How do I send negative numbers or below zero in CW?

Question

Sometimes when operating CW I want to send numbers that are negative. In particular when operating outdoors during the winter and someone asks the temperature, I would like to come back in CW with -5C. For some events like Freeze Your Butt Off, the temperature is a required part of the exchange. I realize that almost always the temperature in Fahrenheit will be above zero, but as a Canadian Ham I would prefer to use Celsius.

The best I have come up with so far is to send M5C, but I am not sure that this will be well understood.

score 6 · Accepted Answer · answered Dec 05 '17 at 23:24

According to Wikipedia there is a code for the hyphen or the minus symbol, − · · · · −. However very few hams are likely to recognize it. In the meantime I would suggest sending "MINUS" or "NEG".

If "Freeze Your Butt Off" ever grows to become a big-time contest, then contesters will work out some efficient way of communicating negative numbers. (Or maybe most everyone will just send "dah" as the "cut number" for zero, similar to the way most signal reports in Morse code contests are "5NN".)

score 1 · Answer 2 · answered Dec 09 '17 at 14:22

1

The dash (-....-) would be the usual way to denote negative numbers. If some HAM does not easily decode this: well, it's time to improve your capabilities :)

answered Dec 09 '17 at 14:22

du00000001

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score 1 · Answer 3 · answered Jan 14 '18 at 19:16

1

You can use Kelvin as temperature scale. https://en.m.wikipedia.org/wiki/Kelvin

answered Jan 14 '18 at 19:16

Amlan Chatterjee

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How do I send negative numbers or below zero in CW?

3 Answers3