Use of abbreviated figures in contests and RST reports
Cut Numbers in CW Telegraphy: Speed and Efficiency in Amateur Radio Contests
During amateur radio contests, operators exchange hundreds of numeric sequences, including signal reports (RST), serial exchange numbers, and geographic CQ zone multipliers. To save time and boost transmission rates in CW (Morse Code), operators employ **Cut Numbers**, substituting long numeric characters with shorter alphabetic equivalents.
1. Cut Numbers Equivalence Table
| Digit | Standard Morse Code | Cut Letter | Sound Pattern (Comparison) |
|---|---|---|---|
| 1 | . – – – – | A | . - (instead of . – – – -) |
| 2, 3, 4 | Standard | — | Not cut |
| 5 | . . . . . | E | . (rarely used as 5 is already short) |
| 6, 7, 8 | Standard | — | Not cut |
| 9 | – – – – . | N | - . (instead of – – – – .) |
| 0 | – – – – – | T | - (instead of – – – – -) |
2. Practical On-Air Examples and CQ Zone Applications
When expecting numerical data in a contest environment, receiving an alphabetic character is automatically interpreted as its numeric cut equivalent. Modern contesting software (such as N1MM, Log4OM, or WriteLog) automatically translates entered cut letters into digits.
- Signal Reports (RST): Instead of standard
599, operators almost universally send5NN(orENN). - Serial Numbers: Transmission of
599009is routinely condensed to5NNTTN. - CQ Zones for Europe and Bulgaria (e.g., CQ WW Contest):
- Zone 20 (Bulgaria – LZ, Greece – SV, Turkey – TA…): Rather than sending
59920, operators routinely send5NN2Tor5NNT0(whereTsubstitutes for0). - Zones 14, 15, 16 (Western, Central & Eastern Europe): Instead of
59914,59915, or59916, operators send5NNA4,5NNA5, or5NNA6(whereAsubstitutes for1).
- Zone 20 (Bulgaria – LZ, Greece – SV, Turkey – TA…): Rather than sending
Operator’s Tip: Use cut numbers primarily for predictable exchange patterns (such as
5NN, 5NN2T for Bulgaria, or standardized zone multipliers). When sending unique serial numbers under poor band conditions, excessive cutting can cause ambiguity and require repeats.
