E4C06:

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

  1. -174 dBm
  2. -164 dBm
  3. -155 dBm
  4. -148 dBm

International Morse Code: Alphabet Characters

Letter Morse Code Sound Listen
A • – didah
B – • • • dahdididit
C – • – • dahdidahdit
D – • • dahdidit
E dit
F • • – • dididahdit
G – – • dahdahdit
H • • • • didididit
I • • didit
J • – – – didahdahdah
K – • – dahdidah
L • – • • didahdidit
M – – dahdah
N – • dahdit
O – – – dahdahdah
P • – – • didahdahdit
Q – – • – dahdahdidah
R • – • didahdit
S • • • dididit
T dah
U • • – dididah
V • • • – didididah
W • – – didahdah
X – • • – dahdididah
Y – • – – dahdidahdah
Z – – • • dahdahdidit

International Morse Code: Numbers

Number Morse Code Sound Listen
1 • – – – – didahdahdahdah
2 • • – – – dididahdahdah
3 • • • – – didididahdah
4 • • • • – dididididah
5 • • • • • dididididit
6 – • • • • dahdidididit
7 – – • • • dahdahdididit
8 – – – • • dahdahdahdidit
9 – – – – • dahdahdahdahdit
0 – – – – – dahdahdahdahdah

International Morse Code: Punctuation and Other Characters

Character Morse Code Sound Listen
Period • – • – • – didahdidahdidah
Comma – – • • – – dahdahdididahdah
Question Mark • • – – • • dididahdahdidit
Slash – • • – • dahdididahdit
Equals – • • • – dahdidididah