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Support AMSAT When You Shop at Amazon.com

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amazon-logo._V192256676_AMSAT-NA is participating in the AmazonSmile program. AmazonSmile is a simple and automatic way for you to support your favorite charitable organization every time you shop at Amazon.com, at no cost to you.

Amazon will donate 0.5% of eligible AmazonSmile purchases to the charitable organization of your choice. If you do business with Amazon you can apply your donation by logging into your Amazon account using http://smile.amazon.com/ch/52-0888529 to designate AMSAT-NA as the organization of your choice. When shopping on-line you must use the URL smile.amazon.com for AMSAT to receive the donation from your purchases.

DELFI-N3XT update

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delfi-n3xtThe following update was provided today on the DELFI-N3XT satellite launched in November 2013:

Dear radio amateurs,

It has been a while since we have provided an update, so it is time to brief you again.

Delfi-n3Xt Status

The satellite is doing fine and is in healthy shape. We are now almost 3 months in orbit and have fulfilled a major part of the primary mission objectives. This means that we are close to a mission success. This does not mean that everything works flawlessly as there are several subsystems with issues. Given the amount of payloads and new technologies, I can only say that this was to be expected and accounted for in the mission. Delfi satellites are developing platforms and Delfi-n3Xt is an in-orbit test facility. The good thing is that issues encountered are not even a final verdict on the subsystems performance. The attitude determination and control subsystem currently is hampered by a high magnetic noise, but might still be tweaked and tune to see if we can get it to work properly. This however takes some time, so we are glad that the satellite seems to be in healthy state and we can take more time to experiment with it.

DUDe

We are still working on an improved version of DUDe to tackle several issues which we and many of you have discovered and reported. Unfortunately, many of these issues are more difficult to tackle than anticipated and will still take a while before we can release a new solid version of DUDe. One of the main issues is the fact that the software freezes after receiving noise for some time, meaning that DUDe needs to be restarted each time. Attached is a version of DUDe with a dirty fix which resets the PLL every minute. The penalty is that a 1 or 2 frames are lost each minute, so the performance is less than version 5.1. It is however much more convenient for automated ground stations (like our own) and therefore we decided to release this version.

Transponder

We are going to test the transponder functionality of Delfi-n3Xt this week. I have to be honest that this functionality was implemented last minute on the satellite and was only tested briefly in a non-representative setup. I therefore estimate the chance that it will work at 50/50.

Our first test series will be:

Thursday 20-02-2014 at about 10:50 UTC

Friday 21-02-2014 at about 9:50 UTC

Friday 21-02-2014 at about 11:25 UTC

After a few initial tests, and provided that it works, you are free to use the transponder for communication. We will leave it in this mode for the remainder of the sunlit part of the orbit, so only in Europe and Africa it is possible to use this mode for now. If successful we will turn on the transponder more often and for longer periods of time such that everyone can enjoy it.

(Editor’s note : Downlink 145.880 -145.920MHz, Uplink 435.530-435.570MHz, Telemetry on 145.870MHz and 145.930MHz and a high speed downlink on 2405.00MHz)

S-band Transmitter

There seems to be a problem on the S-band transmitter causing the current protection to kick in occasionally. Maybe this is due to charging or some other effect, as the board is not protected by The Onboard Computer leaves the transmitter off after several attempts as part of an internal safety mechanism. We can still turn on the S-band transmitter through telecommand, but this will only last for a few passes. Most cases the S-band transmitter will thus be off and it reporting that we have turned it might not be very effective since it might be off again by the time you read the message. If you are still interested to try and receive the beacon signal of the S-band, please check the regular telemetry in DUDe under ‘Status’à’Satellite Status’à ‘Subsystem Status STX’ to see if it is actually on.

J. (Jasper) Bouwmeester, MSc.

Delfi Nanosatellite Program Manager &

Researcher Small Satellite Technology

Chair of Space Systems Engineering

Delft University of Technology

University of Louisiana CAPE II Cubesat Designated LO-75

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cape-2OSCAR Number Administrator Bill Tynan, W3XO announced the University of Louisiana’s CAPE II cubesat has been designated as University of Louisiana OSCAR 75 or LO-75.

Bill wrote to AMSAT mentor Nick Pugh, K5QXJ, and the CAPE II cubesat team, “I have been able to determine CAPE II has met all of the
requirements for an OSCAR number. By the authority vested in me by the AMSAT-NA president, I hereby issue CAPE II the designation University of Louisiana OSCAR 75 or LO-75. I, and all of the amateur satellite community, wish LO-75 the best of success”.

CAPE II operates on 145.825 MHz with a CW beacon with the callsign W5UL, it also includes a digipeater, text to speech operation, a simplex repeater, email and tweet functions. The ground station software can be downloaded from http://www.ulcape.org

FunCube-1 was recently issued OSCAR designation as AO-73. CubeBug-2 was designated as LO-74.

Update on HamTV on ISS

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This was posted earlier today to amsat-bb by Gaston Bertels, ON4WF, ARISS-Europe chairman:

HamTV Bulletin #5
January 26, 2014

Ham Video Commissioning– Blank Transmissions

As announced December 22, 2013 the Ham Video transmitter is onboard the International Space Station and stored in the Columbus module. It is slated to be installed February 5, 2014 by Michael Hopkins KF5LJG. Hopkins will also install the camera and the supporting Bogen arm.The Ham Video transmitter will be connected to the ARISS 41 antenna and to the KuPS power supply. The installation procedure comprizes a check of the electrical connections. The transmitter will be powered on and will transmit a signal on 2.422 GHz. This check will be very limited in time, just enough to verify that the control LEDs are nominal. Then Ham Video will be powered off, ready for the first Commissioning Step.
January 23 and 24, Commissioning Simulations were again performed by ESA, in collaboration with ARISS. The ARISS Team, in charge of receiving the signals during the Commissioning, worked with B.USOC, simulating the four scheduled Commissioning Steps. The procedure was an update of the Simulations performed 5-6 September 2013,
as reported in HamTV Bulletin #2. (All HamTV Bulletins are archived at <http://www.ariss-eu.org/>www.ariss-eu.org ).The four Commissioning steps are scheduled February 8, 15 and 16 and March 5. These dates are still to be confirmed and this depends on the
signature of the Flight Rules relative to Ham Video (see HamTV Bulletin #4). Blank Transmissions will start immediately at the conclusion of Commissioning Step 1 and will
continue till Commissioning Step 4. This means that the Ham Video transmitter will operate continuously during 25 days.

The DATV signal parameters will be:
* Downlink frequency: 2.395 GHz
* DVB-S standard (QPSK modulation)
* Symbol rate: 1.3 Ms/s
* FEC : ½
* Video PID = 256
* Audio PID = 257
* RF radiated power : approximately 10 W EIRP
Ham Video will operate with a Canon XF-305 camera, but the camera will be turned off during the Blank Transmissions.

Blank Transmissions
A « blank » DVB-S signal contains all the data of normal DVB-S. The information tables describing the content and the content itself, i.e. the video (black) and the audio (silence), are the same as for the image and the sound produced by a camera.Receiving a black image and silent sound may seem uninteresting but, from a technical perspective,
the digital signal offers an important source of information.

The decoded signal provides many data :
* the video stream can be measured (Tutioune + TS reader)
* the audio stream can be measured (Tutioune + TS reader)
* the DVB tables can be decoded (satellite receiver (Set Top Box) or Tutioune or TS reader or VLC …)
The DVB tables mention the PIDs (content identification numbers) as well as the SDT
(Service Description Table) with the TV channel name, which will be « HAMTV »
Even without decoding, several measurements of the received signal provide valuable information:
* analogic HF signal strength  (dBm)
* analogic Signal/Noise ratio (dB)
* digital Signal/Noise ratio = MER (dB)
* error/correction ratio = Vber, Cber …
* validation of the received transport stream = TS

Reception Reports
Ground stations with S-band capability can provide valuable information, which will be much appreciated.Basic data such as:
* noise level without signal
* AOS and LOS time (UTC)
* maximum signal level during pass
can be reported by ground stations without the need of special DATV hard- and software.
ARISS is preparing a Ham Video Internet Reporting Program for collecting reception data from volunteering ground stations.These most needed reception reports will be gratefully accepted.

Basic DATV receiver
A “Set Top Box” or a Television receiver with satellite tuner can be used for receiving Ham
Video signals during a pass of the ISS.

Bill Ress, N6GHZ has provided an excellent article, Low Cost DVB-S Receivers Suitable For HAMTV Reception, in the November/December issue of the AMSAT Journal.  While normally only available to our members, AMSAT-NA is pleased to make it available in our Sample Download Section.

When scanning the 2.395 GHz frequency, the DVB stream can be decoded. When this is successful, the channel name « HAMTV » will appear on the TV screen.

Windows computer with TechnoTrend TT S2-1600 card and Tutioune software

A Windows computer with TT S2-1600 receiver card can be used for Ham Video reception. See appended Block Diagram of N6IZW Station.

The Tutioune software, developed by Jean Pierre Courjaud F6DZP, measures and  records  the Ham Video signals second per second:
* HF signal level
* digital Signal/Noise level = MER (dB)
* error/correction = Vber
·         validation of the received transport stream = TS

The recorded file can be examined and forwarded to ARISS.

Better even, the data can be forwarded during an ISS pass to the TiouneMonitor on
the   http://www.vivadatv.org/>www.vivadatv.org website. In other words, the data can be observed worldwide, real time.

Tutioune also shows the constellations during signal reception (see HamTV Bulletin #4). The TS stream can be recorded, but this is less interesting since richer information is already available.

Tutioune also decodes the DVB tables and provides the PIDs and the channel name  (« HAMTV ») recovered from the SDT table.

73,

Gaston Bertels, ON4WF
ARISS-Europe chairman

Annex:
www.ariss-eu.org/N6IZW_Station.pdf