In
Earth->Moon->Earth (EME) communication the signal echoed back are so weak
that only very efficient and simple modulation techniques can be used. The
traditional and classical system used by radio amateurs is telegraphy (CW)
where the basic information encoding allows detecting and decoding very weak
echoes. With
the use of computers a new digital system where all the encoding and decoding of
information is done by software has recently became popular in the EME
community. Phone transmissions are
also used but they requires higher signal levels and therefore are only
possible with extremely good conditions and between well equipped
stations.
The following are examples of signals echoed by the moon and collected by
my former antenna system (8 * 39el). The antenna had unfortunately a short life
because destroyed during a snow storm in Feb/2005. All of the recording are in
CW (telegraphy).
The following are instead
signals covering the possible communication modes, all of the examples must be
considered as exceptionally strong signals. Usually what we receive back from
the moon is much weaker.
DL9KR Monster Signal (Fragment from a QSO 4th/May/2008 (815 kb)
JA6AHB calling OK1TEH 13th/Apr/2008 (2118 kb)
In QSO with IK6EIW (recorded by IK6EIW)7th/Feb/2009(1330 kb)
First SSB QSO with HB9Q 19th/Dec/2007 (3101 kb)
In QSO with K2UYH (recorded by SM4IVE) 27th/Dec/2009 (1939 kb)
OE5JFL signal (vertical scale 10dbxdiv) 15/Nov/2008 (382 kb)
Snap shop of my own echo (vertical scale 10dbxdiv) 16/Nov/2008 (557 kb)