RTL-SDR & FUNcube

While World Cup was continuing its exciting show, I made some my RTL-SDR and satellite research progress. My next target was FUNCube Sat (aka) FUNcube-1 (AO73) is a complete educational single CubeSat project with the goal of enthusing and educating young people about radio, space, physics etc.

Introduction

FUNcube-1 (AO-73) Satellite

There is one thing that Funcube is magnificent than others, it’s data warehouse. The earth station can receive its telemetry data and can upload this data to data warehouse by online. There is also Dashboard Application for telemetry data decoding and uploading to data warehouse.

Here is the link for those who interested.

– Funcube Handbook 

– Data Warehouse

Dsahboard Application

N4JTC wrote about RTL-SDR and Funcube  , I followed this.

http://n4jtc.wordpress.com/2013/11/23/rtl-sdr-sdr-radio-funcube-sat-fun/

This time SDR Radio V2 software was used because this software has some distinct features such as sat tracking and I liked to test it. I believe that any rtl-sdr app can do this.

 http://v2.sdr-radio.com/Download.aspx

 

OK, before world cup final match, I do this. I tuned 145.9xx MHz and saw waterfall data stream and audible beep. It is SSB data.

funcube_manualtuning

Then, piped audio data stream to Dashboard application. The telemetry data show up.

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I already registered to Data-warehouse sites and Dashboard App automatically uploaded to warehouse site. Then, my uploaded data appeared in site. Seem I am the only one and first data provider earth station from Myanmar.

 

funcube_datawarehouse2

# Final thought

– Noticed some noises along with the whole spectrum and some recommend for shielding. I have to test it. Anyway, shielding an RF device is a best practice. Hree is the link for this. I will try this.

http://sdrformariners.blogspot.com/2013/09/reducing-electrical-noise.html

Anyway, it is happy research and hobby time.

okelectronic.wordpress.com

 

 

 

 

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RTL-SDR Second Attempt

After leaving my RTL-SDR for one year, last month, I had a chance to test it again. Yes, last month , World Cup 2014 began on June and ended on July. How World Cup was related to RTL-SDR testing? Due to the east and west time zone differences, local time for match schedule in my country (Myanmar) is beyond midnight. It was a chance to make, test something while waiting for the matches.

I remember an article about tracking hobby, educational satellites with rtl-sdr. Goggled and found out these articles, good to go.

Tracking NOAA Weather Satellite with RTL-SDR,

http://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weather-satellite-images/

Then, checked when NOAA sats will passed my location from these satellite tracking websites.

http://www.n2yo.com/

http://www.satview.org/

Checked that active sats regularly pass my location before midnight. Great, that is how I my rtl-sdr was related to world cup :D.

I read article and follow instructions thoroughly. Installed required software,

  • SDR# for receiving Sats
  • VB-cable for audio piping from rtl-sdr to sound card
  • Orbiton  for tracking satellites
  •  WXtoImg for decoding the APT signal

Most of rtl dongles have more or less tuning freq error. After finished installation of all software, I calibrated freq ppm error with these instruction. It is sample, monitored local GSM freq band and  adjusted error.

http://rtl-sdr.sceners.org/?p=193

1# Antenna

What I need was an external antenna for 137~145 MHz reception. I built Ground Plane antenna in an evening because this is easy to build.

Each antenna element = 51 cm, used old N type RG213 male connectors for assembly.

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Finished and installed antenna.

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After tuning and trials, I track and tuned NOAA-15 satellite signal successfully.

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But the decoded image was noisy and not good.

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2# Second Antenna (QHF)

After several attempts, I realized that a good antenna was required for better reception. So, I tried to build second DIY antenna. After a few research, I chose Quadrifilar Helix (QFH) antenna type.

Design calculation can be done here.

http://jcoppens.com/ant/qfh/calc.en.php

And here is ready made design by G0HPO.

 

First , collected required copper wire (12 gauge, enamel), female RG213 connectors, coax-cable , wood rod etc. Then, tried to bend, loop copper wire for helical shape.

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Soldered feed point with the help of small PCB.

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Loop the balun and connector.

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Final assembly, also attached recycled  rain drop covers for feed and connector 😀

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Hoisted the antenna, ready to go.

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As expected, second attempt results ware not so bad. The receiver show more stronger signal than first antenna.

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There are still noises in receptions when sat is at lower azimuth.

Some results,

2014-07-11_175443

2014-07-11_175323

 

# Results

– QHF antenna is better reception than Ground plane

– BUT, QHF is a lot noisy than Ground plane

– Do I need parabolic or YaGi with tracking ?? for next

# Final thought

Sure, I need LNA for next and future test. Need to find out the list for DIYable LNA.

http://www.rtl-sdr.com/tag/low-noise-amplifier/

http://blog.kf7lze.net/2012/09/14/round-up-of-rtlsdr-upconverter-choices/

 

Fun midnight modern hamming while waiting for World Cup.

 

https://okelectronic.wordpress.com

 

 

RTL-SDR First Experience

Last year, I heard about cheap SDR using DVB-T USB stick. Like everybody else, I quickly found and bought one of these RTL chip base dongle from local supplier.  My dongle is this one. It is ezcap DVB-T stick, model EXTV668 ver 8.0. This stick work well with most RTL-SDR software. I tested it with SDR#, HDSDR, SDR-RADIO.COM V2.

After testing some program and tuning local FM stations, I leaved this dongle for year.

List of compatible software is here,

http://www.rtl-sdr.com/big-list-rtl-sdr-supported-software/

Most helpful resource and credited sites are;

http://www.rtl-sdr.com/

http://rtlsdr.org/

Quick start guide,

http://www.rtl-sdr.com/rtl-sdr-quick-start-guide/

 

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Listening Mandalay FM 88.9 MHz…loud and clear, you’re 59 ….

88.9FM