Q codes - 8a.1 Recall the meaning and the reason for use of the Q codes: QRL, QRM, QRN, QRP, QRT, QRZ, QSB, QSL, QSO, QSY, QTH
Q codes have been used in radio since the early day of radio transmissions.
They start with Q
The second letter for amateur use is usually R,S,T and U
The third letter specifies the precise meaning.
They save time when sending information by Morse code and they are frequently used by phone stations.
Sent as 3 letters they indicate information to be sent.
Sent as 3 letters and a ? they are a question.
QRL = Are you busy? / I am busy with ..... do not interfere
QRM = Are you being interfered with? / I am being interfered with.
QRN =Are you troubled by static? / I am troubled by static.
QRP =Must I decrease power? / Decrease power.
QRT =Must I stop transmission? / I am stopping transmission.
QRZ =Who is calling me? / You are being called by ...
QSB =Does the strength of my signals vary? / The strength of your signals varies.
QSL =Can you acknowledge receipt? / I am acknowledging receipt.
QSO =Can you communicate with ... ? / I can communicate with ...
QSY =Shall I change frequency / Change frequency
QTH = What is your position (location)? / My position (location) is ....
Typical amateur uses of these codes:
I have heavy QRM means I am getting a lot of interference.
I have heavy QRN means I have a high level of static interference
I am running QRP means I am using low power
I am going QRT means I am closing down
There is strong QSB on your signal means your signal is fading up and down
I will send you my QSL card means I will send you a card summarising your report and giving details of my station
I am in QSO with G3QQQ means i am in contact with G3QQQ.
I will QSY 5kHz up means I will move my transmit and receive frequency up 5kHz
My QTH is Birmingham means I am located in Birmingham
Abbreviations - 8b.1 Recall the meaning and the reason for use of the following: CQ, DE, DX, R, RST, SIG, UR, WX.
RST code - 8c.1 Recall the meaning of the RST code, the number of divisions of each of the three items, and their order of merit
To speed up the transmission of Morse messages these abbreviations are used. Some are also used on phone.
Some are turned into a question by adding a question mark.
For example in CW:
G3XXX de GM4XXX. R R R = UR RST 599. UR SIG VG = WX wet and windy= GD DX QSL? QRT= GM4XXX DE G3XXX
Reports are given using the RS (for phone contacts) andRST (for CW) system. Where:
R stands for readabilty from 0 to 5 (R is unreadable to 5 fully readable)
S stands for strength from 0 to 9 (S is zero strength to 9 which is
strong) You will also hear 9 plus 40dBs. This is the reading given on
the signal strength meter on the transceiver.
T stands for tone quality on a CW transmission from 0 to 9 where 0 is a rough note and 9 is a clear tone.
CQ = Calling any station
DE = From ...... (callsign)
DX = Distance (i.e. a distant station for that band at that time)
R = Received you transmission (used in Morse)
RST = Report in CW, R = readability 1-5; S = signal strength (1-9) T=tone (1-9)
SIG =
Signal
UR = "you are" or your
WX = weather.
Typical uses by amateurs:
CQ CQ CQ this is G3QQQ calling means I am looking for any station to call me
CQ CQ CQ de G3QQQ. de G3QQQ means from G3QQQ
CQ CQ CQ DX. The DX means that I am looking for a reply from a distant station.
The WX here today is cloud with some rain means the weather here is ......
Relative advantages of different modes.. - 8d.1 Understand the relative operational advantages of CW, SSB and FM
Other types of modulation -
8e.1 Recall that types of modulation other than CW, SSB and FM are
available to the Intermediate licensee (e.g. packet, PSK31, SSTV and
FSTV). Advantages of different modes:
CW -
Narrow band, so more stations can fit into a limited space.
Low power signals more easily copied than SSB or FM.
Easier to make small portable CW transmitters as they use fewer stages.
Power amplifiers for CW more efficient, so portable equipment uses less power.
Because of narrow bandwidth has a 10 dB advantage over a SSB signal.
SSB -
More efficient than other modes of speech transmission as it does not waste power with a carrier and both sidebands.
Uses a narrower bandwidth (about 2.4KHz) than other speech modes and so more speech stations can fit onto a band.
For portable use, uses less power than AM and FM
Less subject to
selective fading
10 to 12 dB noise
reduction due to bandwidth limiting
FM -
Good quality speech with less distortion
Less prone to interference from buildings, traffic etc. than other
speech modes. Provides improved signal to noise ratio (abt. 25dB to man
made interference).
Well defined service areas for given transmitter power.
8e.2 Recall that several
types of transmission can be generated and received with the use of a
personal computer and a suitable interface. In addition to CW, SSB and FM there are other types of transmission available to the Radio Amateur.
PSK31 -
uses a computer to generate and decode text. Information is entered via
the keyboard and viewed on a computer screen. The key presses are
converted into an audio signal which is transferred via the computer's
sound card to the audio input of a transceiver via an audio
interface such as that produced by Signal Link. Audio tones from the
receiver are routed via the audio interface to the soundcard of the
computer.
SSTV - Slow scan TV. The image
is scanned line by line and converted to an audio
signal. This then goes into the microphone amplifier where it modulates
the carrier frequency. At the receiving end it is demodulated and
builds up a picture line by line. Nowadays computers are usually used
to convert the image into audio and audio into images.
FSTV - This uses a TV type
camera. The signal from it and a microphone are used to generate a
signal which is broadcast on UHF frequencies because it has a very wide
bandwidth.
Digital SSTV image sent by OE1IZO
Most
of the digimodes and SSTV can be generated by a computer. The
computer's sound card is connected to the radio's audio in / out socket
via an interface. The interface can control the audio levels and
isolate the computer and transmitter using small audio transformers
that prevent a DC connection, maintain a correct impedance match and so
reduce interference. They also
have a means of detecting when an audio signal starts and stops. This
enables the transmitter to be automatically switched from transmit to
receive.
The photos opposite show a modern interface from SignalLink.
Good operating practices -
8f.1 Recall that call sign prefixes, station locations and addresses can often be found in call books and from the Internet.
Sites such as QRZ.com include a database of many amateurs throughout
the world. You can enter your basic details for free and access the
details of other amateurs.
There are also books of callsigns giving details of amateurs.
The prefix of a callsign tells you where the station is located. There
are books such as the "RSGB Prefix Guide" which give a list of prefixes.
Most computer logging programs will provide you with prefix information
when you enter the callsign. Most have links to QRZ.com and for a small
donation will enter the details into your log automatically.
8f.2 Understand the concept of sending and receiving QSL cards.
QSL cards go back to the start of
Amateur radio. They provide evidence that you have had a contact in the
form of a postcard, often with a photo of the amateur's QTH or
equipment. The cheapest way to send these is to subscribe to an
organisation such as the RSGB. From time to time you send a bundle of
cards to the "QSL Bureau" where a volunteer covering your
callsign will then sort them into countries and these will be
forwarded on to the organisation in the country who deal with QSL
cards. Cards from other amateurs to you will be sorted and from time to
time placed in a stamped-addressed envelope that you have provide and
sent to you.
Many amateurs now send confirmation of contacts vie e QSL using the Internet.
Evidence in the form of QSL cards is used in claiming various awards.
8f.3 Recall
common international call sign prefixes; EI (Eire), F (France), I
(Italy), JA (Japan), PA (the Netherlands), VE (Canada), VK (Australia),
W (USA), ZL (New Zealand).
Of the many hundreds of prefixes, you have to learn the ones above for the exam.
8f.4 Understand
that there is a competitive element in amateur radio: achievement
awards, DX operation and contests. Recall their basic operating
practices.
Achievement awards, e.g. for contacting country prefixes, ‘squares’ on a map or islands; normally confirmed by QSL cards.
Contests involve exchanging call signs and a serial number or location.
There are a number of competitive
elements in amateur radio. Achievement awards are given for amateurs
providing evidence that they have worked a certain number of countries.
For example the DXCC 5 Band Award is given for working 100 different countries on
each of the 5 bands; 80, 40, 20, 15 and 10m.
The WAB (Worked All Britain) is
awarded to amateurs who have worked, for example, a number of
10km x 10km squares based on an OS map.
IOTA (Islands on the Air) Awards are given to amateurs who have worked a certain number of islands.
