductor junction. Integrated circuits can either be soldered directly into place if you are confident enough, or better, use a dual-in-line socket to prevent heat damage. The chip can then be swapped out if needed.

Parts which become hot in operation (e.g. some resistors) are raised above the board slightly to allow air to circulate. Some components, especially large electrolytic capacitors, may require a mounting clip to be screwed down to the board first; otherwise the part may eventually break off due to vibration.

The perfectly soldered joint will be nice and shiny looking, and will prove reliable in service. Key factors affecting the quality of the joint are:

• Cleanliness

• Temperature

• Duration

• Adequate solder coverage

A little effort spent now in the soldering the perfect joint may save you-or someone else-a considerable amount of time in trouble-shooting a defective joint in the future.

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Troubleshooting. The solder won’t “take”: If grease or dirt are present, de solder and clean up the parts. Or the material may simply not be suitable for soldering with lead/tin solder.

The joint is crystalline or grainy-looking: The parts forming the joint may have been moved before being allowed to cool, or the joint was not heated adequately (too small an iron or too large a joint).The solder joint forms a “spike”: The joint was probably over-heated burning away the flux.

First Aid: If you are unlucky enough to receive burns which require treatment, here’s what to do:

1. Immediately cool the affected area with cold running water, ice

2. or even frozen peas for ten minutes. 3. Remove any rings, etc. before swelling starts. 4. Apply a sterile dressing to protect against infection. 5. Do not apply lotions, ointments, etc. nor prick any blisters

which form later. 6. Seek professional medical advice where necessary.

IMPORTANT NOTE PLEASE SIGN AND DATE BELOW TO INDICATE THAT YOU HAVE READ AND UNDERSTAND THAT CAUTION IS REQUIRED WHEN USING A SOLDERING IRON AND ASSOCIATED EQUIPMENT:

I ................................... confirm that I have been made aware of the need care when handling soldering irons and other associated equipment. I will endeavour, to the best of my ability, to ensure that I will take all necessary care to keep myself and others from harm when using equipment provided by the Torbay Amateur Radio Society and/or members.

Signed: Dated:

intermediate licence - radiointermediate pre-course training manual torbay amateur radio society 2...

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