On Mon, 1 Apr 2024, Just Kant via cctalk wrote: I had a Tektronix 512, and an NLS215 (battery powered portable) from a company that switched over to making Kaypros.  I gave it away at one of the first VCFs. I guess that the vintage ones are no longer adequate.

On Mon, 1 Apr 2024, Just Kant via cctalk wrote: I had a Tektronix 512, and an NLS215 (battery powered portable) from a company that switched over to making Kaypros.  I gave it away at one of the first VCFs. I guess that the vintage ones are no longer adequate. -- Grumpy Ol' Fred

I still have a TEK 475A (with the DMM4 on top) and a TEK 11043A mainframe scope.

Except for the EMP. It'll theoretically render such devices nice looking, well-built scrap. The old completely vacuum-tube-based, discrete component oscilloscope from back in the day may actually survive such an event if it's outside the blast radius but still reasonably sheltered; and you are also outside lethal fallout zones, or can shelter and survive in radioactivity-safe places for a long time. Stock up on quality-made (e.g., Tektronix, Hewlett Packard) tube and cold-cathode-based test equipment (VTVM, oscilloscope, etc.) as well as quality radios and transceivers. Hopefully they will continue to serve as interesting artifacts of a time gone by, but if something were to go sideways in our world, they could potentially come in very handy.

Will things like PDAs and tablets, powered off and stored inside steel ammo boxes survive?

On 4/1/24 17:42, CAREY SCHUG via cctalk wrote: Yes, as will most contemporary electronics, even without elaborate protection. The amount of current induced in a device by EMP is a function of the number and length of conductors; most modern electronics are unlikely to have an issue given relatively short conductor lengths. Automotive ECUs, in particular, are unlikely to be affected, as they're equipped with seriously clamped lines and generally have been tested in lightning simulators (EMP looks like lightning, but EMP has a much faster rise time, much higher voltages, and vastly higher currents); likewise the commercial electrical grid is likely to be largely unaffected due to existing lightning protection. If your device can withstand a nearby lightning strike, it's probably going to survive a high altitude EMP event. The biggest problem for semiconductor devices is from neutron flux when under power, hence weird solutions for military systems where a PN diode will be used to trigger a crowbar on the power supply (ionizing radiation arrives well in advance of the neutrons). The upshot is that warfighting systems will recover, although the same probably can't be said for the warfighters. Yes, I spent entirely too much time in this space in my misspent youth. Note that none of this is to suggest that all electronics will survive, but the doom and gloom people associate with high altitude EMP, and Carrington events in particular, are generally overblown. -- Christian Kennedy, Ph.D. chris(a)mainecoon.com AF6AP | DB00000692 | PG00029419 http://www.mainecoon.com PGP KeyID 108DAB97 PGP fingerprint: 4E99 10B6 7253 B048 6685 6CBC 55E1 20A3 108D AB97 "Mr. McKittrick, after careful consideration…"

Accordimg to certain individuals on this list, going back a few years, electronics/computers can be damaged due to an electrical storm, presumably very intense activity, even while off. Go look through the archives.

Some years ago we had a lightning strike on the driveway next to the house. It took out every single device directly or indirectly connected to the cable TV (also Internet) connection. The reason was something I knew about but which I did not sufficiently understand: the cable TV connection came into the house at the opposite end from power and telephone, and was grounded there. A lightning strike will set up a voltage gradient in the soil near the strike, so the "ground" seen by power and phone was at a very different voltage than the "ground" seen by the ground rod "protecting" the cable TV entry. The resulting current actually evaporated the cable TV surge protector innards, and took out TV, printer, cable modem, Ethernet switch, PC, and a bunch of other things. Lesson learned: I rerouted the cable TV to go first to the power entry point, and attached its protector to the same copper ground sheet that the other two protectors sit on. A great reference for all this is the handbook "The grounds for lightning protection" by Polyphase Co., a maker of professional lightning protection devices. I haven't done everything they call for -- for example, our house doesn't have a perimeter ground. But it does now have single point grounding, and as a result we've had no trouble even though there have been plenty of lightning strikes in the neighborhood. paul

I found a somewhat different book from Polyphaser:https://w5nor.org/presentations/PolyphaserGuide.pdf which cites the other one in the references section in the back. The material looks rather similar to the older book; I recognized a number of illustrations. It has more content, it seems, and more recent material. The exact title is "The Grounds for Lightning and EMP Protection" by Roger Block, and searching for that title yields some sources, including a used copy on eBay and an online copy on Scribd. paul

On Apr 2, 2024, at 1:30 PM, Jay Jaeger via cctalk <cctalk(a)classiccmp.org> wrote: Paul, would you mind if I shared this on the Facebook EndFed Halfwave Antenna group? Time and time again I see folks talk about putting in ground rods in for antennas and NOT bonding them to the electrical service ground rod. In most (if not all) locations in the US, this kind of bonding is now a required part of the electrical code, and newly constructed houses (or ones that have their panels replaced) will typically have a "service ground' bus bar installed near the electrical panel. (The ARRL book is a pretty good resource on this topic, too, but real life experience may convince some to think twice about what they are doing.) https://www.arrl.org/grounding-and-bonding-for-the-amateur JRJ On 4/2/2024 10:13 AM, Paul Koning via cctalk wrote: > >> On Apr 2, 2024, at 11:01 AM, Jon Elson via cctalk <cctalk(a)classiccmp.org> wrote: >> >> On 4/2/24 00:03, Just Kant via cctalk wrote: >>> Accordimg to certain individuals on this list, going back a few years, electronics/computers can be damaged due to an electrical storm, presumably very intense activity, even while off. Go look through the archives. >>> >> I have had two incidents where nearby lightning strikes blew out components on gear I had. Many years ago, I had two computers connected by a parallel port cable, and chips on both ends were popped by a strike that might have hit power lines about two blocks away. >> >> About a decade ago, we had a lightning strike that hit trees half a block away. It took out an ethernet port on one computer, and blew out a bunch of stuff on a burglar alarm I had built. Both involved long wire runs. > Some years ago we had a lightning strike on the driveway next to the house. It took out every single device directly or indirectly connected to the cable TV (also Internet) connection. The reason was something I knew about but which I did not sufficiently understand: the cable TV connection came into the house at the opposite end from power and telephone, and was grounded there. > > A lightning strike will set up a voltage gradient in the soil near the strike, so the "ground" seen by power and phone was at a very different voltage than the "ground" seen by the ground rod "protecting" the cable TV entry. The resulting current actually evaporated the cable TV surge protector innards, and took out TV, printer, cable modem, Ethernet switch, PC, and a bunch of other things. > > Lesson learned: I rerouted the cable TV to go first to the power entry point, and attached its protector to the same copper ground sheet that the other two protectors sit on. > > A great reference for all this is the handbook "The grounds for lightning protection" by Polyphase Co., a maker of professional lightning protection devices. I haven't done everything they call for -- for example, our house doesn't have a perimeter ground. But it does now have single point grounding, and as a result we've had no trouble even though there have been plenty of lightning strikes in the neighborhood. > > paul >

On 4/2/24 00:03, Just Kant via cctalk wrote: I have had two incidents where nearby lightning strikes blew out components on gear I had.  Many years ago, I had two computers connected by a parallel port cable, and chips on both ends were popped by a strike that might have hit power lines about two blocks away. About a decade ago, we had a lightning strike that hit trees half a block away.  It took out an ethernet port on one computer, and blew out a bunch of stuff on a burglar alarm I had built.  Both involved long wire runs.

On 4/2/24 00:03, Just Kant via cctalk wrote: I have had two incidents where nearby lightning strikes blew out components on gear I had.  Many years ago, I had two computers connected by a parallel port cable, and chips on both ends were popped by a strike that might have hit power lines about two blocks away. About a decade ago, we had a lightning strike that hit trees half a block away.  It took out an ethernet port on one computer, and blew out a bunch of stuff on a burglar alarm I had built.  Both involved long wire runs. Jon

On 4/1/24 17:42, CAREY SCHUG via cctalk wrote: Yes, as will most contemporary electronics, even without elaborate protection.