K5SO home page

The above audio file is the result of Ben Bailey W4SC
using his SDR-IQ receiver as an IF stage at the EME station
of Joe Demaso K1RQG (32' dish antenna in Maine) to intercept
and record a portion of the impromptu 23 cm EME transmissions
between EME station K5SO in New Mexcio and EME station W6SRI
in California via the moon during the Echoes of Apollo activities. Apollo
Astronaut Bill Anders was connected to K5SO via telephone for the
communcations link. Audio file edited by K5SO.

Photo: 8.6 meter (28 ft) parabolic dish antenna and K5SO on the feedhorn maintenance stand

Moon-bounce amateur radio communications using the moon as a passive reflector at 1296 MHz, pulsar radio astronomy at 436 MHz, H I line (neutral hydrogen) astronomy at 1420MHz, and use of the telescope for absolute-power (radiometry) measurements.

This website provides a description of moonbounce operations and radio astronomy activities at amateur radio station K5SO. In addition, information related to the construction and initial operation of this station is given. Included are a list of stations worked to date by K5SO using moonbounce; information regarding the use of sun noise as a reliable means to monitor system performance; results of our radio astronomy observations; photographs taken during the construction and assembly of the moonbounce station; a brief description with photographs of how the hydraulic dish elevation control system is currently configured; and how the cavity amplifier in a commercial UHF television translator was modified to obtain high power on 1296 MHz for amateur radio moonbounce communications. Construction photos show the assembly of the 28-foot diameter Kennedy parabolic dish antenna, its supporting structures, and other principal components. It is intended that this website will be updated regularly in order to share the moonbounce experience and radio astronomy experience with those who are curious about "ham radio" Earth-Moon-Earth (EME) communications on 23 cm and amateur radio astronomy at 70 cm and 21 cm. Hopefully, some of the information here will be useful in providing ideas to anyone intending to build their own moonbounce stations or radio telescopes by showing how the specific tasks involved were accomplished at this station.

First K5SO EME echoes on 1296.01 MHz were heard by K5SO at 05:30Z April 26, 2005 using 10 watts of rf power and a square septum-polarized feed with circular choke. Current output power is 1500 watts (in shack, 900w at the feed horn); K5SO receives his own echoes from the moon (roughly half a million miles round trip!) at a signal strength of S9, approximately 28 dB above background noise. Echoes return approximately 2.5 seconds after the signals are transmitted owing to the extremely long path length for a round trip to the moon and back for the radio waves, even though signals travel at the speed of light!

Questions may be directed to Joe, K5SO, at