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Showing posts from October, 2013

Software Defined Radio- SDR

Software Defined Radio (SDR), mainly receivers are what really got me back into amateur radio earlier this year, after a 40 year absence. I had a brief revisit to radio 10 years ago, when I was medically retired, but was disappointed that so little seemed to have changed.
So I went and played (when I was able) with computers, audio, video, home cinema and satellite TV (and sport cars) instead. But once I had done about all I could do there, I was after something new.
Then I re-discovered radio starting with the TV dongle software defined radio, rtlsdr.
While I am still annoyed that mainstream transceivers (that I could afford; or justify) are still little changed, SDRs really are a hoot; you can see what is out there- lots of really weird stuff and no dial twirling hoping to find anything of interest.
I started with the TV dongles; they are not to be dismissed lightly, a couple of MHz bandwidth, 60 MHz-1200GHz range, all for $20. I bought a discone antenna and put it up as high as I could…

Low-cost Amateur Digital Television- DVB-T ATV using UT-100C transmitter USB dongle

I am setting up a DVB-T tx on the atv channel on 70 cm. I am using a UT-100c USB dongle http://www.hides.com.tw/product_eng.htmlhttp://www.idealez.com/hides/product-detail/en_US/69859. It is only US$169 and produces 1 mW of DVB-T output. The software is at https://drive.google.com/folderview?id=0BzoVnSl8XNdQMmZPbDhEczA2RjA&usp=sharing. There are some pdfs of the device and how the software works. To use the dongle, only the windows driver and PC2TV are needed. With PC2TV, only the video works at the moment. PC2TV takes a deal of setting up but will work with a PC/laptop webcam.
Only the UT-100C dongle is needed to start. Some ordinary domestic DVB-T receivers can be used. The DVB-T channels in Australia are 7 MHz wide, the same as free to air TV.
As such, the standard Australian DVB-TV settings can be used. At 1 mW, it is possible to xmit on a free commercial channel and tune a TV to it, without causing any dramas. However, to work on the 70 cm channel, a TV dongle or set top box tha…