From ANS-102 and JARL: here is an update about FO-29:
Fuji-OSCAR 29 (FO-29 / JAS-2), the long-lived Japanese amateur radio satellite launched in 1996, continues to operate its V/U inverting analog linear transponder under the control of the Japan Amateur Radio League (JARL). Because the onboard batteries have failed years ago, the satellite depends entirely on solar power and can only function when its solar panels are illuminated.
Current Status (April 2026)
- FO-29 entered a full-sunlight orbit around March 9, 2026. During full-sunlight periods, the satellite experiences no or negligible eclipses, allowing the analog transponder to operate continuously on illuminated passes without scheduled command activations.
- The first full-sunlight window began in early March 2026 and lasted approximately 40 days.
- According to the JARL schedule, this continuous operation ends around April 21, 2026, after which the satellite will enter an eclipse period for about one month.
- A second, longer full-sunlight period is expected from approximately May 20 to mid-November 2026, during which continuous operation should resume.
Transponder Details
- Mode: V/U inverting linear transponder (SSB and CW only)
- Uplink: 145.900 – 146.000 MHz (LSB)
- Downlink: 435.800 – 435.900 MHz (USB)
- CW Beacon: 435.795 MHz (typically 100 mW)
- Digitalker: 435.910 MHz FM (rarely activated)
- The digital BBS (1k2/9k6) remains non-operational.
- Important Restriction: Digital modes are generally not permitted on the linear transponder due to licensing and operational constraints.
Operating Procedure
- During eclipse periods (or the transition out of full sunlight), the JARL control team sends specific commands to activate the transponder at designated UTC times. If the transponder does not turn on within about 2 minutes of the command start, the team terminates the attempt.
- During confirmed full-sunlight periods, no regular command schedule is needed — the transponder stays active whenever the satellite is in sunlight.
- Operators should always check real-time status via AMSAT Live Satellite Status, OSCAR Status pages, or recent community reports, as voltage instability in the aging satellite can occasionally cause unexpected behavior.
April 2026 Specifics
In early-to-mid April 2026 (while still in the March full-sunlight window), expect the transponder to be available on most or all illuminated passes with no fixed on/off times. After approximately April 21, operation will shift back to scheduled command activations until the next full-sunlight season begins in late May.
The scheduled activations for the eclipse period are:
April
24th 22:22~
25th 21:27~
28th 22:11~
May
1st 22:56~
2nd 22:00~
3rd 22:51~
4th 21:55~
5th 22:45~
6th 21:50~
7th 22:40~
8th 21:44~
9th 22:35~
15th 22:19~
16th 23:10~
Amateurs are reminded to:
- Use proper Doppler correction.
- Follow linear transponder etiquette (listen before transmitting, keep signals clean).
- Limit uplink power to avoid overloading the transponder (typically no more than a few watts with a modest antenna).
The JARL page provides the detailed historical and upcoming command schedules for eclipse periods across 2025–2026. For the absolute latest status and any updates from the Japanese control team, monitor the official JARL FO-29 page, AMSAT.org, and AMSAT bulletins.
FO-29’s continued operation nearly 30 years after launch remains a testament to robust engineering and the dedication of the JARL team.
[ANS thanks JARL for the above information]

