ARRL Certification Program
Emergency Communications
CW (Morse Code) Nets

• Limited power at the transmitting location, requiring conservation of energy.
• Limited antenna capability, especially during a windstorm such as a hurricane or tornado, where it is not possible to deploy a full, directional antenna.
• Extreme interference due to foreign broadcast, commercial paging or similar high-output conditions.
• Does not require computer equipment or conditioned power to pass traffic.
• Poor propagation and high static, especially on 40m and 80m, diminishing the use of voice for efficient two-way communications.

During such times, CW can be an effective means of passing traffic.
 

3. Speed isn't everything
1. Good fist at 10 wpm vs poor fist at 30 wpm
On-the-air speed is not an effective measure of effectiveness.  The timely and accurate passing of messages is the measure.  Since accuracy is very important, it may be prudent to slow down the sending speed to make up for adverse conditions.  The key is to send at a speed that the receiving station can pick up comfortably, and with heavy interference and poor signals, 10 WPM may be appropriate.
2. Receiving/Transmitting Techniques
• If your radio supports a high stability crystal option, (otherwise known as an oven crystal, TCXO or temperature compensated crystal oscillator), use it.  It will keep frequency drift to a minimum.
• Tune the receiver/BFO correctly so that you can zero beat with the NCS station and transmit on the correct (same) frequency.  If necessary, use your RIT (Receiver Incremental Tuning) to compensate for receiver drift or frequency offsets.
• Use your passband and/or notch filters to work around adjacent interference.
• If possible (assuming your right handed), learn to send CW with your left hand, use a foot switch to transmit, and write with your right hand.
• Bring one or two fluorescent desk lamps to provide proper illumination at your operating desk.
3. Filters and what works best for what

It pays to use a narrow CW filter to cut out the interference.  Depending on the situation, audio filtering may be sufficient.  Under heavy RF interference, filtering in the IF section should be employed.

One can buy DSP audio filters that processes out the noise being sent to the speaker or headphone.  Some modern radios use DSP audio processing which adequately removes background noise.

Older radios use a crystal element to narrow the IF skirt for receiving CW signals.  Others use DSP processing in the IF stage, which further improves the rejection of nearby RF products.

4. Procedure Signals (Prosigns) for Morse Code

 
B K         Invite receiving station to transmit (break)
CL          Going off the air (clear)
CQ          Calling any station (literally, Come Quick)
K             Go, invite any station to transmit
R             All received OK

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AA          (Separation between parts of address or signature)
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AR          Over, end of message
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AS           Please stand by
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BT           Separation (break) between address and text; between text and signature
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KN 'X'    Go only, invite a specific station 'X' to transmit
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SK           End of contact (send before sending your call)

5. Abbreviations - when and when not to use them