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4

Depends on the band plan and the repeaters operator. You wouldn't be violating any FCC rules, though, but if you're outside the US the answer may be different. To expand on this, you are allowed to transmit any permitted mode on any permitted frequency your license is good for. That frequency and mode happening to correspond to an open repeater another ...


4

So, a teaser first: With GNU Radio, you can transmit various DVB standards. Here's Alexandru Csete demoing his DVB-S2 transmission: As you can see from the FFT Plot generated by the flow graph in the upper picture, some 7MHz of bandwidth would be sufficient for this transmission mode – the HackRF should, like the device Alexandru used, be able to deal with ...


2

The signal interface with traditional hardware radios (such as those controlled by hamlib) is through an audio device (sound card). A glance at QSSTV's manual looks like it works that way. SDR programs generally output the demodulated audio to an audio device. Therefore, what you need is a loopback audio device, one which is used as an output by your main ...


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The SSTV transmissions were originally already scheduled for late December. I'm waiting for them, too. In the past, the ISS was relatively continuously transmitting pictures in a loop, the same 4-5 pictures multiple times with small (some minute long) breaks in between. It is very easy to spot the ISS signal in a waterfall, it's quite strong and you will ...


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MultiScan 3B works fine in terms of decoding. This being said I had some issues making it work with my external sound card for transmitting SSTV. For some reason transmitted images turned out to be cropped. I accidentally figured this out using cqsstv.com. Eventually I ended up using a Linux laptop and QSSTV software. Still if you are interested only in ...


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The TV is likely not emitting any information, but rather just noise. A TV from the 80s would have been a CRT set. These work by sweeping a beam of electrons through a raster scan. The aiming of that electron beam is accomplished by subjecting it to a controlled electric field, and as we know, radios are machines for detecting electric fields. Since the ...


1

The wiring would be identical to a cable for APRS purposes (software TNC on the phone). I haven't found anyone doing this but I don't see why it wouldn't be possible. You want an interface circuit to protect both devices, but it can be entirely passive. The two relevant protections are reducing the audio output to match the microphone input (series ...


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By programatically you mean through command line and/or scriptable ? I was looking for a linux app for DRM digital SSTV compatible with EasyPal and found TXRXAMADRM: http://pa0mbo.nl/ties/public_html/hamradio/txamadrm/ It comes with an executable for sending, one for receiving as well as a GUI wrapping them. Just managed to compile them but couldn't test ...


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With Amateur televison (ATV) one can transmit 800x600 pixels with 25 images ("frames") per second and thus have nicely moving pictures (for reference, NSTC is 29.97 frames per second). This requires a bandwidth of 6 MHz and can be done at frequencies starting at 430 MHz in different amateur bands. People also make use of NTSC and PAL modes. Wikipedia has a ...


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Just adding to the above answer: If you are going to transmit SSTV on a repeater that is also used for voice, you should try to be a courteous as possible: Make yourself aware of any popular nets that might use the repeater. Avoid sending SSTV during those times. Listen for a least a minute before transmitting. Turn down the volume on your SSTV generator, ...


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Appleton WI http://www.apleinc.com/WB9KMW/SSTV_2M.html Columbus OH http://www.qsl.net/n/n8tut//sstv/ Kokomo IN http://www.youtube.com/watch?v=UGVMJu_1MpI Sacramento CA http://www.n6na.org/nets/sstv-net And, a 2005 list, some of which are sure to be active still http://www.hffax.de/html/net.htm


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