drmpeg

14 ms·

211.
by drmpeg 4y ago
B-frames (bi-directional predicted frames with a reference frame in both the past and the future) are patented. I'd say that's a process or method.
212.
by drmpeg 4y ago
Here's my favorite vehicle from the Jacques Littlefield tank collection. A Russian P-40 radar. https://www.w6rz.net/DCP_1040.JPG
213.
by drmpeg 4y ago
There's an old saying in ham radio. "If you want to make a small fortune in ham radio, start with a large fortune".
214.
by drmpeg 4y ago
> There's good news: 5GHz is not an ISM band. Part of the band is ISM. 5725 to 5875 MHz. https://www.ecfr.gov/current/title-47/chapter-I/subchapter-A...
215.
by drmpeg 5y ago
Years ago I had a Doberman / German Shepard mix that I paid $25 for at the San Jose flea market. An incredibly smart dog that never pooped or peed in the house, even as a puppy. She would just wake me up in the morning when she had to
216.
by drmpeg 5y ago
Software Defined Radio is a pretty steep learning curve. You need to know about RF, digital signal processing, math, software and computers all at the same time. On the GNU Radio Matrix server, we see Masters and Ph.D students have a diffic
217.
by drmpeg 5y ago
Thanks for pointing out band 40. Apparently it's just used in China, but it is supported on the iPhone 13. Band 30 is a no-go because the downlink is at 2350 to 2360 MHz, which is not a ham band. The ham band is split because of satell
218.
by drmpeg 5y ago
Dani is definitely smarter than the average bear. Also, I believe English is a second language for him.
219.
by drmpeg 5y ago
It's too bad srsRAN doesn't support TDMA (yet). LTE band 42 and the 9 cm amateur radio band overlap, so it would be legal for hams to run LTE/5G nodes. Having your phone being your first ham radio might be a great way to get
220.
by drmpeg 5y ago
Building a fire death machine using soviet military tech https://www.youtube.com/watch?v=UNisqZOAaAs
221.
by drmpeg 5y ago
Wide band HD spectrum painting. https://www.w6rz.net/spectrumpaint.mp4
222.
by drmpeg 5y ago
Here you go. However, noise and interference are two different things. https://www.w6rz.net/902-928MHz.mp4
223.
by drmpeg 5y ago
For those who want to do a deep dive, here's the altimeter test data. https://ecfsapi.fcc.gov/file/12070826325320/AVSI%20AFE76s2%2... https://ecfsapi.fcc.gov/file/12070826325320/AVSI
224.
by drmpeg 5y ago
5G isn't just millimeter wave. Over the next few years, the majority of 5G will be on the 2496 to 2690 MHz (T-Mobile on recycled Sprint spectrum) and 3450 to 3980 MHz (AT&T, Dish and Verizon on 3.45 GHz, CBRS and C-band) bands.
225.
by drmpeg 5y ago
I'll also recommend Rainbows End. I believe it contains a pretty good prediction of what millimeter wave 5G could become.
226.
by drmpeg 5y ago
Radar altimeters use frequency modulated continuous wave (FMCW) and the bandwidth is 20 to 170 MHz (the larger the chirp, the more accurate it can be). It's extremely difficult to have a 170 MHz wide filter at 4.3 GHz with a brick wall
227.
by drmpeg 5y ago
Steve1989MREInfo https://www.youtube.com/channel/UC2I6Et1JkidnnbWgJFiMeHA Nice!
228.
by drmpeg 5y ago
That's actually pretty wide. A popular rate for DVB-S2 is 333 ksyms/s or 400 kHz with 0.2 rolloff.
229.
by drmpeg 5y ago
The way I read it, it's 3 (or maybe 6) kHz on 10m and 20 kHz on 6m. The article is using 80 kHz.
230.
by drmpeg 5y ago
420 MHz (and above) is generally line of sight propagation. The frequencies mentioned in the article (29.25 and 51.7 MHz) are able to reflect/refract off the ionosphere and allow much longer propagation paths.
231.
by drmpeg 5y ago
We won't be able to make two-way contacts with European stations.
232.
by drmpeg 5y ago
Unfortunately, no amateur radio television below 420 MHz here in the US.
233.
by drmpeg 5y ago
I was able to get a /29 very easily here in Silicon Valley. However, when you ask for a /24, your local administrator usually wants to hear a good story as to why you need it. And of course, you do need to supply an amateur radio
234.
by drmpeg 5y ago
WWV also transmits on 25 MHz. This is an experimental transmitter that's not mentioned in the broadcast at minute 0. WWVH does not transmit on 20 MHz.
235.
by drmpeg 5y ago
Certainly not condoning it, but as long as you don't interfere with another user, you could get away with it. For the frequencies I'm using, the 3.4 GHz band is very lightly used by hams, so that won't be a problem. Plus wide
236.
by drmpeg 5y ago
Those frequencies that I'm using (2305 and 3429 MHz) are in amateur radio allocations, so a license would be required (entry level Technician license will do). Because of that, you can't run any encrypted traffic over the link. So
237.
by drmpeg 5y ago
Here's my 30 Mbps IP over UHF/SHF system. It takes advantage of a little known driver in the Linux media subsystem that exposes the RF link as just another Ethernet interface. Although not shown in the diagram, it also works with
238.
by drmpeg 5y ago
WWV and WWVH will be sending a new test signal on minute 8 for WWV and minute 48 for WWVH. https://www.youtube.com/watch?v=O3Q7L0TNGtk The test signal .wav file is available here: https://zenodo.org/record&#
239.
by drmpeg 5y ago
> And what's with CoreMark? The Nios V core is RV32IA. No multiplier.
240.
by drmpeg 5y ago
The 70 cm rule is the silliest. The limit for digital data is 100 kHz, but you can legally transmit 6 MHz wide analog television. Because wide bandwidth video is allowed, digital video modes like DVB-S, DVB-T and ATSC are also allowed. To g

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