[amsat-bb] AO-73/FUNcube

Jim Heck G3WGM jimlist at zoho.com
Sun Jan 8 19:53:58 UTC 2017


Hi Folks,

I have just switched the sat into Educational Mode, ie transponder plus low 
power beacon when in darkness, transponder off and full power beacon when in 
daylight.

73s Jim G3WGM



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:
https://amsat-uk.org/2016/11/10/eo79-funcube-3-transponder-commences-regular-operation/
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.




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