ESTcube: radio details

Technical Details: packet downlink

• Frequency: 437.505 MHz
• Frequency deviation: 3.5 kHz
• Modulation: 2FSK
• Output power: 0.5 W
• Bitrate: 9600 bps
• Callsign: ES5E-11
• Packet format: AX.25 UI frames
• Data payload per packet: up to 239 bytes
• Active: during commisioning period - mainly over the Europe, later also periodically sending housekeeping data in bursts after every 3-4 minutes

Technical Details: CW beacon

• Frequency: 437.250 MHz
• Modulation: CW
• Output power: 0.1 W
• Bitrate: approximately 9 bps, 18 WPM
• Callsign: ES5E/S
• Sending period: 3 to 4 minutes
• Sending format: mostly letter-coded HEX numbers (see conversion table below)

Groundstation requirements

While CW beacon can be received with very simple setup (even small handheld yagi will do) and either CW-capable transceiver or SDR receiver, for packet downlink requirements are more serious. Example minimal setup to receive successfully ESTCube-1 is given as following:

• Yagi antenna with gain more than 16 dBi, preferably a crossyagi
• Low noise preamplifier for 70cm band
• Antenna rotator for both azimuth and elevation
• Transceiver capable to receive 9600 bps packet
• G3RUH-type TNC (e.g. Kantronics KPC-9216+) or SDR with appropriate software (e.g. based on https://www.cgran.org/wiki/ESTCube-1Receiver)
• Packet data could be received also using a soundmodem program - AGWPE, MixW, Linux Soundmodem, MultimonNG etc

Orbit info

TLE-s will be available via NORAD: http://www.celestrak.com/NORAD/elements/

Preliminary TLE-s for ESTCube-1 are following:

ESTCube-1
1 00000U 00000    13127.17171296  .00000000  00000-0  10000-3 0 00005
2 00000 098.1390 205.7730 0134000 220.5400 211.2631 14.71982716000009

How to send reports to es5e@estcube.eu

When sending received data to given e-mail address, please add following information

• Your name
• Your callsign (if exists)
• Skype contact (if desired)
• Location in geographical coordinates or WWL locator
• Time of acquisition of signal (UTC) (day:hour:minute:second)
• Time of loss of signal (UTC) (day:hour:minute:second)
• CW data as an ASCII string (if recieved)
• Packet data as binary attachment or decoded AX.25 packets in ASCII HEX (if recieved)

Interesting and useful for us would be also additional information such as:

• Short description of equipment
• Signal to noise ratio interval (min-max dB) or
• Signal strength interval (min-max S level)
• Qualitative description of radio link (tumbling? abrupt losses?)
• Other comments