Radio Program / Podcast Friday

I am on a well-known broadcast/podcast, I think Friday. If you are concerned that I haven’t given someone credit or that history has been misrepresented: I was recorded for three hours, and what they called me to fact-check would be just a few minutes on the air. The producer was really nice and did his absolute best, and I probably did say what you wanted, and because of time constraints of a 15-30 minute program where I was only one of several guests, very little made it on the air. History was also simplified by the program to make it comprehensible to the audience, for example USENET became a bulletin board and postings became tweets.

I do my best for the community with the press that I frequently have to deal with. Much of the community rarely deal with the press and aren’t aware of the issues, the main one being that I can only very rarely get them to say all that I want, the way I said it, and that my words generally pass through a reporter, an editor, a proofreader, and maybe other people before you read them.

Radio Antennas and Anti-Seize Compound

Amateur Radio operators like to put antennas outside and in the air. Once there, we might not be able to reach them for a long time. But someday they will need to be serviced or disassembled.

Not everyone learns right away: you should use anti-seize compound when assembling your antenna. It should go on every mating of two fasteners, and every place where a tube slides into another tube. Anti-seize compound is a special lubricant, sometimes mixed with microscopic copper, zinc, aluminum, or nickel powder, which keeps metal fasteners from getting stuck. I once disassembled an antenna that had been left in the air for 15 years, at a site a couple of miles from the ocean and its salt spray. Because the assembler had diligently used anti-seize compound, the entire thing came apart easily, and all of the fasteners, probably stainless steel, could be reused.

You should be using stainless steel fasteners for things that live outside, as these will best survive an extended time outdoors without becoming a lump of rust. But stainless steel has special needs: The friction of two threaded stainless steel fasteners mating causes galling, microscopic debris that can lock two fasteners together, or they can cold-weld, which causes the two surfaces to fuse together. So, stainless steel fasteners always need anti-seize compound to preserve their ability to be disassembled.

Similarly, you should use anti-seize when you mate antenna parts like nesting tubes together. Or don’t expect them to come apart again in a decade.

Some people are concerned about the conductivity of the anti-seize compound, even going to the trouble of measuring its DC conductivity with an ohmmeter. This is a little naivé, because antennas carry RF, not DC. The metal-filled kind of anti-seize compound is more conductive, obviously, but in general you don’t need to be concerned about its conductivity. The metal parts of the antenna will generally DC-couple even in the presence of a non-conductive lubricant, the contact surfaces just push it aside and the lubricant fills gaps. And even if they didn’t, the capacitive coupling between the metal parts would be sufficient. Metal parts are in general not bare metal: both stainless steel and aluminum resist rust because of a protective oxide coating that they form immediately when they contact air. But these parts maintain DC electrical contact even though their oxides are insulators. They rub it off, or it’s too thin to matter.

What is the best anti-seize compound to use for antennas? Most anti-seize compound is designed for other applications, in particular use in automotive engines. So, you’ll see it rated for use with temperatures in the thousands of degrees Farenheit. Obviously we don’t need this for our antennas that probably won’t exceed 150° F.

However, our antennas are outdoors in a harsh environment. Acid rain is everywhere, and birds drop guano on antennas that becomes phosphoric and nitric acid through bacterial processes (for the bio heads: denitrification, glycolysis, probably others). When you have two different metals touching each other, and acid, you have all of the parts of a battery: a cathode, an anode, and electrolyte; and the result is galvanic corrosion, a form of electrically and chemically accelerated rusting. Even mildly impure water is sufficient to be the electrolyte, so the potential for galvanic corrosion is everywhere that dissimilar metals touch.

It’s a characteristic of the electro-chemical reaction of a battery that the anodes donate electrons to the circuit and the cathodes receive them. Anodes corrode as they lose electrons, and the cathodes may get coated with some chemical by-product, but generally cathodes don’t corrode. In our antennas combination of two metals, one will be the cathode and one the anode. Which is which? You figure that out with the galvanic series, a table of which metals are better, or worse, electron donors. But why would you need to know?

A very common strategy for defeating galvanic corrosion is the use of a sacrificial anode. For example, most boats and water heaters contain one, and you’ll sometimes come upon a marked cover for one in the street, as they’re used to protect most underground infrastructure. The sacricifical anode is generally zinc or magnesium, as those are on the bottom of the galvanic series. That means that other metal connected to the sacrificial anode will be a cathode and won’t be subject to galvanic corrosion, while the sacrificial anode will be, sacrificing itself for the good of the cathode!

So, this brings us back to the anti-seize compound. As I mentioned, these are available with zinc filling, aluminum, copper, or nickel. Our antennas are generally aluminum. Copper and nickel are both above aluminum on the galvanic series, and thus in combination with them, our aluminum antenna part would be the anode, and would be subject to galvanic corrosion in combination with copper or nickel anti-seize. This might be micoscopic, but the result is going to be rougher surfaces when we try to disassemble two nesting tubes. What if we use zinc-filled anti-seize? Zinc is below aluminum on the galvanic series, and thus the zinc would be the anode, and maybe some of the zinc in the anti-seize will sacrifice itself to keep our aluminum antenna parts pristine as acids intrude into the connection. So, I’m going to use zinc anti-seize on my antenna, even though a lot of hams swear by Jet-Lube SS-30, a fine brand of copper anti-seize sold by, among others, DX Engineering.

An alternative is the aluminum-filled anti-seize sold by InnovAntennas. In the joining of two aluminum elements there would be no dissimilar metal issues. However, entertainingly their own catalog page shows the elements secured with a stainless steel pipe clamp, making it clear to me that there would still be dissimilar metals issues. I’m going to stick with zinc where the pipe clamp would be, and with any dissimilar metal contact, but maybe this aluminum paste is a good idea for between the elements. Permatex also makes an “Aluminum” anti-seize, but they describe it as a blend of aluminum, copper, and graphite, so I assume it’s called “Aluminum” because it’s intended for aluminum engine blocks.

When would copper anti-seize be appropriate? Well, I think it’s made for car engines, where heat is a problem and the main material used is steel. Jet-lube might have been designed for aviation, back before aluminum was in as much use. Steel and iron are above copper on the galvanic series and thus copper could be a sacrificial anode. Engines often have a large sacrificial anode, or more than one, somewhere within both their oil and cooling circuits, and this will often be zinc or magnesium.

Copper anti-seize is also appropriate for stainless steel antenna parts, at least the ones that don’t touch aluminum. Zinc would work at least as well, including for parts that touch aluminum.

There are places that anti-seize doesn’t belong: don’t put it on moving parts, and don’t bridge things that are supposed to be insulators with it. That means definitely don’t put it on your coaxial connectors! Don’t put it where it might collect lots of dust, it’s meant for where metal is permanently mated with other metal, and won’t help elsewhere.

Mr. Armaan Premjee and Richland Acquisitions Offer To Buy Your Land, But They Don’t Mean It

I received a two-page “offer” in the mail of $47K for some real-estate I own, with a contract ready to sign. It wasn’t a real offer. I’ve done some analysis so that other folks can understand what’s going on when someone out of the blue sends you a letter offering money for your property.

The offer was from Richland Acquisitions of Dallas, Texas, owned by one Armaan Premjee. You can see a YouTube video of Mr. Premjee explaining his business here. He claims to be a “wholesale” land flipper. It seems that sometimes he actually does buy land. He just doesn’t buy all of the land for which he sends offer letters. Or maybe not much of it. Which seems deceptive to me.

What you read here is all my opinion, and I am neither an attorney nor a real estate expert. I’ve been sued for defamation before, so I am careful to stay on the right side of the 1st Amendment and the California anti-SLAPP law. (I won my case, and the court made the guy who sued me pay $315,000 for my defense.)

Mr. Premjee and his company’s offer included a contract that I would have been required to sign by April 10 if I wanted the money. It was March 20 when I received it. It had a few interesting things:

  • It was binding on me, but it allowed Mr. Premjee and his company to back out any time right up to the final closing date, for any reason.
  • It had a maximum 112-day delay between contract acceptance and closing, when I would supposedly get paid.
  • It included a term allowing them to advertise my property before they actually paid for it.
  • It included the fact that there could be a “double closing”. I think this means that they may sell your property to someone else at the same time that they buy it.

I wrote to Mr. Premjee asking for the name of his escrow company and why there was a 112-day delay between the contract acceptance and closing. I quickly received an email back from one “Brian Smith” stating “After taking a closer look at the property we have decided it would not be a good fit for us.”

So, the offer wasn’t real. I can guess a few things from this:

From the video referenced above, it’s clear that the letters are sent out in bulk. He talks about making offers in “entire counties” and scaling to “entire states”, for a set of properties in those areas that fit his initial parameters, stated in the video, things that make the property more easily buildable and more likely to sell.

Although the letters appear to be offers, I don’t believe that Mr. Premjee and his company have performed their full due diligence on the property before making the “offer”, as indicated by Mr. “Smith’s” email quickly rejecting my property once I inquired about it. They make no commitment to actually go through with the offer. So, for all of the people who return signed contracts, it sounds to me that Mr. Premjee and his company then take a look at the properties and decide which ones they are interested in, and maybe at what price.

And what about the “double closing?” One of the contract terms allows Mr. Premjee and his company to advertise your property before he actually pays for it. So, it sounds to me like the “wholesale” part is that he actually gets his own buyer for your property before he pays you for it, buys and sells at the same time, and pockets the difference. And perhaps if it doesn’t sell in those 112 days, he doesn’t buy it at all.

OK, clever “system”, as he calls it in the video, but in my opinion somewhat shady, because it’s not explained to the land owner what is really happening, and that the offer isn’t really an offer. Probably nothing illegal but I will check with the California Department of Real Estate.

Post-Open License: First Draft

At the link below is the first draft of the Post-Open License. This is not yet the product of a qualified attorney, and you shouldn’t apply it to your own work yet. There isn’t context for this license yet, so some things won’t make sense: for example the license is administered by an entity called the “POST-OPEN ADMINISTRATION” and I haven’t figured out how to structure that organization so that people can trust it. There are probably also terms I can’t get away with legally, this awaits work with a lawyer.

Because the license attempts to handle very many problems that have arisen with Open Source licensing, it’s big. It’s approaching the size of AGPL3, which I guess is a metric for a relatively modern license, since AGPL3 is now 17 years old.

Send comments privately to bruce at perens dot com.

License Text

Linux on HP Sceptre x360

February, 2024.

I purchased an HP Sceptre x360 16′ laptop with 3840×2400 UHD+ display. I got this because it was affordable and had about the highest resolution display unless there is some exotic and unaffordable 8K laptop out there. I am mostly doing 2D web graphics development.

For some reason this laptop came with the display disabled in BIOS, and at first presented a disappointing black screen when turned on. I think it was Fn-F12 that finally turned on the lights, or it might have been holding down the power button for long enough for the machine to clear the BIOS parameters. Perhaps this is why Best Buy offered an $800 “open-box” discount on what was obviously not an opened box. Once it booted into Windows and ran it initial software update, it immediately went into an HP BIOS updater and reflashed the BIOS.

Debian 12 installed and ran.

The processor is a 13th Gen Intel(R) Core(TM) i7-1360P. This is a hybrid CPU, the cores all run the same instruction set but they aren’t all the same. There are 4 P (for performance) cores which have hyperthreading and run at high frequency. Because of hyperthreading, they each appear as 2 CPUs to Linux, but the CPU is only running one of the 2 threads at any time. Hyperthreading reduces the overhead of multiprocessing when there are more processes to run than there are CPUs. Without hyperthreading, switching processes would otherwise require flushing caches and reloading the registers and the virtual memory system. There are 8 E (for efficient) cores which run at lower frequency and are power efficient. The E-cores don’t support hyperthreading and each appears to Linux as 1 CPU. The Intel Thread Director hardware reports statistics on these processors to the Linux scheduler, which can then schedule them as appropriate. You can manually choose which are used with the taskset command.

There are several issues with this laptop because Intel has not yet properly supported its own hardware on Linux.

The keyboard can be folded back and the laptop used like a huge, heavy tablet. Gnome/Wayland recognize when the display has been turned on its side, but don’t recognize when it’s right-side up again! You’re stuck. I’ve not yet found what is missing and where.

The Xe graphics work well enough to stream movies and run WebGL. There is also a discrete ARC 370 graphics controller which is listed as a PCI device, but I’m not at all clear if it’s being used. A driver is available for Ubuntu (because some Dell laptops are certified to run Ubuntu) and may not yet be upstreamed. I will investigate further.

The Intel IPU6 integrated camera is an incredible dumpster fire. I’m not kidding. It’s an integrated 5MP camera. Sounds simple. doesn’t that? All of those use UVC and work with existing drivers, right? Well, not this one. In order to save a few dollars at most, this is a non-UVC camera, and a lot of what would be in embedded firmware on a UVC camera has to run in user-mode libraries. Sounds bad, right? It gets worse.

There is a repository full of proprietary Intel firmware and image processing libraries for the camera, even though there could be no business-differentiating value in a 5MP integrated camera design which would justify making it proprietary at this late date, and camera image-processing, including autofocus, is well-known art and available today for other cameras as Open Source.

There are four large Intel git repositories in total required for the camera drivers, one of which has the main branch empty, just to give you a hard time, and you have to figure out the branch to check out and then figure out all of the dependencies to build this stuff. This is at least an hour’s work. Another manufacturer might have listed all of the dependencies, put everything in one place, and made it work by just typing “make install”. What Intel has done is make it work only where they were obligated to do so. Which is Ubuntu and Windows. Everyone else might be able to figure it out from that. This isn’t good community member Intel that I’m used to.

Once you get all of that working, it is not so simple as just loading a driver. The camera needs a user-mode pipeline to do its processing. That connects to a Video4Linux loop device so that the camera can interface with existing software as if it were actually a kernel device. It depends on V4l-relay, which doesn’t appear to be in Debian so I’ll have to find that. You can configure udev to start this pipeline, but it doesn’t appear that Intel actually documented how to do so.

After you do that, there is some additional configuration necessary so that the browser can see your device, which Intel has not documented. Some folks figured it out for other Linux distributions, and it looks non-trivial, with a lot of files modified.

In the interim, I bought a UVC camera on Amazon which I will hang on the back of the display, until some other poor soul in the Open Source world works this out entirely. Which Intel really should be doing with paid staff for more than just Ubuntu.

Requirement for SVG Designer

This is a solicitation I am making to SVG artists. If you can fulfill it, please respond to bruce at perens dot com.

I am making a web remote control panel for two-way radios. Here is the meter I have already designed: I am now making knobs, buttons, and switches. When incorporated into my program, these will move appropriately for the device pictured. I’m not an artist, and could use some help. I worked at Pixar long ago, but was a systems programmer, rather than graphics, so I have some competence, but am not really a graphics expert.

What I would like, to start with, would be a knob. These are a good example: but I would like all of the rights to the SVG produced, and I have some specific requirements because the end result will be animated.

I’d like the SVG to be drawn with Inkscape, as that is easily available for people to modify the SVG. My program uses a canvas with the center at 0,0. I don’t think Inkscape can do that, but I would translate the drawn SVG to that origin for my program. The size of the canvas should be 1000,1000.

The knob should have a layer which is stationary and is a disc with a brushed metal effect and a beveled edge, a specular or distant light effect, and a layer which I will rotate by changing the transformation with my program. The rotating layer will be the pointer on the disc. It can contain other parts that rotate.

I will draw the scale around the knob with the same program that draws the scale on my meter demo, it can draw all sorts of scales.

I would like to be able to change the colors of the knob by modifying the SVG. I don’t know if you can do this, but if the brushed metal effect could be a transparent overlay over a solid color, that would work. If this works out, I am also looking for different styles of knob, and switches, etc.

Can you do that, and what would it cost?

Things A Parent Never Expects

My son admitted to his mother and I that he is a regular user of

Mustache wax!

OK, he went through Fire Science classes in high school, graduated high school with his EMT certificate, just in time for COVID, did 6000 ambulance calls, just got his Paramedic certificates, and he’s 22, 6’4″ and on track to work for a fire department. Where handlebar mustaches are somewhat popular.

We’re very proud of him. I just never expected to have a kid who uses mustache wax. 🙂

Utility Forgets It’s Mitigation Obligations

In the 1960’s, the East Bay Municipal Utility District, the provider of our water, and sewers for some districts, built the Woods Reservoir near where I live. Humorously, the acronym for our water company is EB MUD.

The Woods Reservoir included a half basketball court as mitigation – to contribute to neighborhood recreation in balance of the detriment to the neighborhood of a 3 Million Gallon steel-sided, wood-roofed reservoir sited on our otherwise residential neighborhood.

Over the years, EBMUD forgot its mitigation obligation and built its own infrastructure into the basketball court space. Finally, they sent a rather nasty sounding memo to the property owners in the neighborhood demanding that we remove the basketball stand that we illegally left on their property, or they would eject it on to our street (which is private property, not city-maintained). And stating that their reservoir was a “secure facility” and that we may not be there to play basketball.

A neighbor dug up to mitigation documents which will now be presented to the water district.

If you live near any sort of mitigation, it’s important to save documents and make sure they are transmitted to new homeowners when properties are sold.

Signed off Twitter

I’ve signed off of Twitter. They seem determined to sell themselves to Elon Musk, whom I will listen to about rockets and cars, but he’s quite the asshole regarding politics and many other topics.

It’s surprising how many people don’t know my email, which is almost the same as my name: bruce at perens dot com. Please feel free to write.

My phone is also pretty close to my name: +1 510-4-PERENS. Mind the US-Pacific time zone, please. It will tell you if you don’t.

There is also a cell phone for texts, which you can ask for via email.