- Bandwidth is the amount of frequency band that is required for each transmission
- Beacons are specially licensed unattended transmitters that radiate a continuous signal to assist with checking of signal propagation
- Channelised means that transmissions take place on specific frequencies or channels
- S (Simplex) is the normal method of Amateur communication where both stations transmit, one at a time on a single frequency
- R (Repeaters) are stations that re-transmit a received signal on a different frequency so as to allow further coverage of the transmission.
- Calling frequencies are designated frequencies to establish initial contact
| Transmission | Frequency |
|---|---|
| CW (Morse) | bottom 100 kHz (i.e. 3.5-3.6 MHz) |
| RTTY (Teleprinters) | 3.6 MHz (3.59-3.62 MHz) |
| SSB (speech) | 3.6-3.9 MHz |
| SSTV (Slow Scan Television) | usually found about 235 kHz from the bottom of the band (i.e. 3.735 MHz) |
| Long distance (DX) CW communication | bottom 10 kHz of 80 Metres (3.50-3.51 MHz) |
| Long distance SSB communication | top 10 kHz of 80 Metres (3.79-3.90 MHz) |
| Simplex | - S10 - S23 use 25 Khz spaced frequencies from 145.250 MHz to 145.575 MHz - followed by the repeater outputs RO - R7 on 25 KHz spaced frequencies between 145.6 MHz to 145.9 MHz |
| Repeater | - R0 is at 145 MHz - R1 - R8 is at 25 KHz intervals from 145.025 MHz to 145.200 MHz |
The various types of transmission are given nominal segments so that you know where to 'look' for your particular interest
| Type | Bandwidth |
|---|---|
| CW sector | bottom 150 KHz (144 MHz - 144.15 MHz) |
| SSB speech | 144.15 MHz - 144.5 MHz |
| open all modes | 144.5 MHz - 144.9 MHz |
- use FM (frequency modulation)
- top of this band Is used for satellite communication
- like frequencies on the lower half of this band is not channelised
| Frequency | Usage |
|---|---|
144.01 MHz |
Moon bouncing |
144.05 MHz |
CW calling frequency |
144.3 MHz |
SSB calling frequency |
144.5 MHz |
SSTU |
144.6 MHz |
RTTY |
145.3 MHz |
s12 |
145.5 MHz |
520 |
40mamateur bands can very busy2mand10mcan be very quiet at times due to propagation or geographical difficulties- it is prudent to call on this calling frequency
- as soon as two way communication has been established one of the stations should ask the other to stand-by
- look for a clear frequency
- ascertained that the frequency is not already busy by enquiring "Is this frequency in use please?"
- many circumstances where only one side of a conversation may be audible
- you may (unwittingly) be interfering with another conversation
- then return to the calling frequency and suggest they change frequency to that chosen frequency
- Self-imposed band planning works well most of the time
- But, there might be odd cases who will decide to talk in the middle of the CW sector
- They maintain there's nothing in the license saying they should / should not be inside the band