Category: Ham Satellite news

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Ham Satellite news Telemetry

UMKA-1 SSTV over Stockholm 2025-08-30

The UMKA-1 satellite has turned on it’s SSTV transmission on 437.625 MHz FM Robot 36-mode. Strong downlink that should be possible to receive with a simple yagi without elevation.

Equipment used:

  • RX at 437.625 MHz FM
  • 2 x 13 el LFA X-Yagi (InnovAntenna) on at horizontal polarisation during this pass
  • AlfaSpid RAS az/el rotor
  • LNA Mini-70 from SHF Elektronik
  • LMR-400 coax
  • RTL-SDR v3
  • SDR-Console v3 with doppler correction of downlink and satellite tracking, rotor control
  • PstRotator for rotor control interface between SDR-Console and RAS controller
  • RX-SSTV v2.1.5
  • VB-Cable: virtual audio cable for piping audio from SDR Console to RX-SSTV. Set to 96 kHz and 16 bit.

Short video from the pass:

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Ham Satellite news

Ten-Koh-2 with linear transponder and 5 GHz beacon

Ten-Koh-2 is a satellite planned to be released from ISS later this year (2025). From several sources (see below) we can read that it will include linaer VHF/UHF transponder and a 5 GHz beacon.

From IARU:

  • Transponder uplink 145.895-145.935 MHz
  • Transponder downlink 435.875-435.915 MHz
  • Experiment downlink on 435.895 MHz
  • CW beacon 5839.000 MHz

More information:

Categories
Ham Satellite news

JAMSAT to develop multi-mode transponders for CubeSats

From ANS-236:
The Japan Amateur Satellite Association (JAMSAT) has announced the launch of the “Blueberry JAM” initiative, a new project to design and build an open-source multi-mode transponder for CubeSats. A kickoff meeting was held on May 3 with 15 participants, marking the start of what is envisioned as a flagship development effort for the organization.

The Blueberry JAM project centers on creating a versatile linear transponder that can be integrated into 1U CubeSats, while also being scalable to larger 3U and 6U platforms. The design is intended to support both traditional linear operation and potential digital enhancements, such as delay modes and data handling. The first demonstration unit—an engineering model—is targeted for completion by mid-2026 and will be offered to universities and satellite developers for potential flight opportunities.

Jerry Buxton, N0JY, AMSAT VP-Engineering commented, “AMSAT-NA is excited to see the Japan Amateur Satellite Association’s commitment to open-source development and collaboration with amateur satellite organizations around the world with their Blueberry JAM initiative.

“We are pleased to offer our help in this collective effort by providing JAMSAT with any schematics and documentation from AMSAT’s open-source/open-access projects developed to date as well as those being introduced this year.

“This includes our flight-proven LTM-2 Linear Transponder Module that has flown successfully on satellites deployed by two world-class universities and currently still operating on MO-122 and MESAT1. LTM provides telemetry downlink support for the host science missions and satellite health, as well as direct control of the LTM amateur radio usage. A third university is set to carry the latest version of LTM, which will fly on GOLF-TEE and Fox-Plus, on their upcoming mission that is currently under construction.”

A core philosophy of the project is openness. JAMSAT has pledged to make the development process, design documents, and results available to the amateur community. Hardware costs are expected to be covered by JAMSAT, while individual participants will bear their own incidental expenses. By sharing the design broadly, the group hopes to encourage adoption by multiple satellite missions, with a goal of eventually deploying the transponder on as many as 10 spacecraft.

Technical discussions during the kickoff highlighted the demand for new linear transponder capability in amateur satellites, as well as recognition that digital features will be important for future operations. Considerations include dual-channel command and data handling, efficient microcontroller use, and antenna and power system constraints inherent to CubeSats. The team also noted the potential to establish a ground-based test station to exercise the transponder under realistic conditions before flight.

Buxton also said, “We are also very happy to share AMSAT’s work on its upcoming SDR GEN-2, an SDR that provides all-mode functionality and continuous coverage from 144 MHz to 6 GHz providing “Five & Dime” capability in a format to fit 1U or larger CubeSats.

“We look forward to supporting JAMSAT in promoting more international collaborations that continue to Keep Amateur Radio in Space!”

Coordination for the project will be managed initially through mailing lists, with Slack and other online tools supporting more detailed technical exchanges. Meetings will be held on an ad-hoc basis until a regular schedule is established. Participants also suggested supplementary seminars to review background information and prior work for the benefit of newer contributors.

By positioning Blueberry JAM as a fully open-source design, JAMSAT hopes to strengthen international collaboration and demonstrate Japan’s continued leadership in the amateur satellite community. With a development horizon stretching into 2026 and beyond, the project has the potential to become a cornerstone payload for future CubeSat missions and to provide valuable new communication opportunities for amateur operators worldwide.

[ANS thanks JAMSAT and Jerry Buxton, NØJY, AMSAT VP-Engineering for the above information]

Categories
Ham Satellite news

VGC N76 HT with satellite tracking and doppler control

Over the Youtube channel Ham Radio Crash Course Josh Nass gives a demo with the latest firmware and app for handheld (HT) radio VGC N76 (aka Btech UV-Pro and as a mobile version N7600).

It is important to note that these are not full duplex radios. The general rule is that you must here yourself on the downlink of the satellite in order not to cause interference. But the implementation of doppler control via an Android or IPhone app is kind of unique for amateur radio HTs.

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Ham Satellite news Members news

Open letter from AMSAT-SM regarding development of a full duplex handheld

Update 2025-08-30:

Three (3) out of 12 manufactures sent me an answer. One of these I will continue to work with. I can not give any more information at the moment, but stay tuned for updates.

Final update 2025-11-08:

Unfortunately the manufacture I had a discussion with will not produce a full duplex HT with better filters.

Many of us in the AMSAT community is waiting for a new handheld radio with full duplex FM capability. AMSAT-SM group in Sweden has sent an open letter (e-mail) to the following amateur radio manufacturers:

  • Icom
  • Kenwood
  • Yaesu
  • Alinco
  • Baofeng
  • TYT
  • Wouxun
  • Retevis
  • AnyTone
  • QYT
  • Radtel (added 2025-08-17)
  • Verotelecom – (added 2025-08-18)

And the letter/e-mail:

Open Letter from the AMSAT-SM Group in Sweden to Amateur Radio Manufacturers Regarding the Development of a Full Duplex Handheld Amateur Radio

Dear Sir or Madam,

In recent years, we have seen the release of many new handheld amateur radios from both established manufacturers such as Icom, Kenwood, and Yaesu, as well as from newer, smaller manufacturers, often based in China. These radios frequently include advanced features such as VHF/UHF FM operation, APRS, TNC, USB-C charging, GPS, Bluetooth, and more.

However, one key capability is consistently missing: true full duplex operation – the ability to transmit on one band while simultaneously receiving on another, without desense. For example, transmitting on VHF while receiving on UHF, or vice versa.

We at AMSAT-SM believe there is a significant and growing market for such a radio among amateur radio operators worldwide. A particularly important group consists of operators who use amateur radio satellites, for whom full duplex operation greatly enhances communication and usability. These operators are also prepared to pay a premium for a handheld with this functionality. At present, no current handheld model offers full duplex capability. Instead, many satellite operators rely on discontinued radios such as the Kenwood TH-D72.

We therefore respectfully request the development of a new handheld amateur radio with true full duplex capability between VHF and UHF (e.g., transmit on 145 MHz and receive on 435 MHz without desense, and vice versa).

Additional features to support satellite operation would also be very welcome. For example, the AnyTone AT-D878UVII includes satellite tracking functions, but unfortunately lacks full duplex capability.

We strongly believe that a handheld radio with these capabilities would be highly valued by the amateur radio community and represent a unique opportunity for any manufacturer willing to take the lead.

Sincerely,
AMSAT-SM Group in Sweden
via Lars Thunberg, SM0TGU
www.amsat.se
https://x.com/amsat_sm

If a company respond, these are the requirements that I will give them:

Most prioritized specifications – needed to make the radio possible to use:

  • Frequency bands involved for full duplex are VHF (144–146 MHz) and UHF (430–440 MHz). Both Analog FM
  • Extended filtering needed between VHF and UHF band with sharp and good filters (low-pass/high-pass or band-pass or a combination)
  • It should be possible to transmit on one band and at the same time receive on the other band without any desense (the transmitted signal cannot block the received signal).
    For example, transmit on VHF and at the same time listen on UHF. Or transmit on UHF and at the same time listen on VHF.
  • It should be possible to use both VFO and memory channels with full duplex. Or a combination between VFO and memory channel. For example, it should be possible to transmit on a VHF memory channel and receive with UHF VFO so the user is free to change the memory or VFO during a contact. In detail:
    • Possible to transmit on VHF memory channel and receive with UHF VFO
    • Possible to transmit on UHF memory channel and receive with VHF VFO
    • Possible to transmit with VHF VFO and receive on UHF memory channel
    • Possible to transmit with UHF VFO and receive on VHF memory channel
  • Possibility to transmit CTCSS (Subtone)
  • Connectors for Mic/Earphone so it should be possible to use a headset
  • Robust antenna connector. The handheld radio will probably be used in portable situations with an external handheld antenna (like the Arrow yagi) and will have a coaxial cable connected instead of the small supplied rubber antenna. So it is important that the antenna connector will not break easily.
  • USB-C charging with DC input for easy use of standard chargers for charging the battery or powering the handheld directly if the battery is drained
  • 5 watt max output with possibility to choose lower output
  • Implement energy saving functions so the battery will last longer. Or just make a good design for decent battery life.
  • All other standard features you already have implemented in your amateur radio handhelds, and make it easy to change the settings

Also wanted features – nice to have but not first priority:

  • APRS functions with GPS (look at the Kenwood handhelds)
  • Implement Bluetooth to be able to connect wireless headset
  • Implement computer connection via Bluetooth to be able to program the radio (memory channels etc.) via a computer or mobile phone app
  • Implement the CAT protocol via Bluetooth to simulate a COM port. If so, it would be possible to connect the handheld wirelessly to a computer, making it possible to adjust the frequency for the Doppler effect caused when the satellite is moving very fast in space. Many radio amateurs that are using satellites for communications use computer software for adjusting the VHF and UHF continuously during a contact. The CAT protocol is a standard and implemented in many amateur radio rigs, also by new manufacturers, and there is much software ready to use today.

What I know of today is that at least one manufacturer has implemented an app that can adjust frequency for Doppler correction, the VR-N76. Please see this link:
https://www.verotelecom.com/VR-N76-Dual-Band-Handheld-Radio-p2511333.html?parent_user_id=18403738&utm_source=sns_share&utm_medium=share_url

But this requires a lot of software development from you as manufacturer. A much better solution is to implement the CAT protocol so the user can choose software of their own.

Categories
Ham Satellite news

AO-123 FM Transponder to Enter Continuous Service

The FM transponder on AO-123 has been activated on periodic basis since its launch in late 2024. Beginning this weekend (Aug 2025), it is expected to enter continuous service if no issues are observed.

AO-123 (ASTRU-1) is a 12U Cubesat mission designed by Russian and Chinese university students for education and amateur radio. The amateur radio station provides telecommand uplink and telemetry / digital image downlink.

A new SDR based transceiver was developed for ASRTU-1 to provide communication and experiment resources to radio amateurs, including a V/U FM transponder, a UHF telemetry downlink and a 10.5G image downlink.

The uplink is 145.850 MHz with a 67 Hz CTCSS tone and the downlink is 435.400 MHz.

[ANS thanks the AO-123 team for the above information]