Prosign · CW procedural signal
BT prosign in Morse code
Marks a paragraph break inside a longer transmission. Shares the Morse pattern of the equals sign and is often typed as =.
Morse pattern
-...-
Sent as one continuous shape — no inter-letter gap between the component letters.
Meaning
BT — New paragraph (=)
Notation
Written BT (joined) or = when typed.
When this is used
Used to separate logical sections of a transmission: identification, then BT, then signal report, then BT, then closing. Pacing tool for the listener.
Examples
| On the air | Plain English |
|---|---|
| NAME JIM BT QTH BOSTON BT RIG K3 | Name Jim. (pause) Location Boston. (pause) Rig K3. |
| W1AW DE K1ABC BT 73 | W1AW from K1ABC, paragraph, 73. |
Sending BT
| Letter | Morse | Units |
|---|---|---|
| B | -... | 9 |
| T | - | 3 |
As a prosign, BT is sent as a single character with no gap between the letters: -...-, 13 units long. Sent as two separate letters it would take 15 units, and the extra three-unit gap is exactly what a listener uses to tell the procedural signal from the letters.
| Speed | 5 WPM | 13 WPM | 20 WPM | 25 WPM |
|---|---|---|---|---|
| Time to send | 3.12 s | 1.20 s | 0.78 s | 0.62 s |
What the references say
In ITU-R M.1172, the ITU list of abbreviations and signals for the maritime mobile service, BT is the signal that marks the separation between different parts of the same transmission.
ITU-R M.1677-1 gives the same pattern as the double hyphen (=), used to separate the preamble, address, text and signature of a message.
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