Tag Archives: PSAT

Jun 7 2015

OSCAR Numbers Assigned for BRICsat (NO-83) and PSAT (NO-84)

PSAT PSK31 Transponder received by Peter Goodhall 2E0SQL May 26, 2015

PSAT PSK31 Transponder received by Peter Goodhall 2E0SQL May 26, 2015

The following message has been sent by the OSCAR Number Administrator Bill Tynan W3XO to Bob Bruninga WB4APR and the team at the US Naval Academy.

You have requested OSCAR numbers for BRICsat and PSAT built by you and your associates at the U.S. Naval Academy.

From everything I can determine, these satellites meet all of the requirements for OSCAR designations.

Therefore, by the authority vested in me by the AMSAT-NA President, I hereby confer the designation, Naval Academy OSCAR 83 on BRICsat and Naval Academy OSCAR 84 on PSAT These designations can, of course, for convenience, be shortened to NO-83 and NO-84.

I, and the entire amateur satellite community, hope for successful missions for both NO-83 and NO-84 and congratulate you and the rest of the Naval Academy team who designed, built and tested these two OSCAR spacecraft.

73,
William A. (Bill) Tynan, W3XO
OSCAR Number Administrator

NO-84 PSAT, a student satellite project named in honor of USNA alum Bradford Parkinson, of GPS fame, contains an APRS transponder for relaying remote telemetry, sensor, and user data from remote users and Amateur Radio environmental experiments or other data sources back to Amateur Radio experimenters via a global network of Internet-linked ground stations.

PSAT is another APRS satelliite that can digipeat user packets just like the original PCSAT (NO44) and the packet system on the ISS. PSAT also supports the same digipeating alias of ARISS so that users do not have to change any parameters when using any of these three APRS transponders.

See http://www.aprs.org/psat.html

NO-83 BRICsat-P (Ballistic Reinforced Communication Satellite) is a low cost 1.5U CubeSat built by the US Naval Academy Satellite Lab in  collaboration with George Washington University, that will demonstrate on-orbit operation of a Micro-Cathode Arc Thruster (µCAT) electric propulsion system and carries an Amateur communication payload.

see http://space.skyrocket.de/doc_sdat/bricsat-p.htm

Frequencies
PSAT: 145.825 – 1200 baud AX.25 telemetry – digi off
PSAT PSK31-5: 435.350 FM down, 28.120 SSB PK31 uplink – Brno University
Transponder

BRICsat: 437.975 – 9600 baud telemetry evry 20s
BRICsat PSK31-6 – same as PSAT but PSK TLM on 375 Hz (PSAT on 315 Hz)

How to work the PSK31 satellites https://amsat-uk.org/beginners/how-to-work-psk31-satellites/

OSCAR Numbers Policy http://www.amsat.org/?page_id=2478
IARU Amateur Radio Satellite Frequency Coordination http://www.iaru.org/satellite.html

[thanks to ANS and Bill Tynan, W3XO for the above information]

May 26 2015

UK radio amateurs use PSK31 satellite transponder

PSAT PSK31 Transponder received by Peter Goodhall 2E0SQL May 26, 2015

PSAT PSK31 Transponder received by Peter Goodhall 2E0SQL May 26, 2015

After building a 28 MHz 1/4 Wave Ground Plane antenna to replace his dipole Peter Goodhall 2E0SQL was able to receive his 10 watt signal through the PSAT CubeSat PSK31 transponder for the first time on Tuesday, May 26.

Peter Martinez G3PLX posted a report to the RSGB Tech Yahoo Group reproduced here with permission:

Finally got my own signal back via PSAT just now and proved  that the uplink frequency control works. The PSAT uplink receiver is about 300 Hz low of 28120 kHz which means that when the satellite is heading straight towards me at +600 Hz Doppler, my transmitter needs to be 900 Hz low.

If I chose to place my own signal on a downlink frequency of 1000 Hz, the transmit audio tone would have to be down at 100 Hz which is too low for my SSB transmitter. So I have chosen 1500 Hz in the downlink.

I will try again on the next few passes. I am just sending “Test de G3PLX via PSAT” continuously at the moment and not listening for replies.  Still not getting a strong downlink SNR so the power control loop isn’t kicking in.

Bob Bruninga WB4APR has made a request to developers of PSK31 software to open their PSK31 frequency tracking to accommodate more than 1 Hz per second Doppler shift. Current implementations can do 1 Hz/s but completely fail at 3 Hz/s.

PSK31 Transponder Frequencies:
PSAT: 145.825 MHz FM 1200 baud AX.25 telemetry – digipeater currently off
PSAT PSK31: 435.350 MHz FM downlink, 28.120 MHz SSB PSK31 uplink. W3ADO-5 PSK TLM beacon on 315 Hz

BRICsat: 437.975 MHz 9600 baud telemetry every 20s
BRICsat PSK31 435.350 MHz FM downlink, 28.120 MHz SSB PSK31 uplink. W3ADO-6 PSK TLM beacon on 375 Hz

Guide to using the PSK31 transponder https://amsat-uk.org/beginners/how-to-work-psk31-satellites/

ParkinsonSAT (PSAT) http://www.aprs.org/psat.html

Fldigi PSK31 software http://www.w1hkj.com/Fldigi.html

Keplerian Two Line Elements (TLEs) ‘Keps’ for satellites launched in last 30 days
http://celestrak.com/NORAD/elements/tle-new.txt

Adding new satellites to SatPC32 and Gpredict
https://amsat-uk.org/2013/11/23/adding-new-satellites-to-satpc32/

Listen to satellite signals in the 145 and 435-438 MHz bands from anywhere in the world using the online SUWS WebSDR located near London. Further details at https://amsat-uk.org/2014/08/15/suws-websdr-moves-to-new-site/

AMSAT-UK
Web https://amsat-uk.org/
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Facebook https://facebook.com/AmsatUK
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Yahoo Group http://groups.yahoo.com/group/FUNcube

May 24 2015

PSAT PSK31 CubeSat Update May 24

PSAT PSK31 FM Downlink received by Martin G8JNJ at 1429 UT May 22, 2015 using the online SUWS WebSDR

PSAT PSK31 FM Downlink received by Martin G8JNJ at 1429 UT May 22, 2015 using the online SUWS WebSDR

Bob Bruninga WB4APR released this update on the PSAT PSK31 CubeSat on Sunday, May 24

28 MHz PSK31 Receiver Board Flight Prototype - Brno University of Technology

28 MHz PSK31 Receiver Board Flight Prototype – Brno University of Technology

The PSAT PSK31 435.350 MHz FM downlink is full quieting with 6 bars using a decent UHF Yagi. But we have not seen any users other than those using the 28.120 PSK channel on HF normally. We welcome people to experiment with it.

Everyone within the 28.120 to 28.123 MHz ten meter passband will be uplinked and heard on the 435.350 MHz downlink.

The Naval Academy’s PSAT seems healthy with plenty of power (we are keeping the APRS digipeater off to allow max power for PSK31).

PSAT’s radio and packet system are a simple $250 APRS tracker http://www.byonics.com/mtt4b sent to space. The PSK31 transponder is a single 3.4″ square circuit board made by Brno Universtiy in the Czech Republic. The CPU for controlling bulletins and timing is a simple Parallax Basic Stamp.

PSAT is actually only about a 1U cubesat but in a 1.5U package since the flight was available and it gave us more power for our NON-SPACE solar cells. We are using standard silicon that are only half as efficient as multi-junction cells, but only cost 1% as much.

PSAT has a single 21″ VHF  and 72″ long HF whip. It has two UHF 6″ orthogonal monopoles, all of very thin Nitinol wire.

More details will eventually follow as the page will be updated over the coming weeks http://aprs.org/psat.html

* PSAT packet telemetry is OK, Digipeater will be off (secondary mission)
* PSAT PSK31 transponder is ON with 28.120 MHz uplink! (primary mission)
* WOD data fixed.  Spin data now available.  Right now it is at 3 RPM with
+Z pointing 45 deg off Sun
* Launch TLE elements (below) are still very good
* http://PCSAT.APRS.ORG web page is now capturing PSAT telelmetry that
users inject into the APRS-IS
* BRICSAT telemetry has been heard but is cycling OFF due to low power
* BRICSAT PSK31 downlink (also FM) has also been heard barely (when ON)
* USS Langley not heard

Frequencies:

PSAT: 145.825 – 1200 baud AX.25 telemetry – digi off
PSAT PSK31-5: 435.350 FM down, 28.120 SSB PK31 uplink – Brno University Transponder

BRICsat: 437.975 – 9600 baud telemetry evry 20s
BRICsat PSK31-6 – same as PSAT but PSK TLM on 375 Hz (PSAT on 315 Hz)

USS Langley – 437.475  9600 baud telemetry  <== CORRECTION

ULTRASat3  
1 99993U          15140.67013889  .00040043  00000-0  10235-2 0 00009
2 99993 055.0004 339.9238 0251027 182.3314 074.3075 15.12517086000014

Bob, WB4APR

Guide to using the PSK31 transponder https://amsat-uk.org/beginners/how-to-work-psk31-satellites/

ParkinsonSAT (PSAT) http://www.aprs.org/psat.html

Fldigi PSK31 software http://www.w1hkj.com/Fldigi.html

Listen to satellite signals in the 145 and 435-438 MHz bands from anywhere in the world using the online SUWS WebSDR located near London. Further details at https://amsat-uk.org/2014/08/15/suws-websdr-moves-to-new-site/

AMSAT-UK
Web https://amsat-uk.org/
Twitter https://twitter.com/AmsatUK
Facebook https://facebook.com/AmsatUK
Flickr https://flickr.com/groups/AmsatUK
YouTube https://youtube.com/AmsatUK
Yahoo Group http://groups.yahoo.com/group/FUNcube