Competence in making radio contacts. This part of the syllabus is
carried out as a practical assessment by registered assessors and may
be part of a training course. The assessment centre will arrange for you to be tested on this section of the syllabus.In addition they should provide you with tuition on how to carry out the tasks.The
notes given here will give an outline of how to do these, but they are
not an alternative to trying them out your self with some radio
equipment.
8e.1 Demonstrate, using a
VHF/UHF transmitter/receiver; correct tuning in to an amateur FM voice
signal and a data signal such as packet. Read the signal strength meter (where fitted).
On VHF and UHF frequencies for FM are
channelised. This means that you do not need to turn a continuous
tuning knob to move to the correct frequency, rather you turn a
"Clickable" knob that jumps from one frequency to the next. The steps
are usually 12.5kHz on modern equipment, although on older equipment
the steps may be 25.0kHz.
The steps are as follows:
Turn on the power and check the screen is illuminated
Make sure the steps are 12.5kHz
Check that the antenna is connected
Make sure the FM mode is selected
Deactivate
the squelch to make sure there is some background noise and then rotate
the squelch control until there is no noise from the speaker
make sure you are in simplex mode (I.e the repeater shift is off)
Turn the rig to the band you want to listen on.
Listen between 145 and 146MHz for an FM signal
Rotate the clickable knob until you hear a station
If the signal is not on frequency turn on the RIT and tune them in using main VFO control.
Adjust the volume control
Check the strength of the signal using the S-meter if fitted
To tune into a a data signal such as packet you would:
Turn on the power and check the screen is illuminated
Check the antenna is connected
Turn the squelch control until you hear background noise
Turn to the part of the band where data is transmitted (Try 144.800)
Turn on your computer and set it up for packet. Or connect your TNC to the radio.
Listen until you hear a signal or you may see the signal on a the waterfall display of your packet program.
Tune
the VFO until the signal is in the centre of the markers on the
computer display. If you are using a TNC you may need to look at the
display to check you are receiving packets of data.
Turn up the volume control to a level that just allows packets to be seen on the screen.
8e.2 Demonstrate correct operation of a VHF transmitter/receiver in simplex mode. Note: Controls used shall include frequency, squelch and, audio gain (volume). See above
Recall the meaning of signal reports exchanged during a contact.
On speech contacts the report is given as two numbers.
The first number is between 1 and 5. This indicates the readability of the signal:
1 -- Unreadable 2 -- Barely
readable, occasional words distinguishable 3 -- Readable with
considerable difficulty 4 -- Readable with practically no
difficulty 5 -- Perfectly readable
The second number is between 1-9. This indicates the strength of the signal.
The S-meter is often used and you will hear reports such as 5 and 9
plus 40dB. This is taken from the S-meter which usually calibrated from 0
to 9 and then +20, +40, +60dB
When using CW (Morse Code) a tone report is added to the above two. Tone is also given on a 1-9 scale:
1 -- 50/60 cycle a.c very rough and broad 2 -- Very rough a.c. , very harsh and broad 3
-- Rough a.c. tone, rectified but not filtered 4 -- Rough note, some
trace of filtering 5 -- Filtered rectified a.c. but strongly
ripple-modulated 6 -- Filtered tone, definite trace of ripple
modulation 7 -- Near pure tone, trace of ripple modulation 8 -- Near
perfect tone, slight trace of modulation 9 -- Perfect tone, no trace of
ripple or modulation of any kind
Make a simplex radio contact and exchange signal reports.
Listen to other QSOs to discover how a QSO is conducted.
8e.3 Demonstrate, using an HF
transmitter/receiver, correct tuning in to an amateur SSB voice signal
and a Morse signal. Read the signal strength meter.
The initial set up is the same as when receiving FM except that USB or LSB needs to be switched on.
Turn the AGC to slow
Tune to the part of the band used for SSB
Slowly tune across the band until you hear a signal. When you find a signal tune slowly until the voice sounds natural
If the signal is weak you may need to adjust the different gain controls and bandwidth to improve reception.
On SSB the meter will move in time with speech peaks. Look for the peak reading when giving a report.
To tune in a Morse signal set up the radio as above, then:
Turn to CW mode
Switch on the CW filter if installed
Change the AGC to fast
Move to the lower end of the band where Morse is used
Slowly tune across the band until you hear a signal. Carefully tune for an audio note of about 600Hz
Adjust the gain controls for a readable signal. If the signal is subject to interference try to narrow down the DSP filter if fitted. On some radios you can also move the inserted carrier to receive the other sideband of the CW signal.
Here is a link to a typical QSO. Click to listen to the QSO
8e.4 Demonstrate correct operation of an HF transmitter/receiver in an SSB contact. Note: Controls used shall
include frequency, the RIT (clarifier), audio gain (volume), RF gain,
microphone gain and antenna tuner (ATU).
Make an HF SSB voice contact and exchange signal reports.
To call CQ on SSB using the HF bands:
Check the antenna is connected and turn on the transceiver
Switch to the band of interest and move to the SSB end of the band
Roughly tune the ATU for maximum signal
Find a clear frequency and using the lowest power possible switch to CW and press the Morse key
Adjust the ATU for a low SWR ratio on your S meter
Turn back to SSB and turn up the power. Adjust the ATU again if necessary.
Call CQ and then listen for a reply
If the station calls
off frequency, switch on the RIT (clarifier) and tune them in. This
will keep your signal on the same frequency but will move the receive
frequency on receive
Adjust the RF
volume control in conjunction with the AF gain control for best
reception. Often reducing the RF gain and increasing the AF gain will
improve reception.
Alter the
Microphone gain control until the station you are working reports the
best quality audio. Whatever, do not increase the microphone gain too
far as this will overdrive the transmitter and cause your audio to be
distorted
8e.5 Demonstrate a CQ call on VHF/UHF, making a contact and initiating a change of frequency (QSY) off the calling channel.
To give a general call on the calling channel your words should be something like this:
CQ CQ, CQ This is G3QQQ calling CQ and listening
If a station calls you back you should reply with:
G4XYZ (or whatever their call sign) this is G3QQQ. Shall we QSY (Change frequency) to 145.450. I have checked the frequency and it seems to be clear at my end.
If the other station agrees than move to the new frequency and call: This is G3QQQ calling G4XYZ
Connecting a transmitter/receiver.
This part of the syllabus is carried out as a practical assessment by
registered assessors and may be part of a training course.
The main points when connecting a transmitter / receiver are:
Connect
the HF antenna to the ATU, connect the ATU, to an SWR meter and then
connect the ATU to the HF antenna connector on the transmitter /
receiver
Make sure the mains lead is plugged in to the 12V power supply and the 12V output is connected to the transmitter / receiver.
Make sure the microphone is connected and switched on
If you use a key to tune up make sure the key is connected to the transmitter / receiver
If the candidate has any disability that reasonably prevents the
carrying out of these procedures, he or she may talk another person
through the task or describe it to a competent assessor.
8f.1 Demonstrate connecting a transmitter/receiver to a power supply, antenna and feeder. See above
8f.2 Demonstrate, using a λ/2 dipole antenna with adjustable elements,
that the SWR varies as the length of the elements are varied. Set up
the dipole for minimum SWR.
Note: The elements are not to be adjusted whilst transmitting. Correct procedure for a radiating test shall be demonstrated.
This is probably best done on 2m
where the elements are fairly short. You could also use a couple of
adjustable antennas often found on domestic radios where the sections
slide into each other to change the length. Set up the length of the two halves
to about 50cm each in the clear, move away from the dipole and apply a
few watts of power on a frequency of 145.450MHZ , record the SWR.
Adjust the length of the elements until the lowest SWR is achieved. The dipole is now resonant.
If you don't have adjustable antennas
use bare wire and start with 60 cm on each side. Clip off 2cm at a time
from each end until the SWR is about 2:1, then cut off 1cm at a time
until the SWR reaches 1:1 or it start to go up again.You now have a resonant dipole on 145.450 MHz
