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Friday, November 30, 2018

Totally Absurd -- Farhan Being Questioned in a Police Station


I walked into the shack this morning hoping to read good news about the InSight landing and the impending launch of Farhan's satellite, but instead I found this message from Farhan in a police station.   This is really absurd and disheartening.   Someone (not Farhan!) altered the Indian flag and put it into an image of Farhan's CubeSat.  So with 24 hours to go before the launch, our friend Farhan finds himself in a police station. 

Stay strong Farhan!  You have a lot of support around the world.  

Sunday, November 25, 2018

Falcon 9 Cubesat Launch Now Set for Wednesday



It looks like the Falcon 9 with Farhan's CubeSat is not scheduled to launch this Wednesday between 1030 and 1100 West Coast time.  Above you can see a similar launch.  

https://www.sanluisobispo.com/news/local/article222135690.html

Saturday, November 24, 2018

Friday, November 23, 2018

The Max Valier Satellite Flies Over, Sending CW



I understand the launch of Farhan's CubeSat has been delayed a few days.  That's the way it works in the rocket launch biz --patience is required.  In the meantime, I've been practicing with my receive system.  Today at 1000 local the Max Valier satellite flew to my west.  It rose 78 degrees above my horizon to the W NW.  I left my three element quad pointed in that direction and waited for the satellite (which had been launched from India) to fly through its pattern.  

The CW beacon was quite strong, very visible and audible through my RTL-SDR dongle and HD-SDR software.  You can see it and hear it in the video above.  There is something quite charming about this very personal Morse message coming down from orbit and then passing through all that digital technology.   

More info on the satellite: 



"Max Valier Sat" is an amateur satellite built in cooperation by:
  • "Max Valier" High School in Bolzano/Bozen (Italy)
  • OHB System AG from Bremen (Germany)
  • Max Planck Institute for Extraterrestrial Physics from Garching (Germany)
Its main payload is an X-Ray telescope devised and made by MPE. Data generated by this detector will be transmitted, together with housekeeping data, over an amateur radio link with frequency 145.860 MHz.
A second payload is an amateur radio beacon transmitting a message in Continuous Wave. The beacon's frequency is 145.960 MHz
"Max Valier Satellite" was launched by the Indian Rocket PSLV-C38 on June 23, 2017 at 9:29 am IST (05:59 am CET) from Satish Dhawan Space Centre.
More tech details: 
Regarding the CW beacon: 


Beacon by Holger Eckardt DF2FQ:

  • Transmit frequency is 145,960 MHz (IARU and ITU coordinated).
  • Modulation is CW:
    • Duration of one dot is 114 ms.
    • Duration of one dash is 342 ms.
    • Interval between words is 1881 ms.
    • Interval between repetitions of the message is 6000 ms.
  • The beacon transmits Max Valier Sat's call sign and a greeting message.
  • Transmitting power is 500 mW.


And who was Max Valier?  Quite an interesting fellow: 
Max Valier in his Rocket Car in 1930

Saturday, November 17, 2018

From BITX to SpaceX: Falcon 9 To Launch Farhan's Cubesat on Monday (video)



  1. SpaceX will live-stream the launch as well on their YouTube stream. Also - this will be the first SpaceX booster to fly three times, and the first to launch from all three SpaceX pads.

    https://forum.nasaspaceflight.com/index.php?topic=46756.0
Special thanks to Dave Bamford for the BITX to SpaceX line! 

Friday, November 16, 2018

Launch Date Approaches for Farhan's Satellite


It looks like the launch date might have been moved up from 24 November to 19 November. 

Wednesday, November 14, 2018

W7ZOI: Direct Conversion Receivers -- Some Amateur Radio History


http://w7zoi.net/dcrx68.pdf

Farhan and Pete WB9FLW alerted me to this wonderful article by Wes Hayward, W7ZOI.  I guess my interest in DC receivers must have been noticed by the Google algorithm because I am bombarded by ads extolling the virtues of "Zero IF."   Hey Google -- I'm already a believer!  I was converted by W7ZOI's 1968 article in QST. And my belief in the technique has been greatly reinforced by his November 2018 50th anniversary article. 

There is so much good stuff in Wes's look-back piece.  The travails of trying to write for QST are presented very well.   And we learn that none-other-than Doug DeMaw himself is responsible for the use of the word "presence" in describing amateur radio audio.  

This article has inspired me to take a new look at the DC receiver I built last winter.  Mine needs some work. I think it is kind of deaf.   It could probably benefit from a diode ring  detector.   But it already has presence.   

http://w7zoi.net/dcrx68.pdf

Thanks Wes.  And thanks to Farhan and Pete for the heads up. 

Monday, November 12, 2018

Getting Ready for Farhan's Satellite (videos)



I've been getting ready for the November 24 launch of the CubeSat that Farhan and his friends in India built.  I started out with my trusty Drake 2-B and a Hamtronics 2-to-10 downconverter, but I quickly switched to an RTL-SDR dongle and HD-SDR software.   My 3 element quad antenna is visible in the first video.   So far, I am using the Armstrong method to turn the antenna. 

In that first video I keep saying that I am waiting for AO-71.   In fact is was AO-73, the "FunCube" from the UK.   I think it is similar in power and antenna configuration to Farhan's satellite, so I think we are almost ready for launch.

(Any ideas on what that mysterious pulsating sig in the satellite passband signal is in the first video?)     

Monday, November 5, 2018

Pete N6QW Rejuvenates the Atlas Twins with an Arduino and an Si5351



Pete Juliano N6QW has turned his attention to the Atlas Twins, a nice single conversion multiband rig. Pete has used an Arduino/Si5351 to replace the analog oscillators in the old Atlas.  This improves stability and allows for USB/LSB operation.  

Pete very graciously kept the old analog circuitry in the rig, allowing the Atlas to be returned to its pristine analog state at some time in the future. Pete also made some very kind comments about the surprising stability of the original  analog oscillator circuitry.  

Check out Pete' site for more details: 

http://n6qw.blogspot.com/2018/11/2018-year-of-ssb-transceivers.html

Saturday, November 3, 2018

Oliver Heaviside

Image result for Oliver Heaviside
In the last SolderSmoke podcast we took a look at some of the giants of radio.   Here is one fellow we missed:  Oliver Heaviside.  Hackaday has an interesting profile of him: 

https://hackaday.com/2018/10/30/oliver-heaviside-rags-to-recognition-to-madness/#more-330784

Like many of the giants we looked at, Oliver definitely had his problems, and didn't end well.  But he deserves a lot of respect and credit for his many innovations and discoveries.   I didn't know that he is the one responsible for those 88 mH coils in my junk box.  
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column