Support:

Signals Tutor V3

FAQ #1 How to adjust the software for given number of words per minute?


The standard word is 'PARIS'

P .--.
A .-
R .-.
I ..
S ...

By the International Code of Signals chapter 1 section 3:

Dot = 1 unit
Dash = 3 units
Space (time) between dot/dash = 1 unit
Space between symbols = 3 units
space between words = 7 units

PARIS =
10 dots + 4 dashes + 9 spaces between dot/dash + 4 spaces between symbols


For Signals Tutor v3 settings:

Dot = 200ms
Dash = 900ms
Between elements = 300ms (in v1, this is same as Dot)
Between symbols = 900ms
Between words = 2100ms

Total for 'PARIS' = 11.9 sec
+ 2.1 sec between words
= 14 sec

60 sec / 14 sec = 4.3 words, so this is Slightly above 4 words per minute.

Assuming:

dot = x
dash = 3x + 1.5x = 4.5x
(recommendation of the International Code of Signals chapter 1 section 3:
 it is best to err on the side of making the dots rather shorter in their proportion to the dashes)
element = 1.5x
symbol = 4.5x
Then:
PARIS = 10x + 4(3x + 1.5x) + 9(1.5x) + 4(4.5x) = 59.5x

If the space between words = 10.5x, then N 59.5x (N-1) 10.5x = 60,000 msec

=> N words per minute = 857.14/x + 0.15

or x [ms] for dot = 857.17 / (N - 0.15)

i.e.
Words/min      Dot [ms]
     2                  463
     3                  301
     4                  223
     5                  177
     6                  147
     7                  125
     8                  109
     9                  97
    10                 87
    11                 79
    12                 72

Dash, space between dot/dash, space between symbols, space between words to be adjusted as:
dot = x
dash = 4.5x
space between dot/dash = 1.5x
space between symbols = 4.5x
space between words = 10.5x


 

 

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