Caution Urged in Using High Duty Cycle Digital Modes via Satellite

Amateur Radio Satellite FO-29

Amateur Radio Satellite FO-29

A report in ANS-288 discussed an experiment operating with the WSJT-X FT8 digital mode via satellite. Satellite operators have gained more experience with this mode over this past week.

As a result of on-the-air observation other satellite users planning to try FT8 or MSK144 modes via satellite are encouraged use caution using these modes and possibly avoid their use completely in light of problems.

Dave, KG5CCI wrote, “He noticed a very hard time getting into the transponder. The pass was nearly overhead, and the 3w-4w that is normally sufficient was barely cutting it. I also noticed it was ‘up and down’ alot, whereas some moments it was easy to get in, then it would be nearly impossible. There were also pockets of ‘noise’ all over the transponder, that sounded somewhat digital, but I just couldn’t place them.” Further investigation revealed that an MSK144 signal in the transponder passband was causing the problems.

Matthew, NJ4Y noted, “Experimentation isn’t the problem, too much power is. It’s bad enough on SSB, worse with CW, and killer on constant duty cycle modes like FT8.”

To gain a full understanding of the situation readers are encouraged to follow the amsat-bb message thread which can be accessed at http://www.amsat.org/pipermail/amsat-bb/2017-October/064896.html

Source: AMSAT News Service http://www.amsat.org/mailman/listinfo/ans

CAS-4A and CAS-4B amateur radio linear transponders activated

CAS-4A and CAS-4B launch on CZ-4B

CAS-4A and CAS-4B launch on CZ-4B

On Wednesday, October 18, 2017 the amateur radio linear (SSB/CW) transponders on the CAS-4A and CAS-4B satellites were activated.

CAMSAT’s amateur radio payloads piggybacked on the optical remote sensing micro-satellites ZHUHAI-1 01 (OVS-1A / CAS-4A) and ZHUHAI-1 02 (OVS-1B / CAS-4B) that were launched at 0300 GMT on Thursday, June 15, 2017 from the Jiuquan Satellite Launch Center, on the CZ-4B launch vehicle. The primary payload of the launch was a hard X-ray modulation telescope satellite (HXMT).

Satellite CAS-4A/OVS-1A/ZHUHAI-1 01:
● Architecture: Micro-satellite
● Dimensions: 494Lx499Wx630H mm
● Mass: 55 kg
● Stabilization: three-axis stabilization system with its +Y surface facing the earth
● Primary Payload: optical Camera with 1.98m resolution

CAS-4A Orbit:
● Orbit type : Sun synchronization orbit
● Apogee: 524 km
● Inclination: 43°
● Period: 95.1 minutes

CAS-4A Amateur Radio Payload:
● Call sign: BJ1SK
● VHF Antenna: one 1/4λ monopole antenna with max. 0 dBi gain located at +Z side
● UHF Antenna: one 1/4λ monopole antenna with max. 0 dBi gain located at -Z side
● CW Telemetry Beacon: 145.855 MHz 17 dBm
● AX.25 4.8k Baud GMSK Telemetry: 145.835 MHz 20 dBm
● U/V Linear Transponder Downlink: 145.870 MHz 20 dBm, 20 kHz bandwidth, Inverted
● U/V Linear Transponder Uplink: 435.220 MHz

CAS-4 Satellite

CAS-4 Satellite

Satellite Name: CAS-4B/OVS-1B/ZHUHAI-1 02:
● Architecture: Micro-satellite
● Dimensions: 494Lx499Wx630H mm
● Mass: 55 kg
● Stabilization: three-axis stabilization system with its +Y surface facing the earth
● Primary Payload: optical Camera with 1.98m resolution

CAS-4B Orbit:
● Orbit type : Sun synchronization orbit
● Apogee: 524 km
● Inclination: 43°
● Period: 95.1 minutes

CAS-4B Amateur Radio Payload:
● Call sign: BJ1SL
● VHF Antenna: one 1/4λ monopole antenna with max. 0 dBi gain located at +Z side
● UHF Antenna: one 1/4λ monopole antenna with max. 0 dBi gain located at -Z side
● CW Telemetry Beacon: 145.910 MHz 17 dBm
● AX.25 4.8k Baud GMSK Telemetry: 145.890 MHz 20 dBm
● U/V Linear Transponder Downlink: 145.925 MHz 20 dBm, 20 kHz bandwidth, Inverted
● U/V Linear Transponder Uplink: 435.280 MHz

73!
Alan Kung, BA1DU

CAMSAT Press Release PDF

N2YO online real-time tracking:
CAS-4A http://www.n2yo.com/satellite/?s=42761
CAS-4B http://www.n2yo.com/satellite/?s=42759

CAS-4A and CAS-4B

AMSAT-UK Colloquium Talks – Videos being added to YouTube

Working satellites with Arrow AntennasVideos of the presentations given at the AMSAT-UK International Space Colloquium, which was held as part of the RSGB Convention in Milton Keynes, October 14-15, are being made available on YouTube.

The first of the videos is ‘An introduction to Amateur satellites’ by David Johnson G4DPZ and Carlos Eavis G3VHF.

The PDF of the slides is here.

Other presentations are expected to be uploaded in the coming days.

Watch An introduction to Amateur satellites

PDF Slides of ‘An introduction to Amateur satellites’
https://ukamsat.files.wordpress.com/2017/10/beginners-guide-to-amateur-satellites-by-dave-johnson-g4dpz.pdf

AMSAT-UK videos on YouTube https://www.youtube.com/user/AMSATUK/videos

Our thanks to the British Amateur Television Club and Wouter Weggelaar PA3WEG for their work in recording, editing and uploading these videos.

Live streaming of talks from International Space Colloquium Milton Keynes

Kents Hill Park Conference Centre Milton Keynes MK7 6BZ

Kents Hill Park Conference Centre Milton Keynes MK7 6BZ

Thanks to volunteers from the British Amateur Television Club (BATC) the presentations given at the AMSAT-UK International Space Colloquium will be streamed live to a global audience.

This year the Colloquium is taking place as part of the RSGB Convention at the Kents Hill Park Conference Centre, Timbold Drive, Milton Keynes, MK7 6BZ on the weekend of October 14-15.

The webstream of the Colloquium talks will be available at https://beta.batc.tv/live/amsatuk
(The other talks at the RSGB Convention are not being streamed)

The Live Stream will begin on Saturday morning, October 14 at 9:30am BST (0830 GMT) with the presentation ‘Everything you wanted to know about Amateur Radio on the International Space Station (ARISS)’ by ARISS Contact Coordinator Kenneth Ransom N5VHO.

The AMSAT-UK Colloquium is talking place in Lecture Room 5 download the programme schedule from
http://rsgb.org/main/about-us/rsgb-convention/rsgb-convention-programme/

Tickets to the event are available at the door or you can book in advance at
http://rsgb.org/main/about-us/rsgb-convention/

Recordings of all talks will be posted on the AMSAT-UK YouTube Channel after the event
https://www.youtube.com/user/AMSATUK

British Amateur Television Club http://www.batc.org.uk/

Geostationary Amateur Radio Transponder Talk and Demonstration

Coverage area of Es'hail 2

Coverage area of Es’hail 2

On Saturday, October 14 at 1:45pm BST (1245 GMT) AMSAT-DL President Peter Guelzow DB2OS will give a presentation on the Es’hail-2 Geostationary Satellite Amateur Radio Transponders to the AMSAT-UK International Space Colloquium in Milton Keynes.

It is expected the presentation will include a demonstration of the P4A transponder simulator. All attendees are welcome to bring any equipment they have for CW/SSB or DATV for the 2.4 GHz and 10.5 GHz bands. The transponder mimics the real thing: 2400-2410 MHz uplink to 10489.5-10499.5 MHz downlink.

This year the AMSAT-UK Colloquium is taking place as part of the RSGB Convention at the Kents Hill Park Conference Centre, Timbold Drive, Milton Keynes, MK7 6BZ on the weekend of October 14-15. Tickets to the event are available at the door or you can book in advance at
http://rsgb.org/main/about-us/rsgb-convention/

The Colloquium is talking place in Lecture Room 5, download the programme schedule from
http://rsgb.org/main/about-us/rsgb-convention/rsgb-convention-programme/

Live streaming of Colloquium talks https://amsat-uk.org/2017/10/11/live-streaming-space-colloquium-mk/

New ham radio equipment for ISS

ARISS 25 watt JVC Kenwood D710GA at Hamvention 2017 - Credit John Brier KG4AKV

ARISS 25 watt JVC-Kenwood D710GA at Hamvention 2017 – Credit John Brier KG4AKV

The ARISS website reports on progress towards flying new amateur radio equipment to the International Space Station.

On behalf of the ARISS International team, I am proud to announce that on Friday September 29th the ARISS team submitted the InterOperable Radio System (IORS) Safety Data Package to NASA for review!  Our next step in this process is the Safety Review, which is planned for November 2.

Submitting this was a phenomenal accomplishment!!  Particularly since the entire Safety Data Package was developed exclusively by our ARISS volunteers—something we have never done before.  Prior to this submittal, all safety packages—from Owen Garriott’s in the early 1980s to today–were developed with contractors from NASA, ESA or Energia.  And might I say at substantial expense.  I am pleased that the ARISS team did it ourselves!

International Space Station – Image Credit NASA

Why is this important?  Two reasons:

1) This is a very major IORS milestone. We cannot get to orbit without successfully completing the safety review process and getting our hardware certified for flight.
2) Developing the safety package exclusively with volunteers is an innovative and gutsy approach to keep costs down and get the hardware flown sooner.  Otherwise we probably would have to slip launch 1-2 years while we acquired additional funding to get this done.

NASA Human Spaceflight Safety Certification is a four-step process—Phase 0, Phase 1, Phase 2 and Phase 3.  The material we submitted covers the first three of the four phases.  As part of Phases 0, 1 and 2, we need to make sure NASA understands our design.  And we need to show NASA that we understand all the potential hazards that our hardware systems could introduce to ISS and how we have mitigated (or prevented) these hazards.  One example is to demonstrate to NASA that our IORS was designed with electrical wiring and circuit breakers that possess adequate features and sufficient margin to prevent an electrical shock or fire on-board the ISS.  Critically important stuff!  The final phase (Phase 3) will be complete when we have completed all testing and NASA inspection of our flight hardware and NASA deems it flight worthy.  At that point the IORS will be flight certificated and we can fly!  Currently we are looking to March-May 2018 for flight readiness.

For those not following ARISS hardware development very closely, we are developing the IORS to replace most of the on-board radio hardware. It is called “interoperable” because it is being designed to be operated anywhere on ISS.  But specifically, it will be used in the two areas with ISS Ham legacy antennas: the Columbus Module and the Russian Service Module. Interoperability allows us to leverage existing ISS power cables, it can be moved between modules in the event of on-orbit failures, and it supports common training and operations.

Multi-Voltage Power Supply with JVC-Kenwood D710GA on mounting bracket

The IORS is the most complex in-cabin hardware system we have ever designed, built, tested and flown as a volunteer team. We will remove the 3 watt Ericsson handheld radio system, initially certified for flight in 1999, and the Packet module–both of which have recently had issues—and install a brand-new, specially modified 25 watt JVC Kenwood D710GA radio to enable a multitude of new or improved capabilities on ISS, including voice repeater and better APRS operations.  A key development is the Multi-Voltage Power Supply (MVPS), which interfaces with multiple electric outlet connection types on ISS and provides a multitude of power output capabilities for our current and future ARISS operations and amateur radio experimentation.  It will also allow our Ham Video system to have a dedicated power outlet, eliminating the outlet sharing we have now, which shuts down Ham Video at times.

This effort would not be possible without the dedication and persistence of our IORS development team of volunteers.  They have been working tirelessly behind the scenes to provide an outstanding amateur radio experience for all.  Our IORS development team includes: Lou McFadin, W5DID, our Chief Engineer; Kerry Banke, N6IZW, the MVPS lead designer; Bob Davis, KF4KSS, the MVPS Mechanical enclosure designer; Ed Krome, K9EK, supporting IORS thermal control and cabin noise dissipation; Dave Taylor, W8AAS, our JVC Kenwood D-710 development liaison; Bob Bruninga, WB4APR, our APRS and D-710 operations expert; Shin Aota, JL1IBD, and Phil Parton, N4DRO for all their phenomenal support from JVC Kenwood; Kenneth Ransom, N5VHO, our operations lead; and our safety package team—Ken Ernandes, N2WWD, and Gordon Scannell, KD8COJ.  Kudos to all on a fantastic effort!

Designing, building and testing the IORS is a huge undertaking and *very* expensive.  We need to build ten (10!) units to support flight hardware, flight spares, testing, and training across the international team.  Hardware parts, development tools, fabrication, testing, and expenses to certify the IORS are expected to cost approximately $150,000.  And the hard part (i.e. most expensive part) is just now starting.  So please consider making a donation to ARISS to take our hardware system from dream to reality.  You can donate to ARISS directly through the AMSAT web site at:  http://www.ariss.org/donate.html.  ALL donations go directly to ARISS.

Thank you for all your support to inspire, engage and educate our youth to consider wireless communications and amateur radio, and to pursue STEAM careers through our exciting human space exploration and amateur radio endeavor!

Ad Astra!  To the Stars!

Sincerely,
Frank H. Bauer, KA3HDO
ARISS International Chair and ISS Ham Radio Principal Investigator

Source http://ariss.org/