Hello Mr. Okum
Yes there is an interesting device, of which millions were made. It was the RCA Analog to Digital box sold at K-Mart and Wal-Mart for $50; many were given away paid for by Congress. The third generation had a tuner using the SN761668 from Texas Instruments. I bought several of them, eventually removing the tuner from the motherboard, hacked them, getting the tuner to operate off the motherboard on its own without the BroadCom decoder ship. The tuner chip is controlled by I2C and the Tuner box has a very good LNA Antenna Amp. The output from the Tuner is filtered 44 MHz IF passed through a very good IF filter. However, the raw output (before the filter) from the Tuner chip can be used as an I/Q Zero IF SDR with the appropriate programming offset. Attaching the Raw output to a stereo audio input on the computer for I/Q provided excellent reception and very agile frequency shifting. Using a 96 KHz input PCI audio board, the SN761668 tuner would convert the entire VHF and UHF bands with very good AGC Gain and superior image rejection. I eventually abandoned the project when I realized it was too technically difficult to use this tuner, even though it showed excellent performance and provided 24 bit/96 KHz SDR for my computer. Perhaps it could be adapted to a Arduino controller so it could be packaged as a standalone SDR without all the support circuits I had to interface to it to get I to work for me. http://www.ti.com/lit/ds/symlink/sn761668.pdf From: [email protected] [mailto:[email protected]] On Behalf Of Michael Okun Sent: Wednesday, March 19, 2014 6:09 PM To: Jay Salsburg Cc: [email protected] Subject: Re: EBay US$25 DVB-T gizmo with video out and USB host feature Ooh... thanks the links! Interesting. Man it would be cool if it some of these cheap boxes had signal processing hardware that could be appropriated for more general sdr use... they must have some reasonable abilities if they're doing realtime video decoding, though I guess it's pretty likely that dvb-t decoding is specifically baked into the chipsets. I wonder if any of them might be running a Linux kernel on some kind of SOC.... Cheers, Michael On Wed, Mar 19, 2014 at 3:58 PM, Jay Salsburg <[email protected]> wrote: Now this box appears more promising (as a hacked SDR). http://www.firebird-systems.com/graphics/dct220/dct220-dvbt-terrestrial-digital-tv-tuner-hdmi.shtml Tuner: * Input frequency: 48-862MHZ * RF Input level: -25 to 82dBm * IF Bandwidth: 6MHz to 8 MHz * Modulation: QPSK, 16QAM, 64QAM Video: * Decoding formats: MPEG4, AVC/H.264 HP@L4, MPEG2 MP@ML/HL * Output format: 576P, 720P, 1080i, 1080P 50Hz * Aspect Ratio: 4:3, 16:9, auto * Output port: HDMI (V1.3C), YPbPr, CVBS, TV SCART Audio: * Decode format: MPEG-1(layer1&2&3), WMA, AC3 * Audio output: S / PDIF (Coaxial), RCAx2 (L/R) USB2.0: * Supported capacity: unlimited * Supported media: MP3, WMA, JPEG, BMP, AVI, MKV Power: * Supply Voltage: 100-240V 50/60Hz * Max. Power consumption: 10W * Standby consumption less than 0.85W (true standby) From: [email protected] [mailto:[email protected]] On Behalf Of Michael Okun Sent: Monday, March 17, 2014 12:39 AM To: [email protected] Subject: EBay US$25 DVB-T gizmo with video out and USB host feature This looked interesting... anyone seen one of these or know what's inside...? If nobody knows, but it there might be a chance it's an rtl with potentially hackable processing hardware, I might be tempted to buy one and post some board photos... (I follow some sdr lists, but don't post very often, so my apologies if this isn't quite the right place for this) Item: EU plug Digital TV Box LCD/CRT VGA/AV Tuner DVB-T Free View Receiver Converter <http://pages.ebay.com/link/?nav=item.view&id=201025062134> URL: http://pages.ebay.com/link/?nav=item.view <http://pages.ebay.com/link/?nav=item.view&id=201025062134> &id=201025062134 Cheers, Michael _____ No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.3462 / Virus Database: 3722/7202 - Release Date: 03/16/14 _____ No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.3462 / Virus Database: 3722/7216 - Release Date: 03/19/14
