Syllabus

ASOC  (Amateur Station Operators Certificate) Examination

Syllabus

1. The examination shall consist of the following two parts:

PART 1 - Written Test

It shall comprise of one paper containing two sections as under:

Section A: Radio Theory and Practice Note - Applicants holding degree in Engineering/Science or Diploma in Engineering and having studied electronics or telecommunications shall be exempted from appearing in Section A of Part-I of the test.

Section B: National and international Telecommunication Union (ITU) Radio Regulations, applicable to the operation of amateur station and those relating to the working of station generally.

PART II - Morse (Only for General Certificate)

Morse reception and sending (8 wpm)

2 Detailed syllabus:

2.1 Amateur Station Operator’s License (Restricted) Examination Part I - Written Test Section A: Radio Theory and Practice:

    (I) Elementary Electricity and Magnetism:

1. Elementary theory of electricity - passive devices (Resistors; Inductors, Transformers, Capacitors) and active devices (Diodes, Transistors).

2. Kirchhoff’s current and voltage laws - simple applications of the law.

3. Conductors and Insulators — properties; units of circuit elements, Ohm’s Law.

4. Inductance — definition of self and mutual inductance;

5. Power and energy - definition, units and simple applications.

6. Permanent magnets and electromagnets - definition, properties and their use.

    (ii) Elementary Theory of Alternating Currents:

1. Sinusoidal alternating quantities - definition of peak, instantaneous, RMS, average values and its simple application.

2. Phase, reactance, impedance, power factor - definition, units and simple applications.

3. Parallel series and series parallel circuits containing resistance, inductance, capacitance; resonance in series and parallel circuits, coupled circuits.

4. Rectifiers, voltage regulation and smoothing circuits - their basic knowledge and simple application.

    (III) Elementary theory of Semiconductor Devices:

1. Diodes and transistors - properties and use of these devices on construction of amplifiers, oscillators, detectors and frequency counters.

    (IV) Radio Receivers:

1. Principles and operation of TRF and superheterodyne receivers.

2. CW reception.

3. Receiver characteristics - sensitivity, selectivity, fidelity, adjacent channel and image interference, AVC and squelch/circuits, signal to noise ratio.

    (v) Transmitter:

1. Principles and operation of low power transmitter, crystal oscillators, stability of oscillators.

2. Basic knowledge about construction of Semiconductor based transmitters.

    (VI) Radio Wave Propagation:

1. Basic knowledge of Electromagnetic Spectrum.

2. Wavelength, frequency, frequency bands.

3. Nature and propagations of radio waves, ground and sky waves, space waves, skip distance, skip zone and fading.

    (VII) Aerials: Common types of transmitting and receiving aerials (antennas).

    (VIII) Frequency Measurement: Measurement of frequency and use of simple frequency meters.

Section B: Radio Regulations:

(a) Knowledge of:-

(i) The Indian Wireless Telegraph Rules, 1973.

(ii) The Indian Wireless Telegraphs (Amateur Service  Rules, 1978 and amendments. 

(b) Knowledge of ITU Radio Regulations as relating to the operation of Amateur Stations with particular emphasis on the following:

Provision of Radio Regulation (2008 edition), Designation of Emission - Appendix-I, Phonetic alphabets and figure code

- Appendix 14, Nomenclature of the Frequency & Wavelength Article 2, Frequency allocation for Amateur Services - Article 5, Interference, measures against interference & tests - Article 15, Identification of stations - Article 19, Distress Signal, Call and Message. Transmissions - Article 30, 31, 32 & 33.

Urgency Signal, Call and Message. Transmissions - Article 30, 31, 32 & 33. Amateur Station - Article 25, Call sign series Allotted to India - Appendix 42.

(c) Standard Frequency and Time Signals Services in the World.

d) The following ‘Q’ codes and abbreviations shall have the same meaning as assigned to them in the Convention.

QRA, QRG, QRH, QRI, QRK, QRL, QRM, QRN, QRO, QRS, QRT, QRU, QRV, QRW, QRX, QRZ, QSA, QSB, QSL, QSO, QSU, QSV, QSW, QSX, QSY, QSZ, QTC, QTH, QTR, and QUM (Ref. Chapter 5 in Part 3). Abbreviations: AA, AS, AR, AS, C, CFM, CL, CQ, DE, K, NIL, OK, R, TU, VA, WA, WB.

Note:-

1. The written test will be of one hour duration. The maximum marks will be 100 and candidate must secure at least 40 % in each section and 50% in aggregate for a pass.

2. There will be No Morse test for restricted grade.

2.2. Amateur Station Operator’s License (General) Examination 

Part I - Written Test 

Section A: Radio Theory and Practice

In addition to the syllabus prescribed for Amateur Station Operator’s License (Restricted) examination, following items shall be included in the syllabus of Amateur Station Operator’s license (General) examinations:

(i) Principles of Communications:

1. Elementary idea of analog and digital communication,

2. Need for modulation; Modulation- amplitude, frequency and pulse modulation,

3. Elementary idea about demodulation.

(ii) Alternating current:

1. Basic concepts on construction of transformers,

2. Definition of Transformer losses,

3. Transformer as a matching device,

(iii) Semiconductor devices and Transistors:

1. Elementary principles of conduction and construction,

2. Symbols and biasing methods.

(iv) Power Supplies:

1. Basic knowledge of half wave and full wave rectifiers,

2. Definition and application of Bridge rectifier, smoothing and regulating circuits.

(vii) Transmitters and Receivers:

1. Elementary principles of transmission and reception of Facsimile and Television signals.

(viii) Propagation:

1. Characteristics of ionosphere and troposphere,

2. Properties of ionosphere layers,

3. Critical frequency and day / night frequencies.

(ix) Aerials:

1. Principles of radiation,

2. Aerials for different frequency bands including aerials for microwaves

(x) Space Communications

1. Elementary principles of communication via satellites.Same syllabus as prescribed for Amateur Station Operator’s License (Restricted) examination. 

The above written test will be of two hour duration. The maximum marks will be 100. A candidate must secure at least 50% in each section and 60% in aggregate for a pass.

Section B: Radio Regulations:

Same syllabus as prescribed for Amateur Station Operator’s License (Restricted) examination.

The above written test will be of two hour duration. The maximum marks will be 100. A candidate must secure at least 50% in each section and 60% in aggregate for a pass.

Part II-Morse Morse receiving:

(Required speed, 8 words per minute)

The test piece will consist of a plain language passage of 200 characters, which may comprise of letters and figures. Test piece may also contain the following punctuations i.e. full stop, comma, semicolon, break-sign, hyphen and question mark. The average words shall contain five characters and each figure and punctuation will be counted as two characters.

The test will be for five consecutive minutes at a speed of 8 words per minute. A short practice piece of one minute shall be sent at the prescribed speed before the start of the actual test. Candidates will not be allowed more than one attempt in Morse reception and sending test, the test may be written in ink or pencil but must be legible. Overwriting will be treated as error. If any correction is required the candidate may strike off the wrong character and write the correct one above the character. More than 5 errors will disqualify a candidate. However if a candidate receives without any error in any part of the passage continuously for one minute duration, he/she will be declared successful in the Morse reception test.

Morse Sending (Required speed, 8 words per minute)

The test piece will be similar to Morse Receiving test for Amateur Station Operator’s License (General) examination. Candidates are required to send for five consecutive minutes at a speed of not less than 8 words per minute. Other conditions are the same as applicable to Amateur Station Operator’s License (General) examination. Note: A candidate shall have to pass both receiving and sending ASOC Exam.

Guidelines Amateur Station Operators Certificate Examination General Guidelines:

1. Any Indian citizen above 12 years of age can appear for the ASOC examination - Restricted or General.

2. The ASOC examination is conducted by Wireless Monitoring Stations located in different parts of India, several times every year. Rules and application formats are subject to change. Either verify them all through official websites or contact a Hams Club before filling up an application form. The filled up application must be sent to the nearest Monitoring Station or to the Monitoring Station, at which the applicant wishes to appear for the examination, one month before the proposed date of examination.

Note:- As per the circular issued by Department of Telecommunications (Government of India) on 11th May, 2020, Registrations for Amateur Examinations and Certificates have become Online.

As of now, the following documents must accompany the application: 

1. An attested copy of birth certificate or school leaving certificate. (The name of attesting officer must be clearly given). Driving Licence, PAN Card, Ration Card, Voter Id card etc. are not accepted.

2. Certificate in support of nationality in the prescribed performa, indicated in Appendix III (The name of signing officer must be clearly given).

5 If the applicant is between 12 to 18 years of age, a ‘No Objection’ Certificate from Parent/Guardian/Head of Institution is to be included.

5. Ref. the notification, given in this blogspot  for more details.

The exam. is of Multiple choice Objective Type. Restricted Grade : 1 hour exam. General Grade : 2 hours exam.

The submitted application on Saral Sanchar Portal would be scrutinised by WPC/WMO, DoT. Upon scrutiny, if any correction is required, officials may advise the applicant through alerts in the provided contact information or through the portal itself. In such cases, correction & re-uploading of documents etc. are possible. This can also be monitored by the applicants as they sign into their own Saral Sanchar dashboard.

Upon grant/rejection of certificates, the same would be intimated to the applicant and the document can be downloaded from portal by logging-in to the dashboard.

Index - Gateway to Ham Radio (Revised edition)

Boxes on: Dayton Hamvention (P 24), Hamfests and places (P 28), The story of Hamfest Official Gavel (P 28), Maidenhead Grid Square (P 30), Community radio Station (P 36), ‘Courage HANDI-HAM System’ (P 45), Amateur Radio promotional schemes in India (P 57), What all can and cannot be legally monitored? (P 86), History of Q codes (P 96), Line voltages in other countries (P 100), Simplex, Half Duplex and Full Duplex (P 110), Conversion table (134), Television standards (P 141), LCDs OLEDs (P 147), Azimuthal equidistant projection (P 164), WPC ruling (full) on online applications (P 183), Experimental Cross Band Repeater (ECBR) (P 202)..... + 150 model questions and answers.

Part 1 The first Amateur Radio clubs, Origin of the word Ham, the formation of ARRL, Acharya Jagadish Chandra Bose and electromagnetic waves, the first radio in Kolkata, growth of Ham Radio in India, ARSI (p 22), Dayton Hamvention (P 24), Hamfests in India (P 25), HFIs and places (P 28)

Part 2 Amateur Radio - hobby or service (P 32), radio pilgrimage Sabarimala (P 33), over to space shuttle Columbia, Idukki bus accident (P 34), with love from Milan (P 35), Community Radio (p 36), the French alliance (p 37), VHF event management? (P 38), Hams in Velankanni (P 39), a new transmitter for Rs. 200/- (P 40) Night Owl’s Net, Hammed all the way (P 42), saving a Swedish pilot, hands of God (P 44), Courage HANDI-HAM System (P 45), Perumon train disaster, where ever Hams are... (P 47), Charminar Net (P 48), Air Net India (P 49), the Lamakaan march, abductors be aware (P 50), a long lost connection (P 51), Ham awareness strides, Zero Beat (P 52), the Latur tragedy (P 53), disaster traffics (P 54), the best SWL (P 55), Queen’s choice, the Kerala flood (p 57), the North East wind, the story of a German short film (P 58), on hold in tears (P 59), 

ASOC topics at a glance (P 60)

Part 3 (P-61) Basic Electronics 

Chapter 1 (P 62) General instructions, shack management – all about PC Board making, soldering/desoldering, measuring units (P 69) measure- ment units and people, LCD and OLED (P 71), 

Chapter 2 (P 72) Radio communication and propagation, cycles, frequency range chart (LF, HF etc.), band chart (P 73), harmonics, ionosphere, and radio propagation (P 74)

Chapter 3 (P 78) Morse code (P 79), keying, modulation (P 81), analogue and digital (P 83), SSB (P 84), bandwidth and channels (P 85)

Chapter 4 (P 86) Becoming SWLs, tuned receiver antenna, BFO (P 89)

Chapter 5 (P 90) BC DXing, QSL Cards, signal reports, SWL/Ham logbook, + Q codes (P 97) 

Chapter 6 (P 99) Electricity, cells, resistors, capacitors, inductors (P 103),

lead Inductance, transformers (P 109),

Chapter 7 (P 111) Semiconductors, covalent bonding, diodes, doping, valves (P 113), transistors, bipolar/FET, ‘ft’, Beta (β) and ‘hfe’, dB (P 117)

Chapter 8 (P 119) Qualities of a receiver, sensitivity, selectivity, Q factor, filters, narrow band, broad band, attenuation, crystal filter, IF stage, high fidelity + S meter (P 122)

Chapter 9 (P 123) Crystal radio, tuned radio frequency receivers, DC receivers, SHR, dynamic range

Chapter 10 (P 128) Making coils, Q factor, toroids, reactances on set frequencies, reactances chart, toroid coding, product detector, squelch, conversion tables (P 134)

Chapter 11 (P 135) Dip oscillator, field strength meter, frequency multiplier, VXO, VCO (7 MHz VCO circuit), VFO, PLL, coherent CW. RF probe circuit and VFO assembling, simplex/half duplex/full duplex (P 141)

Chapter 12 (P 142) Classes of amplification, interstage isolation, intermodulation distortion, parasitic suppressor, amplifiers, modulation, level control, push-pull configuration,

Chapter 13 (P 148) SSB transmission, crystal filters, balanced modulators, side band switching + AM-SSB: comparative performance report

Chapter 14 (P 154) VSWR, reflected wave detector, simple ATU, QRO ATU, SWR meter, power transfer, power transistors

Chapter 15 (P 156) Antennas, dipoles, circular  azimuthal equidistant projection (P 164)

Chapter 16 (P 165) EchoLInk, Peanut, Hamsphere communication, VHF/UHF Communication, AM/CW QRP, SDR

Chapter 17 (P 172) Power supplies,

Part 4 (P-179) (P-178) Rules and regulations, sample questions

Chapter 1 (P 179) Wireless Telegraph Rules - Amateur Service (1978) with recent amendments, online Application (P 183) how to establish a contact (P 210) 

Chapter 2 (P 212) ASOC Exam. syllabus, documents required (P 219)

Chapter 3 (P 221) How to prepare for the exam, 150 model questions and answers (P 222), list of all Wireless Monitoring Stations in India (P 237)

English Articles

Introduction

    These are English translations of an article series that was published in a Malayalam science magazine, 'Electronics For Everybody', from 1994 - 1998. These articles are mostly on home brewing strategies, explained in a simple way, while the book (Gateway to Ham Radio) intends to give all the basics of electronics, along with giving a powerful support to all, for their advancement.

    These articles were written at a time when home brewing was at its zenith and there were components shops in every town in India. Etching PC boards of own design was a craze those days. Soon there had been a paradigm shift, mostly because all types of gadgets appeared in the market comparatively at much lower costs and better performances. One another reason was the changing HF band condition that made low power AM QRPs difficult to strive through. Also, the general enthusiasm towards research and innovation also deteriorated heavily, as the trends changed. 

    

    These articles, however, serve as virtual support to those theories that are established in the book. It may make things more digestible. It will heavily help a new comer, especially if he hails from some arts categories. 

    About me, I come from an English literature background. I could make it, only because there were a lot of friends and seniors ready to offer. What that pushed me forward was the truth that many of the licensees were not science students at all! Yes, in 1991, after 7 years of my entry, I could design and make a 12 Volt HF transceiver of 5 watts output. This 5 watts was enough to contact almost all stations in South India. For a few years I was on that and have contacted far and wide on AM or CW. I thought that writing everything down might help some one else. Shri B Soman Nair, then Chief Editor of the magazine invited the series and it all happened one by one every month. OM Mukund VU2 DRL was the driving force behind. I'm happy, even though I lost seven to ten days every month.

The real satisfaction was when I came to know that these issues were still intact with many new Hams. A lot of people had been asking for old copies of the magazine. I was helpless! But OM Jayachandran VU3BWB and OM Madhu A65DE helped me to recover all those issues, easily. Thank you both. The soft copies in both languages were prepared to be shared free. But everything ended up in creation of a totally new book - Gateway to Ham Radio.

There is a humble request to all the readers - begin doing something only after reading the full texts. Even though you do not propose to assemble anything, the basic information imparted through these articles will certainly widen your knowledge base, considerably. 

Thank you all. Kindly do not forget to contact us in case of clarifications/comments/suggestions. 

Chapter 1 - Radio Signals and Ionosphere

Chapter 2 - BFOs and LSB/USB/CW Signals

Chapter 3 - QSL Cards

Chapter 4 - Receivers and transistors

Chapter 5 - DC Receivers and VFO

Chapter 6 - Oscillators, Transistors

Chapter 7 - Low Power AM transmitters

Chapter 8 - 3.5 MHz doubler VFO

Chapter 9 - Communication Receivers

Chapter 10 - PLL, AGC controlled IF stages

Chapter 11 - Receiver parts

Chapter 12 - Multi band BC Receiver

Chapter 13 - Band pass filters

Chapter 14 - Make custom coils

Chapter 15 - Toroids 

Chapter 16 - Modulation techniques

Chapter 17 - SSB Transmission

Chapter 18 - SSB Generators

Chapter 19 - Crystals and Single sideband

Chapter 20 - Multipurpose Test meters

Chapter 21 - SSB Mixers

Chapter 22 - SSB linear stages

Chapter 23 - RF Power amplifiers

Chapter 24 - Linear Power amplifiers

Chapter 25 - Linear/Output amplifiers

Chapter 26 - QRP Module layout 

Chapter 27 - SWR Protection

Chapter 28 - Simple Dipole antennas

Chapter 29 - Transmitter Antennas

Chapter 30 - More on Antennas

Chapter 31 - Multi-band German Quad antenna

Chapter 32 - Electronic Keyers

___________________________________________________________

                         Chapter 1

Chapter 4 - Receivers and Trascievers

         Bandwidth and Channels

When a High Frequency (HF) signal is Frequency Modulated (FM), the bandwidth it gains is not as small as that it develops during Amplitude Modulation (AM). The difference during FM could be higher by many Mega Hertz. That is one reason why FM transmissions, especially TV stations are known in Channels, instead of being identified by their centre transmitting frequencies. For example, Channel 12 refers to a transmission done between the frequencies of 224 MHz and 228 MHz. This frequency spectrum of channel 12 is allotted for TV transmissions only. In Channel 12, 224 MHz side is used for Audio and 228 MHz side for video - picture is Amplitude Modulated and sound is Frequency Modulated. 

Quality of audio is always better in FM because it is the amplitude of signals that are easily disturbed by atmospheric distortions. At Frequency Modulations with sound only, as per international rules, the Bandwidth is to be held below 200 KHz. One major drawback of Frequency Modulated signals with carrier frequencies at VHF and beyond, is that these signals are accessible only at a small limited range, because at normal conditions VHF signals propagate at a line of sight rule. 

Radio Listeners

Be it AM or FM, the atmosphere is truly filled with many many billions of modulated signals of varying kinds. There are some people, as always, who are keenly interested in listening to as much Radio stations as possible - useful or useless, powerful or weak, English or Malayalam, AM or FM. A Broadcast Commercial Station listener is called a BCL (Broadcast Commercial Listener), while a Ham Radio station listener is called a SWL (Short Wave Listener). There is still another enthusiastic group of listeners called BC Dxers (Broadcast Commercial Dxers). They not only listen but keep track of the Stations general propagation conditions regularly. 'D' here refers to distance, the 'X' here refers to an unknown place (just like in algebra) and the full combination 'Dx' refers to something foreign.

BC Dxing

Anyone who is engaged in broadcast related activities would naturally have a curiosity or an enthusiasm to know how their signals reach at different points on earth, the comparative quality of their signals at different times of the day/night, the condition of the atmosphere and the influences that affects the signals at that time etc. Many Broadcasting companies appoint official monitors all over the world, just for this sort of observations and study. However, an official permission is not required to prepare a signal report of any Commercial Station and send it to the concerned authorities for their evaluation. According to the prevailing practice, broadcasters receiving such amateur Signal Reports respond with Official Acknowledgement Cards (QSL Cards) and sometimes gifts of varying kinds too. QSL Cards are very dear to BC Dxers. Those in QSL Card hunt/collection have even their own Net programs which provide necessary timely information in this regard. In South India, there is a Regular Net (SSB/AM) of BC Dxers on 40 Meters, from 8.30 AM onwards on all Sundays. 

QSL Cards

QSL Cards have no specified size or strict format; they need not even be sent by post. In most countries, there are QSL Bureaus exclusively created for the distribution of QSL Cards. QSL Bureaus sort all Cards to one country/area/individual together and forward it in one bundle, through other QSL Bureaus or Clubs and make sure that they are delivered to the right person safely at the lowest possible expenditure, though a little late. 

Exciting and symbolic comments like 'Good,' 'Excellent,' 'Bad,' or 'Fading' are not that what are expected through a Signal Report. A signal report is prepared at International Standards and at maximum precision. SIO code is the format for BC Dxers (Ref. C-3/1). Here, the word 'Interference' refers to all signals that affect the clarity of the modulation. In SIO, 555 means a powerful Station in its' full strength and clarity. 

  

C-3/1	S = Signal Strength	I = Interference	O = Overall Merit
5	Excellent	Nil	Excellent
4	Good	Slight	Good
3	Fair	Moderate	Fair
2	Poor	Severe	Poor
1	Barely Readable	Extreme	Unusable

In HAM (Amateur) Radio, RST code is the standard (ref. C-3/2). In ordinary HAM Radio chats, only R and S factors are mentioned and signal reports are exchanged like 59+, 57, 46 etc. At the same time, when it come to Morse Code, the quality of tone also is exchanged. There the report comes like 599, 589 etc. 

C-3/2	R = Readability	S = Strength	T = Tone
1	Not Readable	Very weak	-
2	Barely Readable	Weak	-
3	Poor	Barely Copiable	-
4	Readable	Copiable	-
5	Fully Readable	Average	Very Bad
6	-	Good	Bad
7	-	Reasonable	Tolerable
8	-	Fine	Not Clear
9	-	Excellent	Good

Hams usually prepare the RS (Readability and Strength) report from his/her experience; only a few looks at the 'S' Meter (Strength Meter) on the front panel of the Tx (Transmitter). The maximum power a 'S' Meter reads in digit is '9'. Signal strength beyond that is seen in 'db' (decibel). That is, if the meter shows 20 db it will be mentioned as a 59+ signal and in cases it is more than 20 db, '59++' is used to inform that. 

Even though 'SIO' and 'RST' codes are very popular, it is to be noted that they are not enough for an elaborate evaluation and split study of all varying features and characteristics of a signal. In similar critical cases there is the 'SINPO' code for help (ref.C-3/3). 

	Signal Strength	Interference	Noise	Propagation Discussion	Frequency Fading	Modulations		Overall Rating
						Quality	Depth
5	Excellent	Nil	Nil	Nil	Nil	Excellent	Maximum	Excellent
4	Good	Slight	Slight	Slight	Slight	Good	Good	Good
3	Fair	Moderate	Moderate	Moderate	Moderate	Fair	Fair	Fair
2	Poor	Severe	Severe	Severe	Severe	Poor	Poor & Nil	Poor
1	Barely Audible	Extreme	Extreme	Extreme	Extreme	Very Poor	Not at all Satisfactory	Unusable
	S	I	N	P	F	E	M	O
C-3/3                 SINPO CODE

A QSL Card from an average Ham band listener naturally contains a lot of information. Day and exact time of listening, place of hearing, details of the receiver used, specifications of the antenna assembly, self - introduction (in case of fresh contacts) with all necessary profile/bio-data information etc. Always time should be noted in UTC (Universal Time Coordinated) at 24 hours mode (avoiding AM and PM). UTC is Greenwich Mean Time only. Some listeners add pictures too (shack photograph, own picture etc.) in their Cards. 

International Telecommunications Union has divided the globe into Zones and Regions with signifying numbers to them. India is in Region 3 and our Zone is No. 22. These details mostly show the location roughly. Hams and SWLS use longitude and latitude for better location identification purposes - it is sharper. 

Any broadcaster is permitted to use only that frequency or frequency range/band that is allotted to him/her by ITU (International Telegraph Union). The International Telecommunication Union is a specialised agency of the United Nations (UN) that is responsible for issues that concern information and communication related technologies. ITU which was founded in 1865, insists that every Radio Transmitter should have a unique identification code or an open name of its' own. This ITU regulation was in force from the beginning of the previous 20th century itself. 

Earlier, Radio Stations had an option to decide its own name. Slowly, as the number of Radio Stations increased, ITU rules and disciplinary codes also changed accordingly. It ended up with Prefixes to every country. 'VU' goes to India and '457' goes to Sree Lanka. The codes that follow these prefixes exactly show who the operator is. The station code of a VU station is decided by the Union Ministry of Communications. The station name in full is precisely called the 'Call Sign'. There are Call Books that contain all the names of Ham stations within a country. On the QSL Card, a BC Dxer however, has to write the full name of his country, not any of the codes.

Generally, QSL Cards are not sent immediately after listening a station. In most cases relevant details and report are prepared in a special register for that (log book/record), immediately after the chat/conversation. But cards won't move out of the shack until it grows into a pretty good number or the listener finds it convenient to send it out. In case QSL cards are sent at a later date, it is recommended to include that station's later report also, if happened to hear the same station again with a different signal report. Showing serial no. reference in the log book/QSL Card naturally will tell how experienced a particular listener is. In case of Hams, they are bound by law to keep a log book with all contacts marked. 

The SWL version of the same QSL Card is given in pic: C-3/5A. This can be prepared in boxes drawn in a simple note book. If it is Ham Station that is heard, the full call sign of the station should be given. Beyond all the details given in a QSL Card, the listener may specify the name in which he loves to be called. Many Hams are called in the very combination of their station licence; it is like calling someone TG or LN. Fortunately, I got a  better combination (VU2JIM) with my VU Prefix and in Ham circles, my handle  is 'Jim'. One side of the QSL Card is completed with Handle, full address, phone numbers, mail IDs etc.

                      

Sl No.	Date	Starting Time	Ending Time	Freq.	Mode	Stations	Report
001	17.03.2017	14.10	15.20	7040	AM	……………..	59+
C-3/5 A
QSL		Remarks				Wx
Received	Sent	Unusually strong signal today				Sunny Bright

On the next side, write the address of the person to whom the QSL card is sent. There is scope for conveying a few personal information too, along with questions if there are. If QSL cards are sent to persons, it is part of curtsy that we include enough stamps also for a reply QSL Card. Unless one signal report is different from another, a Ham need not be sent another QSL Card. No. '73' used every time signifies love and regards'. '73' comes from what is known as the 'Phillips Code', a series of numeric messages conceived for the purpose of cutting down transmission time on the old land telegraph systems when sending text that is basically the same. 'Wx' refers to atmospheric situations and 'Rx' to receivers ('Tx' - Transmitter). With necessary stamps attached, together with all the cards, anybody can pass it to the QSL Bureaus, if they are at reach. 

Exchange of QSL Cards is actually a traditional ceremony that strengthens the bond of friendship in Ham Radio circles. This is not a rule but a practice. In fact, this is perhaps the most expensive side of this unique hobby. 

Shortcuts in Communication

In all sorts of Radio transmissions, except commercial, importance is for maximum data exchange in minimum time. Where it is data transfer that is more important, certain codes that further accelerates data exchange speed also are used. One example is telegraph in which number/word codes are used. In communication electronics there are codes using English letter combinations, generally called 'Q' codes (because all of them begins with 'Q'). For example QTR for exact time, QSP for a message, QRX for waiting, QSL for understood QSO for conversation and so on. 'Q' codes could be questions or answers, depending on the nature of the situation. Now we know why an acknowledgement card is called 'QSL Card'. 'QSL Card' simply refers to a token of acknowledgement. There are a pretty good number of Q Codes in Ham Terminology. This does not mean that Q Codes are the only short cuts Hams regularly use. Look at the below chart: 

Terminology	Meaning
Home brew	Self made equipment
Shack	Work Station
Ham	Licensed Amateur Radio Operator
Rag chewing	On the air chit-chat
Ticket	License
Rig	Wireless Equipment
Harmonics	Children
Old Man	All licensed Male Hams are called with a prefix OM
YL/ Young Lady	Lady Radio Amateur
SWL	All those who have not yet received a license
Crystal Controlled	Married
Signing Off	Closing the contact
Going QRT/Pulling the Big Switch	Closing the station
LL (Lima Lima)	Landline
QTH	Working QTH = Office, Home QTH =  House
GM/GE (mostly in Morse Code)	Good morning/God Evening
Eyeball QSO	Meeting face to face
Dx/VU land	Foreign country/ India
Silent Key	Die
Field Day	Out door transmission/reception experiments
4 wheeler/2 wheeler/multi wheeler	Car/Bike/Train

Qualities of  a Receiver

For an Amateur Radio hobbyist, SWL or HAM, the most precious of assets would be an ideal receiver. It was in 1925 that the first commercial receiver came out. The interesting thing was that all manufacturers crowded around ‘higher sensitivity’. Their advertisement strategy made the then customers believe that it is highest sensitivity that any receiver most requires. It is only with fear that we could remember those ‘very sensitive’ roaring receivers, which accepted all atmospheric distortions without prejudice to any. Thank God, they are gone!

1) Sensitivity is never a factor that can be ignored, but a good ‘front end’ need not necessarily be best in sensitivity. Sensitivity should be taken as the capacity of a Radio to pick up weak signals, always avoiding maximum distortion elements. Since the noise figure that forms at the Radio front end and in the following RF stages are critical, it is always better to avoid high sensitivity (and thus high noise) receivers. The fact we many times ignore is that weak signals can easily be amplified in the latter stages. 

2) Selectivity, the next top feature of any Radio Receiver, is not limited to the activity of sorting out signals, as we generally assume it to be. It is receiving the right signal in its’ appropriate bandwidth and clarity, avoiding all other signals including harmonics and images. Here, filter circuits are critical. There are generally four types of filter circuits:

1) Low pass filters that let in only signals below a definite frequency,

2) High Pass Filters that let in only signals above a definite frequency,

3) Band stop Filters which block signals of a definite frequency range and 

4) Band pass Filters that let in only a definite range of RF signals. Depending upon the size of frequency range, they are further divided into two - Narrowband and Broadband.

Unless we keep the Q (quality) factor of the tuned circuits in a Receiver at a satisfactory level, increasing the ‘selectivity’ of a Receiver is impossible. An ideal receiver should not only be able to reject all unwanted signals but also be able enough to pull in weak signals without any damage to it. Coming to its’ IF stages, a model receiver with ideal selectivity factors should have strictly defined bandwidth too. The bandwidth of such an IF stage should be 800 Hz for CW, 2.5 Khz for SSB and 3.5 Khz for AM. In double conversion receivers, which propose to avoid all image signals, much care is required in the oscillator stages that handle multitudes of signals. 

3) Fidelity is the next best quality of any receiver. Fidelity hints at the quality of the output audio signal. Hi Fi (High Fidelity) output requires amplifier stages that function exactly at the proposed bandwidths, frequencies and configurations. Any signal, High Frequency or Low Frequency, varies in power as it goes through a processing stage. Even though power is always measured in Watt, in the case of audio, what we consider is how powerfully it appears to us. Audio power is measured in db (decibel). Decibel is a logarithmic unit used to express the ratio of two values of a physical quantity.  Even if a 1W audio signal is amplified 20 times, what we experience could be just a multiplication with 2. We record it with a 2 db note. Even though strength is generally measured through 'S' meter, there is no internationally approved style or method. According to the 'S' meter, the dial is divided into 9 segments of 6 db each.

Communication Radio Receivers

The simplest of Radio Receivers are Crystal radios. It can be made with a few inexpensive parts, such as a piece of wire for an antenna, a coil of copper wire for adjustment (optional), a capacitor (optional), a crystal detector, and an earphone.  Crystal sets produce rather weak sound and must be listened to with sensitive earphones, and can only receive stations within a limited range.

​Generally, Communication Radio Receivers are classified into three. They are:  

1) Tuned Radio Frequency Receivers (TRF)

2) Direct Conversion Receivers (DC) and

3) Super Heterodyne Receivers (SHR). 

​

Tuned Radio Frequency Receivers

A few selective stages, a detector ​and an audio amplifier together make a complete simple Radio. Though they were widely used in the early stages of the Radio, now TRF (Tuned Radio Frequency) Receivers are not in use at all. ​The facts that TRF receivers are good for ​AM ​and ​CW ​signals only​ and mutual interference possibility between various stages are higher, added to the failure of TRF receivers. 

DC Direct Conversion Receivers 

DC Receiver is a simple improved version of TRF receiver. ​This is popular among Radio Amateurs. There are two important reasons for this. The first is that in a DC receiver AM, SSB and CW signals are equally audible without any artificial signal injection. One another reason is that the same oscillator frequency can be used at transmission also.​The simplicity of DC receivers and its discipline in keeping bandwidth always at minimum are added attractions.

DC Receivers have its' on draw backs too. In the case of CW signals, unwanted sidebands are not eliminated in a DC Receiver. Even though DC Receivers pull in signals with poor stability they are not as audible as they are in improved versions of Receivers. In DC Receivers, unless the signal is distortion free, clear and stable it is difficult to demodulate the signal successfully. The worst problem is the interference of other powerful commercial stations. Many times they might appear comparatively stronger than the stations we actually tune to. Using a very highly selective front end we can overcome this interference issues though at a considerable stage gain loss. Using a common ground for all the stages in a Radio also causes interferences from other BC Stations. In spite of all these, it is to be noted that most of the commercial Transceiver manufacturers still use DC receivers at the receiver side.

Chapter 3                                                          Chapter 5