Circuit for Farhan's Satellite -- Arduino in SPACE

Farhan sent me the schematic of the AISAT amateur digital satellite that went into orbit on April 1, 2019 from India.   He notes that the circuitry is very simple.   Indeed, it reminds me of the very simple but effective circuitry we saw in satellites in the early days of the space age.  Beautiful simplicity, with an Arduino on-board.   And it is great to see that Farhan did not forget the low pass filter.  FB OM.  

Packets from Farhan's Space Ship

Farhan's AISAT flew over this morning.   Using HD-SDR software, an RTL-SDR Dongle,  and my Dominican Republic refrig tubing quad I was able to capture some the packets.  Above you can see one of them, floating like a flying saucer in the waterfall.  Pretty amazing that that signal came from a machine put in space by our friend Farhan.  

Congratulations to Farhan on New Amateur Satellite Launched 1 April

This is not an April 1 trick.  Farhan and Exseed Sat have put another bird in orbit.  
Details here: 
http://amsatindia.org/

This site in Argentina gives pass information: 
http://amsat.org.ar/pass?satx=aisa1

I will be listening tonight! 

Congratulations Farhan! 

More info: 

https://www.isro.gov.in/launcher/pslv-c45-emisat-mission

https://makeinhyderabad.com/private-satellite-with-hyderabad-origin-aisat-starts-off-well/

Malicious Code in the Si5351 -- Pete quitting podcast

Those of you who have been reading Pete N6QW's blog (and all of you should be reading it!) will have seen a recent post about his efforts to modernize (digitize) the VFO in an old tube-type Ten Tec Triton IV model 544.  Pete complained that --oddly -- in spite of replacing the old analog tube-type VFO, the rig with a modern, rock-stable Si5351 VFO, the old rig CONTINUED TO DRIFT.  That had Pete and a number of us scratching our heads.  How could that be?  

Pete then completely removed the Si5351 VFO from the old boatanchor.   Sitting on his bench, all by itself, THE DAMN THING EXHIBITED ALL THE CHARACTERISTICS OF ANALOG VFO THERMAL DRIFT.  Wow!  Why?  Pete was really pulling his hair out on this one. 

We immediately began to see if others were getting the same results.  Nope.  None of our Si5351 VFOs were doing this.   This was REALLY strange.  

At this point we had to turn to a real Arduino expert, a guy who I had met during my time in Italy: Luigi Bugiardo from the Arduino research center in Bocalupo, Calabria.  Pete gave him remote access to his computer and he began to poke around.  

It didn't take long.  Luigi quickly found the problem:  He found several lines of malicious code "embedded in the Si5351.h and si5351.cpp files –sort of lurking out there and not easy to spot." 

Pete then removed this code and -- BINGO -- no more drift.   

Now I know some of you guys are thinking that this was just a bit of harmless fun.   But Pete is really angry about this.  He feels like he has been played for a sucker by some ham who was pretending to collaborate with him.  Pete sees this as yet another violation of the unwritten ham code of conduct.  To him this is another intrusion of computer/hacker noob hazing into the ham radio world.  And worst yet, he thinks this malicious code came to him because of this involvement in the podcast and his blog -- that participation resulted in the widespread exposure that got him into this mess.  

Pete is so upset that he has vowed to drop out of the podcast and shut down his blog. 

So come on fellows.  It is time to 'fess up.  If you did this, or if you think you know who did this, please send an e-mail to me at soldersmoke@yahoo.com   I think being able to pinpoint the prankster will help Pete deal with this whole thing, and hopefully get him back into the SolderSmoke...   

So Much Cool Stuff on Pete N6QW's Blog

There is so much tribal knowledge, so many good ideas.  Be sure to visit Pete's blog regularly.  

http://n6qw.blogspot.com/

He needs the meter from an SBE-33.  Somebody out there must have one.  

Check out his stepper motor antenna tuner video.  

And be sure to leave some comments or to send Pete an e-mail with feedback.  I live in fear that he will think no one is reading and then stop posting.  We can't let that happen!  

Apollo 11 -- The Documentary

My wife is a kind and tolerant person.  Proof of this is that she went with me to see the Apollo 11 documentary that we recently posted about.  

I think you have to be a geek and/or have The Knack to really like a 90 minute documentary with no audio other than Walter Cronkite's reporting and the recorded dialogue among the participants.   But of course, I loved it.  Amazing video, especially of the Saturn V.  

Bob Scott KD4EBM found this great interview with the film maker: 

Video:

https://www.tested.com/science/space/869951-apollo-11-still-untitled-adam-savage-project-31919/

Audio only (downloadable)

https://d2rormqr1qwzpz.cloudfront.net/podcast/stilluntitled_20190319.mp3

Amazing New Geostationary Amateur Satellite -- LISTEN ONLINE!

Wow, quite a step forward in the amateur satellite world.  Qatar and AMSAT-Germany have collaborated to put an amateur radio repeater in geostationary orbit.  That's pretty amazing.  Read more here: 

https://hackaday.com/2019/03/18/eshail-2-hams-get-their-first-geosynchronous-repeater/

Read about a group of Norwegian students working on a satellite station for this bird: 

https://www.la1k.no/2019/02/20/getting-ready-for-e%CC%B6s%CC%B6%CC%B6h%CC%B6a%CC%B6i%CC%B6l%CC%B62%CC%B6-qo-100-part-2-how-we-did-it/

And this is really fun:  LISTEN TO THE DOWNLINK LIVE VIA WEBSDR! 

We can't hear this thing from North America -- it is flying over the Congo.  But stations in its footprint are putting their receivers online -- you can listen to the 10 GHz downlink via WebSDR: 

UK WebSDR:   https://eshail.batc.org.uk/nb/

Brazil WebSDR:     http://appr.org.br:8902/