Ian Waugh - A Mariner\'s Guide to Marine Communications

(John Hannent) #1

43G3 (403) (^4071) J3E 5 .0
4417 (421) (^4125) J3E 5 .0 H24
8779 (821) (^8255) J3E 10.0 H24
13137 (1221) (^12290) J3E 10.0 H24
17302 (1621) (^16420) J3E 10.0 H24
22756 (2221) (^22060) J3E H24
Author's explanation and calling procedures:


The above sample of (Cape Town Radio) channels tells you:


The Coast Station transmit and receive frequencies (e.g. CRS transmits on
4417kHz and receives on 4725kHz - CRS Tx frequency always on the
left; Rx on the right).


  • The 'ITU Channel Number' (ITU Channel 421 is pre-programmed into
    your SSB Radio with the correct frequencies -the ITU Channel number
    can be used as a crude gUide to daytime range for sky-wave propagation -
    the channel number equating approximately to the mid-range achievable,
    in miles, for single-hop propagation (i.e. Ch7227 achieves 7200 miles
    plus/minus quite a distance - see Chapter 7).

  • The 'Class of Emission' to be used is J3E' (SSB Voice/Upper Sideband
    (USB)).

  • The CRS transmitter power output in kilo-watts (5 or 10 kw in this
    example).


Calling Procedure on HF RT Channels, e.g:
'Cape Town Radio, Cape Town Radio, Cape Town Radio - this is Motor
Vessel Wizard, Wizard, Wizard-calling on Channel 421 - Over'
MV Wizard this is Cape Town Radio - go Ch403 and standby please,
Over'
'Cape Town Radio this is MV Wizard - Ch403 and standing-by
(Both move to Ch403)
Wizard (x3) this is Cape Town Radio (x3) - Over
Cape Town Radio (x3) this is Wizard (x3) callsign Golf Whiskey India Zulu



  • one link call please, Over
    Wizard this is Cape Town - receiving - go ahead with your details -Over
    Cape Town Radio this is Wizard, call sign GWIZ Accounting Authority is
    (AAIC Code) one link call please to Port Elizabeth (telephone number) -Over
    Wizard this is Cape Town - received - standby
    Wizard this is Cape Town - you're connected, go ahead


MARINE COMMUNICATIONS 49
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