N6OL

November Six Oscar Lima

Month: May 2025

Finally, a Real Update from PG&E

May 18, 2025 /

Though there’s still no damned excuse for PG&E taking more than ten months to send someone out to investigate the noise source at the PG&E Poplar substation near my QTH, I did get a call last week after my second letter to PG&E’s CEO and my case being escalated to a supervisor in the customer call center, who then raised the issue with a handful of other supervisors.  It shouldn’t be this hard to get someone to react at a public utility, but at least they finally did.

It turned out there had been some activity at the substation in an effort to resolve the problem between March 31 when the source of the trouble was confirmed, and when I finally got a call from someone who knew what was going on.  Evidently PG&E has a fairly terrible communications problem when it comes to information moving between the people who actually work on the issue and the customer-facing call center and ticket tracking system.

The trouble has been isolated to the vicinity of a 230kV bus at the substation, though in the intervening weeks they’ve also power washed and cleaned up some 115kV systems.  Evidently the trouble is that they cannot simply power-wash around the 230kV bus; to do so would risk a catastrophic arc flashover because of the sheer potential difference involved.  (230kV is a LOT of electrical potential.)  From the explanation I was given, it sounds like PG&E does not have a redundant system for this 230kV bus either.  They can’t work on it without shutting it down, and they also can’t just shut it down to work on it– to do so would shut down power at the substation for everyone it serves.

Given the lack of redundancy, I asked how they do routine maintenance on this system just in general, and the answer could be summarized as “rarely, and at considerable expense.”  The systems themselves are designed to have a very long MTBF, but on the occasions that they do need to shut them down, they have to plan it out months in advance, bring in a mobile unit of some kind (presumably either power generation or a busbar on a flatbed maybe?) to keep things working while the 230kV system is shut down for maintenance.  This apparently happens only once every 4-5 years and can be a multi-million-dollar operation.

That said, all hope is not lost: they’re trying to book their infrared team to come out and image the system while it is under load to see if they can spot any “hot spots” which might be addressable without something as inelegant as a power-wash, and they’re also looking to work with their high-tech services team to see if there are other ways they might suppress the RFI and keep it from being a nuisance in our neighborhood.

But lets be very clear about one thing: what PG&E is doing at the substation, though it may be very inconvenient to fix, is still a violation of FCC rules.  And it doesn’t matter if it inconveniences a handful of Ham Radio operators, shortwave listeners, AM broadcast enthusiasts, or a thousand people’s cell phones; the rules are the rules and they don’t distinguish by how many people are affected or how troublesome it may be to correct the root cause.  (That said, I do believe I’ve observed a correlation between noise emanating from the substation and reduced signal quality of KRCB-DT on ATSC channel 5, but I need more data to confirm it.)

The PG&E supervisor promised to keep me better informed going forward as they continue to work on the problem, which is a very different attitude than what I got from the rest of the company between May 16, 2024 and May 16, 2025 (it was in fact one full year to the day between my opening of a case about the substation and receiving a call from a supervisor on Friday).

That’s what I know for now.  More to come, I hope.

Real-World Example of PG&E / Electrical Utility RFI

May 15, 2025 /

In case you ever wondered what PG&E’s (or really an utility company’s) electrical arc noise sounds like on an actual radio, here’s a short video in which you can hear how that awful 120 pulse-per-second racket actually manifests in a real-world scenario:

I start out tuned to 3.560 MHz, which happens to be about where my 80/40/30/20m fan dipole antenna is resonant on 80m.  I’m using AM mode at the request of the folks at the ARRL for the purpose of documentation. Though this would normally be a lower-sideband segment of the band, it helps to hear the noise over the background static to decode as AM.

Toward the end of the video, I tune to WWV on 15 MHz, which is a bit above where my 20m antenna is resonant, so the reception isn’t quite as good.  When PG&E is not partying like it’s 1899 with their unintentional spark-gap transmitter, WWV is still clearly audible…  not so much when they are producing this RFI though.

It’s worth noting that this broadband noise doesn’t affect only the amateur radio spectrum.  I’ve charted it as low as 1600 kHz (AM Broadcast band) and all the way up to 450 MHz (UHF) and everywhere in between.  There’s a reason spark-gap transmitters are forbidden by international treaty, and this is it: electrical arcs produce tremendously wide signals and horrific broadband noise.  This noise affects AM and FM commercial broadcasts, Shortwave radio, government and public safety, VHF and UHF television, and even cellular phones.

My Letter to the FCC Regarding ATSC 3.0 and the Sunsetting of ATSC 1.0

May 4, 2025 /

It’s far from the most elegant thing I’ve ever written, but I think it gets my main points across reasonably well.  The due date for public comment is coming up on May 7!  If you want to leave a public comment:

While I sympathize with content providers’ desire to mitigate copyright infringement, I strongly disagree with their behavior thusfar when it comes to DRM-encrypted ATSC 3.0 broadcasts. The A3SA and NAB appear to be taking advantage of this crossroads in technology to reverse the status quo which has been in place since the advent of the VCR and the decision in Sony Corp. of America v. Universal City Studios, Inc., 464 U.S. 417 (1984), and in the process they’re reducing the utility of broadcast television as a public service over the public airwaves.

As it stands today, despite many channels in the San Francisco Bay Area broadcasting from the ATSC 3.0 “lighthouse” on ATSC channel 7, I cannot tune most of these channels at all– DRM has been taken to its logical conclusion and the content cannot be received, despite my receiver being ATSC 3.0 capable. The reason? I, like countless other consumers, use a home-networked tuner, and the A3SA has failed to work with manufacturers of network tuners to ensure that they can receive their DRM-protected content.

So not only can I not record broadcasts for time-shifted viewing, like I’ve been able to do since the 1980’s, I can’t even watch them live via the more-reliable ATSC 3.0 signal.

The courts have already ruled that time shifting for one’s personal viewing qualifies as “fair use” and now the NAB & A3SA are trying to use new technologies to eliminate fair use for their own benefit with no regard for the viewing public, who own the airwaves.

Many claims have been made about the necessity of DRM-protecting these signals, and yet, the recording of live television, both on analog and digital media, has been a common practice for more than 40 years. What’s changed is an opportunity arising for content providers to wrestle back control from the viewing public. But in placing so many restrictions on protected content, they’ve rendered their own broadcasts unviewable by a large percentage of the public.

I have additional concerns about their plans to disseminate encryption keys over the Internet. There are many reasonable privacy concerns for why consumers may not wish to have their televisions or tuners connected to the Internet 24×7 or even temporarily to retrieve an encryption key (which reveals the intent of the requester to watch a particular stream); moreover, in the face of an Internet outage, this could render it impossible for consumers to watch television at all. In an emergency situation, where broadcast television might be the only way for the public to be informed, for example in the face of a natural disaster, terrorist attack, or regional power disruption, losing the ability to decrypt an encrypted signal could expose consumers to unnecessary risk of harm or loss of life.

Lastly, on a technical note, the methodology for streaming ATSC 3.0 video causes it to take several seconds to either tune a channel or to recover in the event of transient interference. The strange choice of ISOBMFF fMP4, a reliable delivery and storage format, over MPEG-TS, an unreliable delivery streaming format, means that synchronization can take several seconds in the event of even transient interference and upon every channel change, leading to a very poor user experience, especially for those living in areas of challenging reception conditions (as we do, living less than 5 miles from a major airport).

These decisions taken in aggregate give the impression that A3SA and NAB are entirely concerned about protecting their own interests and not at all concerned about serving the public over the public airwaves. To sunset ATSC 1.0 without addressing issues which affect the viewing public in ways unseen before in broadcast history would do them a great disservice.

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