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

installation}. If you forget to tune, you may damage the Antenna Coupler

when you press the PIT switch and put foil power into the coupler}.

7 Transmitter Power Output: Can range from 10 watts {low power}
to t200 watts {high power}, depending on equipment fitted. Not all
sets offer Medium. The higher the power, the greater the range at
Medium Frequency (MF), when ground wave propagation is being
used. Transmitter power output does not affect range when using sky-
wave propagation at High Frequency (HF) {though receiving stations
may hear a louder signal where higher power is being used}.

Problem 1. My transmitter always selects H3EI AM automatically,

when I press the 2182kHz button!

Answer. Prior to the final introduction of the GMDSS (1 Feb. 1999),

H3E was the correct class of emission for 2182kHz - withJ3E being

correct for all other working frequencies. Many transceivers are still

programmed to go automatically to H3EI AM when the 2182kHz

button is pressed - so you have to selectJ3E/USB/SSB manually.

Problem 2. When listening to calls on 2182kHz I often hear a loud

tone on top of the voice of the person speaking!

Answer. The transmitting station is using H3E, not J3E, and his

transmitter programming for 2182kHz is slightly different from your

receiver programming for the same frequency. You can solve this by:

(i) using the Clarifier (see 10 below) to tune to the dead-beat or (ii)

change to H3EI AM on your own equipment. Your receiver will then

lock-on to the exact frequency being received (but - do not transmit

using H3E or you will be compounding the problem for others).

Problem 3. My equipment does not offer the full Class of Emission

selection when I want to change frequency.

Answer. Some equipment requires you to enter frequencies {step 5

above} before selecting Class of Emission (step 4), and may only let

you select the correct class for the frequency entered. Other

manufacturers require the information in the order shown above.

Working frequenciesl channels for Coast Stations, and intership

frequencies in the HF bands, are listed in ALRS Vo!. 1 (see Chapter

4 for working examples from ALRS Vo!. 1). A guide to intership

channels in the MF IHF bands is also included at Appendix IX.

MARINE COMMUNICATIONS 141