madengr

Why? From a quick review of the videos, he has added some impressive features such as harmonic balance and planar EM. Then again, it’s nowhere near the professional tools such as Microwave Office, so I’ll continue to pay for those.

The private business are using public right-of-ways and spectrum to carry their data, so they ought to be held to the same standard that makes cable television provide public access channels. If Google censors me, maybe I’ll dig up their cable that runs through the right-of-way on my private property.

In engineering, its just as important to know what not to do. I am an expert at knowing how not to get rich.

"What sort of logic supports that American values are those held by a minority of Americans. What possible values suggest they are the normal ones?"

The US Bill of Rights.

Making a chip is like baking a cake with a 100 layers, one layer at a time, with 100 different ovens in a custom kitchen built just for that recipe. Each one of those ovens needs a 99.9% yield, to yield 90% overall. Not to mention all the cake books (i.e. the Process Design Kits) you give to your customers.

Shut down and disband that kitchen, and you need to start all over again, even if you bought the same equipment.

It’s also like an auto assembly line that needs 2 years to re-tool even if 80% if the equipment is the same.

The fab is a giant, finally ticking machine with thousands of process steps all requiring 99.999% yield.

I actually had a pager add-on PCB in my Palm Pilot. Worked great.

Minimum wage was never intended to cover all the above, and it never has. Minimum wage is for teenagers working after school or weekends, or students with no (yet) marketable skills.

The suburbs, away from COVID and riot prone areas.

It will be interesting to see/do a teardown of this. I'm wondering if the UWB is separate from the Bluetooth (which I assume is 5.0), though it's probably in a single ASIC.

This claims the UWB is at 6 and 8 GHz, but they fail to show the antennas.

https://www.techinsights.com/blog/apple-iphone-11-pro-max-te...

Now we see that Apple patents slot antennas; what a load of shit:

https://www.patentlyapple.com/patently-apple/2020/08/apple-p...

I recall it also used 386 protected mode as you had to boot it from floppy, which was probably the first for a commercial game.

This and F15 were amazing games of the time. I bought the full thrustmaster setup for these.

The polish sausages were better than the hot dogs, but they killed them.

Why is it to broad to be accomplished? It seems to cover your typical BSEE, and you need an exposure to all of it.

Razavis RFIC is a good one too, but that’s really getting too specialized. Pozar is good for undergrad microwave.

Unless you want RF materials, or something other than G10/FR4. The cheap prices of aggregating everyone’s boards comes with the lowest common denominator of material.

Even the 4 layer board processes are not set up for good power integrity. They have a center core for layers 2 and 3, with 1 and 4 as foils. It ought to be two cores with prepreg between, giving the low impedance for internal power planes.

Do you still have them? Back in the 90’s when HP was discontinuing them, I bought 4x 32sii. I still have them un-opened. I still have my dads LED one from the 70’s. They are collectors items now.

Yep, had my Radio Shack calculator stolen from a college lab in 1990. Replaced it with a 32sii. After 30 years of RPN, I can never use a normal calculator. They are horrible.

I tried KiCAD, but having used Altium for 26 years, I’m sticking with Altium. KiCAD could not do simple things like assign nets to arbitrary polygons, which is critical for RF layouts. The DRC was really lacking too.

Of course it’s probably great for an open source project, but I don’t know anyone using it professionally. We have 20 Altium license at work, and I have one at home for my consulting business. Even at $2k/year maintenance, that’s cheap compared to the other RF software I use.

The whole problem with free CAD software is you’ll never get the cross discipline skills needed to develop it without paying someone. For example you need an expert at electromagnetics AND scientific programming AND UI design, etc. That’s a full time job, not a hobby. There is a ton of domain specific knowledge.

Yep, I work in hardware design for defense. They dropped the Cadence license (no RFIC design for me), but I got to take Unconscious Bias training yesterday.

The sub comms are at 25 kHz, which is 3000m at 1/4 wavelength. So 2 miles makes sense for a 1/4 wave monopole with the Earth as a counterpoise.

Uplink Downlink is a good, technical history:

https://www.amazon.com/Uplink-Downlink-History-1957-1997-033...

I'm the shadow banned commenter, due to comments that fall in the right half of the plane; disagreeable to HN mods.

But not to digress, it's likely 120 degree BPSK (i.e. QPSK with a DC level for the Q). I'm not in the deep space field (but do RF/Microwave professionally), but the DSN (deep space network) on Earth sends out a carrier with 120 BPSK modulation with PN (pseudo noise) code. The spacecraft transverts and sends that back (a bent pipe). Velocity is determined via Doppler shift of the carrier. Range from the delay in the PN code. So knowing velocity and range (and bearing using antenna pointing or interferometry), you can track the spacecraft with great precision.

Even without a bent pipe, you need carrier recovery first, before you can demodulate, and the leakage helps with that. You can also do geolocation with carrier leakage (e.g. ARGOS satellites) and via isodops (contours of constant Doppler shift) like a reverse GPS uses isochrones (contours of constant time delay).

So in short, there are benefits of wasting carrier energy. The ham guy can detect it as he can do lots and lots of coherent averaging (i.e. long FFTs or very narrow resolution bandwidths) to find that carrier. Though to recover any modulation will take a much bigger (or lower noise temp) antenna.

He is detecting, not demodulating, which is what the big dishes are for. Most deep space comms have carrier leakage (on purpose) for ranging. That’s likely what he is detecting.

What process is Xilinx using; not CMOS?

Fractal antennas are mostly snake oil. You’ll always see then driven against a large counterpoise (ground plane), as the counterpoise becomes the radiator. You can make use of Chu’s limit without resorting to fractals.

https://en.m.wikipedia.org/wiki/Chu–Harrington_limit

Not really. I just built a 256 element array covering 2 octaves BW. The feed board is seven layers. Arrays are lots of repetitive circuitry. I think the impressive part are getting microwave RFIC for pennies.

Now this PCB is crazy:

https://youtu.be/nurL3N1Etuc

I had a Radio Shack scientific calculator about that same timeframe. It was stolen during a lab. I then bought a 32Sii. Just wanted to thank the thief, as I likely never would have been a lifelong RPN user.

The retro-rockets on 1976 Viking lander in Mars don’t count? Of course that had a parachute to assist, but I think it was still going really fast.

Everywhere. There is a big DMR network here in Kansas City, and Fusion too.

http://c5.byrg.net/WP_BYRG_WWW/byrg-repeaters/

http://www.kansascityroom.com/Repeaters/

Well, once you use RPN, there is no going back. I truly despise normal calculators. I’d hate entering expressions anyway.

Well it also may be the key layout. After years of using a certain HP calculator, you get used to the layout. I prefer the 32Sii. Some have primary keys for x^2, x<y, 1/x, PI, etc. if I designed my own I’d have 10^x and LOG(x) as primaries. All depends on what field one works in.

Anything non RPN sucks anyway.

I’m an amateur radio operator, so about 3 years ago, I spent the weekend going through the house getting rid of items that interfere with the HF spectrum. I found:

Two network switches, laptop power supply, dishwasher, streaming music device.

My receive antenna (active loop) is about 50 feet from the house. I’m still not satisfied with the interference levels, but it’s not coming from me.