If I recall correctly, the change from x-cycles to x-hertz occurred in 1960 in memory of Heinrich Rudolf Hertz, the German physicist who did much research in electromagnetism.
However, I can distinctly recall that while serving on USS Saratoga (CVA-60), back in 1968, that in the Metrology/Calibration field we were still employing the term ‘cycles,’ until a directive was issued to standardize to ‘hertz.’

While much of the world was in the process changing over, we (the USN) were getting new equipment with ID plates specifiying frequency in cycles (megacycles, kilomegacycles, etc.).
And it took a bit before all tech manuals were standardized to the new format.

In any case, I understand your relative resistance, because I too, had been trained to employ the term ‘cycles,’ starting in 1955, and back then every radio was labeled with such on its frequency dial.

With regards to the current frequencies in use, this web site discusses it’s garage door frequency bands;

Just wondering

Derf

We have deer, wild turkeys by the dozens here on our place and we treat them all as pets. When they go out on the roads the poachers blow them away. That’s not my problem. I don’t care for it but factually, it’s none of my business.
In the spring and summer the turkeys come up near our dwelling and observe our cats. They stare at them and I suppose wonder what they are. We hear them outside making their sounds, Pert,Pert,Pert. It’s a very mellow but penetrating sound. I think they too would like to be living with us.

Being that this is the country and I get up with the chickens it’s now time for me to hit the sack.

Quote:
“The last spectrum analyzer I used was an HP, don’t remember the model, but it wa a very good one. I was on the job of course in Irvine, California. Thats more than twenty five years ago.”
Unquote.

That likely was a Model 141T.
See this:

When I was in the USN, I worked in Metrology/Calibration. That was the very best field to be in, because you got to work on everything instead of specializing on just one or two systems. Heck, I even repaired the occasional optical borescope, and several night vision devices!

I can’t begin to tell you how many spectrum analyzers – of whatever make and model – I repaired and calbrated.
The very first one I got to work on was an SA80, and it was heavy enough that it required two men to move it, and even then it was difficult.

And yes, cameras! You might be advised though that there are detectors out there, and one of the best is this:

There is a philosophy regarding having both visible and hidden cameras, versus just one or the other. What you can’t see, you can’t know about; what you can see makes you aware. Most burglars are petty people, and afraid of being caught. Seeing an obvious camera sends them packing.
It’s like having a radio turned on and playing: Is someone home, or not? If you can’t see in, then you are blind to the fact.

Now, let me relate to you an incident that happened to me about a year ago.
One day, a car backed into my driveway from the cul-de-sac (this is unusual in itself, as who backs into a 150 foot driveway?), two young men (early 20′s – if that)
got out of the car, and one of them stood by the garage door in plain sight of the front door, while the other went around to the east side of the garage, and upon seeing one of the cameras, spray-painted the window at the farthest (quickly visible) camera and then saw the nearest camera (the one closest to him) and took off running back to the car, whereupon they quickly drove away. They haven’t been back since.

Window cameras should always be placed aiming in the direction of the opposite camera to get a cross field view such that the approach covers both directions and the near field at the same time.

And a decal on window that says ‘This house protected by Smith & Wesson’ doesn’t hurt either!

Any strange vehicle that backs into a driveway is the first telltale sign of something amiss.

Now, I called the cops, but they never came by, and didn’t even want to talk about the video clips from the few cameras that caught their actions.
Apparently, someone entering upon your property and spray painting windows is considered such a paltry offence, that it’s not even worth investigating.

Sometime ago, I purchased a Day-Night surveillance camera that advertised as having IR illumination, however the bugger used 800nm range LEDs, and those are visible. So, I went an found some 700nm range (not visible) LEDs, and swapped them out.
It works even better, as there is all the more IR is being generated where it needs to be, rather than in the visible light spectrum.

Now, all of this really good, but if there is prowler out and about who’s wearing a ski mask, the cameras won’t do much, and alarms that don’t awaken neighbors are less than useless.
I given thought to a project that uses millimeter radiation (close to the range used by airport security to see under clothing) in order to see past the mask. Most of the tech is off-the-shelf stuff.
And then there is the thought of using something in the ultrasonic range …

My particular system used a two-level alert: First an internal warning is generated, with a less than one minute delay before the outside alarms get activated. This delay gives me time reset the alarm, and check out the situation if I’m home.

I’ve had a few false alarms caused by animals, and being woken from a dead sleep is as about as frightening a thing as any! It’s good drill though, for it helps prepare you for the real thing. The first time you get woken, you’re a bundle of nerves shaking almost uncontrollably!
But then the old miltary training kicks in, and you develop an almost automatic protocol of preparation.

The last spectrum analyzer I used was an HP, don’t remember the model, but it wa a very good one. I was on the job of course in Irvine, California. Thats more than twenty five years ago.

I’ve got some fair pieces of equipment, old, but they work. Nothing in the high frequency area though.

Actually, if somebody opened my garage door in any manner they’d find a tractor, some garden tools and my old Yamaha bike. That’s because it’s in a barn. All insured of course.

Iv’e also got a modern video alarm system with several cameras in hidden places. Much better than a dog barking all the time. When the alarm goes off the recorder starts to record. It works well both day and night. I never have an unannounced guest.

One thing about people like us is that we work with electronics because we like it. And when we are no longer employed we still like to tinker, that’s me.

Wife is calling me to dinner

Good points all around.
However …

What with computer hackers (the bad kind) seeking to access every machine they might – and very often succeeding – one should not make any assumption regarding who else might not possess sufficient knowledge of the design of one’s security system.
Remember: If you can think about it, likely someone else has also.

When I consider security systems (I possess a fair level of knowlege of the field), the thing I think of most is: WHAT IF?

I will hand it to you that you’re likely correct in that no one else in your vicinity – today – would possess the knowledge of your final design.
But, consider the others that read our words here.
Technology doesn’t stand still, and you already knew that.

Spectrum analyzers (of whatever sort) and data analyzers are becoming rather inexpensive on the second hand market. Go check ebay for good examples!
When you and I were kids, the simplest of test equipment cost darned near an arm and a leg. I still have an old Archer vacuum tube based VOM, from back in the early 1960′s, and a Heathkit spectrum analyzer (built from a kit – 1965), both of which I worked months to save up for!
Today, those items are considered useless junk – but they still work.

I mention this for the reason that there are some really smart, really savvy, and really crooked kids on the block these days. Nothing pleases them more than to get over on other people. I don’t know why that is, as such a psychology certainly didn’t exist when I was a kid, at least not where I grew up.

And finally, I also understand that if someone really =really= wants access to your house bad enough, a garage door won’t even stop them.
Bottom line: The happy medium is to make the lock as ‘unpickable’ as possible.