[amsat-bb] AO-73/FUNcube Mode change

Jim Heck jim at milnet.uk.net
Fri Jan 13 20:59:15 UTC 2017

Hi folks,

  I have just changed the sat into continuous transponder mode. Plan is to switch back to auto mode on Sunday 15 Jan 2017 pm UTC as usual.

Pls see below for FUNcube transponder info

Have FUN with the transponder.

73s Jim G3WGM and the FUNcube team.

AO-73 FUNcube-1 

The transponder is normally operational only when the satellite is in eclipse, ie the solar panels are NOT being illuminated. During weekends (from pm Fridays UTC to PM Sundays UTC) the transponder is operational 24/7. 

When the transponder is switched off, the telemetry beacon is on full power, when the transponder is on the beacon it is on low power. During holidays, eg Christmas, New Year, Easter, etc, the transponder maybe activated for extended periods. Watch AMSAT-BB for announcements which are usually made on Friday evenings (UTC) 

The nominal transponder frequencies are: 
Uplink:   435.150 - 435.130 MHz LSB (Inverting)  

Downlink:   145.950 - 145.970 MHz USB

Telemetry Tx: 145.935 MHz BPSK

(The passband may be up to 15kHz higher depending on on-board temps. Low temperatures give higher freqs!)

FUNcube-2 aka FUNcube on UKube

The FUNcube-2 sub-system continues to operate autonomously and, almost continuously, in amateur mode. The transponder is operational and the telemetry downlink is functioning with

about 70mW output. The FUNcube-1 Dashboard does not correctly display the telemetry but it

does correctly decode the data and uploads it to the FUNcube Data Warehouse from where

it can be examined. Most of the real time data channels are operational and these include

battery voltages, temperatures and ADCS data coming via the main On Board Computer (OBC).

The transponder is interrupted for a few seconds every 2 minutes when the other transmitter

sends its CW beacon and, occasionally, for a few seconds when the main OBC reboots (approx seven times each orbit). 

The nominal transponder frequencies are: 

Uplink:   435.080 - 435.060 MHz LSB (Inverting)  

Downlink:   145.930 - 145.950 MHz USB

Telemetry Tx: 145.915 MHz BPSK

(The passband may be up to 10kHz higher depending on on-board temps. Low temperatures give higher freqs!)

EO79 FUNcube-3

Due to power budget constraints the transponder cannot be operational 24/7 and an orbit specific schedule has been developed. The transponder will commence operation 27 minutes after the spacecraft enters sunlight and will stay on for a period of 25 minutes. This schedule may be modified in future months as a result of experience.

The nominal transponder frequencies are:

Uplink: 435.0723-435.0473 MHz LSB (Inverting)  

Downlink: 145.946-145.971 MHz USB

Further detailed info on EO79 transponder frequencies is at: 


All FUNcube transponders are sponsored by AMSAT-UK and AMSAT-NL. We are very grateful for the assistance given by Innovative Solution In Space Bv, The Netherlands.

More information about the AMSAT-BB mailing list