AMATEUR RADIO
Non commercial use of
radio transcievers
for experimental purposes and general communications.
You MUST be a licenced amateur radio operator to transmit on the
amateur radio frequency bands.
Fred VK2JFB has an excellent introduction to the science of
amateur radio.
He covers where to look, who to contact and how to study for an amateur
radio licence :
CW
Continuous
Wave (CW) or Morse Code is actually the oldest modulation system used.
It has 2 states (DOTS and DASHES) and was used BEFORE voice
communications.
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PSK
Phase Shift Keying
- Very
narrow band mode which is very efficient in poor conditions.
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RTTY
Radio
Teletype. Text communications
Popular frequencies
(MHz) include :
|
3.580 - 3.620
|
21.075 - 21.120
|
144.075
|
|
7.035 - 7.045
|
28.045 - 28.150
|
146.600
|
|
14.080 - 14.110
|
52.075
|
432.075
|
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AMTOR
AMateur
Teleprinting Over Radio - An improvement over RTTY and is based on
SITOR (Maritime Mobile Service)for more reliable use over HF circuits
where fading and noise may cause loss of data.
This mode uses time diversity in which the same signal is transmitted
at different times. Two modes may be used : Mode
B (FEC) - The signal is broadcast twice but not to any particular
station.
Mode A (ARQ) - The signal is
transmitted in blocks and after each block an acknowledgement from the
recieving station telling the transmitting station that the block was
recievied OK or it needs to be re-transmitted.
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PACTOR
A combination of
AMTOR and Packet.
An improvement over AMTOR which is faster and yet has improved error
correction
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FAX
Facsimile
- High resolution image transmission whose resolution greatly exceeds
that of SSTV. This is achieved by slowing down the rate of image
transmission.
Each image may take 4 - 10 minutes to transmit.
WX fax reception
Reception of
marine weather FAX via HF radio (Not amateur radio but interesting to
receive)
Weather maps and warnings for marine craft.
Popular frequencies
(MHz) (USB) include :
| 2.658 |
Charleville |
| 5.100 |
Charleville |
| 5.755 |
Wiluna |
| 7.535 |
Wiluna |
| 10.555 |
Wiluna |
| 11.030 |
Charleville |
| 13.920 |
Charleville |
| 15.615 |
Wiluna |
| 18.060 |
Wiluna |
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SSTV
Slow Scan TV -
Sending colour pictures via radio. Popular frequencies (MHz) include :
|
3.735
|
21.340
|
144.300
|
|
7.040
|
28.700
|
432.300
|
|
14.230
|
52.300
|
MONDAY Nights from 7.30 pm local time to around 9pm
a few local amateur radio operators can be heard on the Saddleback
Mountain repeater
on 146.975 MHz FM transmitting pictures using SSTV.
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PACKET RADIO
Similar
to the internet but uses radio links operated by other
amateur radio operators instead of using commercial telephone lines.
Common packet data protocols are AX25 and TCP/IP.
List of local PACKET radio frequencies:
| FREQUENCY (MHz) |
CALLSIGN |
USE |
LOCATION |
|
LOCAL
|
| 53.100 |
VK2XGJ |
BBS , Satellite Gateway |
Dapto |
| 147.575 |
VK2XGJ |
BBS , Satellite Gateway |
Dapto |
| 147.575 |
VK2AMW-7 |
Node/Digipeater |
Mt Murray |
| 440.050 |
VK2XGJ |
BBS , Satellite Gateway |
Dapto |
|
SYDNEY
|
| 144.850 |
VK2WI |
Node |
Sydney - Dural |
| 145.025 |
VK2PK |
TCP/IP |
Sydney - CSIRO |
APRS
Automatic Position Reporting System - used
to
- Track positions of stations connected to GPS units
-
Reporting weather conditions etc.
Stations
don't connect to each other but use unconnected frames of data which
all stations recieve. These unconnected frames are re-broadcasted by
APRS WIDE DIGIPEATERS usually located on hill tops so ALL stations can
recieve the data.
| FREQUENCY (MHz) |
CALLSIGN |
USE |
LOCATION |
| 145.175 |
VK2AMW-1 |
APRS WIDE Digipeater |
Knights Hill |
| 145.175 |
VK2AMW-2 |
APRS WIDE Digipeater |
Mt. Boyne |
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|
