Hot answers tagged

7

FCC Regulations, Title 97.307(f)(8) says yes, you can transmit with ATSC modulation in the US, BUT you can't use frequencies which match US ATSC channels. You would need to find a receiver (maybe PC controlled?) flexible enough to listen to amateur frequencies. As to DVB-T or DVD-S, well, they'll work with about 2MHz of bandwidth instead of the 6MHz ...


4

Here is some useful scholarly information about the signal attenuation (in dB) of EM waves through freshwater at various frequencies and depths. You will find a formula that you can use. You will also need to know the antenna gains, transmitter power levels, and the receiver sensitivity at the bandwidth. RF Path and Absorption Loss Estimation for Underwater ...


3

I've heard that 2 days in the lab can save 2 hours of reading but in this case it turned out to be easy to test. It is the sample rate of the SDR which changes the bandwidth of the signal. Since I am using the PLUTO SDR I can't go below around 500ksps. So I tried with a symbol rate of 300 kbaud at a sample rate of 600k. Able to demod successfully. I asked ...


3

SSTV could be an interesting answer here. Bandwidth requirement is about 30 KHz to reach your goal of 1 frame per second AND it's proven tech on HF bands... though you'll need to multiplex the video feed yourself (or another strategy) to use 30 KHz instead of the typical 3 KHz. This may be a great opportunity to use a loopstick antenna. Yes for transmitting. ...


2

Any antenna under water is creates a far more difficult problem than that of the main focus of the school project. I would put a WiFi transmitter (ESP32, et.al., inexpensive loss if drowned) on a float above the submersible, and run a fiber optic cable to transfer image files from the FPV camera (connected to say an inexpensive Raspberry Pi Zero that won't ...


2

Software defined radios (SDRs) that can transmit can certainly do this. In the GNUradio software, for example, there are blocks for receiving and transmitting ATSC; cf. this blog post for how to receive and decode ATSC with a SDR.


1

It depends of what signal do you want to receive: ATSC and DVB are digital standards and you have blocks and scripts to deal with as you have seen in the webpage you linked. DVB has a lot of different modulation and encoding possibilities and dealing with this in GNURadio is a bit of a headache if you do not know the exact parameters to begin with. You can ...


1

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 ...


Only top voted, non community-wiki answers of a minimum length are eligible