Potentially Dangerous Mobile Antenna Failure – Could Happen to You!

Maybe this should be called operator failure, and not antenna failure, but there is an important lesson in it… please read on!

Corona Ball

I am an amateur radio operator (“Ham”) and as such I have several antennae mounted on my truck, and as is often the case with antenna design, each one has a round ball at the top of the antenna, as you can see in the picture to the right.

It’s actually got a name, and a purpose. It’s called a “Corona Ball”, and no, it’s not there to save you from poking your eye out–the actual purpose is to prevent the accumulation of coronal energy at the end of the antenna, which can be harmful to your radio. I believe such coronal discharge is related to the phenomenon known as St. Elmo’s Fire, but this article isn’t about coronae and some-such… read on!

Recently I was staying at a hotel in Toronto, and at one point I decided to park in the parking garage. One of the antennas on my truck is nearly 2M (6 feet) long and mounted on the top edge of the fender, so the tip is easily 3M (10 feet) from the ground, if not more. Normally when driving in a parking garage, I fold my antenna over by drawing the antenna into the passenger side window and raising the window to just catch the corona ball tip.

But on this particular occasion I was not feeling well and decided I would just let the antenna drag along the garage ceiling as I carefully drove into the garage. Well, that was a mistake! As I was driving into the parking garage, the corona ball rode along a bundle of wires, and was captured, with amazing tenacity, by the overhead wire bundle. In fact, the bundle got hold of the antenna so firmly it literals ripped the antenna from my truck, and did so quite violently!

10M Antenna – in Better Times
Death of a 10M Antenna

In the pictures, you can see what my antenna looked like in better times, and what it looks like today, the silver part having remained screwed to my truck, with the black part staying with the extricated antenna.

This rapid evisceration of my beloved 10M HF antenna made quite the loud BANG… but as I was only moving at about 2-3kph, less than walking pace, and because I had not noticed this as the source of the bang, I’d assumed I had either hit something, or I had been hit by something. I got out of the truck to do a walk-around, and as I rounded the passenger side first noticed the antenna was missing, and then I looked behind the truck and there was my antenna, a few metres back, appearing to be standing in mid-air, hanging from the ceiling wire bundle!

I walked back and grabbed the antenna, intending to remove it by walking it backwards to free it from the wire bundle. While this was perfectly effective, in retrospect, it was a very stupid thing to do! I was standing on the ground, holding a metal rod in my hand, a metal rod that had been forcefully wedged into an overhead wire bundle. Think about that for a second. Imagine if that wire bundle had contained mains wiring, and the antenna had torn the mains sheathing!

Thankfully, the garage I was in conformed to Canada’s building code, and therefore no high current wiring would be included in that bundle, at least not without some form of armour, but it’s still quite a lesson to me, at least in retrospect. Even if the wiring had contained low voltage, it’s not something I would want injected into my radio!

So the moral of the story is, if you do have tall antenna on your vehicle, you cool nerd you, you may wish to consider a clip or some other retaining method, such as the corona-ball-in-the-window trick, as a way to ensure your safety, your radios safety, your vehicles safety, and the safety of the overhead wiring in parking garages!

Until another time, 73’s!

My Security Camera “DIY”

So for the past little while someone has been stealing our mail… yes, our physical mail. I decided to handle this in the way I usually handle these sorts of things… I over engineered a non-solution.

So rather than simply get a locking mailbox, like my sensible neighbour, or even cutting a mail-slot in the door, I decided what I really needed was a security camera system.

After lots of research, I found some awesome free (for non-commercial use) camera software named Shinobi CCTV that will run on just about any common platform (*NIX, Windows, MacOS) and loaded that on my Linux box and attached a Web Camera. After some experimentation I got something working, but the camera was inside, and had a poor view of the front of the house, but as a proof of concept it was a pass! And as DIY goes, this is a win because most of the “D” has been done for me.

Next, I bought a Raspberry Pi from BuyaPi.ca, and tried that but it was less than ideal… the Pi just didn’t have the oomph to work with the camera… nearly 90% CPU with one camera, but it was not the Pi’s fault… I was doing video conversion, video noise suppression, and zoned motion detection, on a Pi… which was never designed to do that much heavy lifting. I either needed a more powerful platform, or a camera that did much of the processing itself before even handing it to the Pi.

After some more research, I bought a “real” security camera, a HoSafe H2MB6A for just $65CAD delivered overnight from Amazon! It allowed me to use hardware acceleration on the Pi, and CPU usage dropped into the teens even with motion detection being done by the Pi! Woot!

After some testing, I was very happy that the system would work. so I ordered a second camera, and today I installed them both… one on my side of our duplex, facing East, and one on my intelligent* neighbours duplex, facing West. Just a few hours and it was working! It still needs some tidying up (the wiring is exposed, for now) but it’s running, and should catch my mail thief any year now.

I have been tweaking the settings since installation, but am very pleased. One of the things I am really impressed with is the low light performance of these cameras… in fact, you can see a video of the test here on YouTube.

Anyway, that’s it for now… with any luck I will post some more interesting things I “catch” on this system… wish me luck catching my mail thief.

*He’s intelligent because not only does he have a locking mailbox, but his neighbour ended up installing a security camera system so he doesn’t really have to.

Jamie’s Instant Pot Baby Back Ribs

This one was inspired by and partially plagiarized from a bunch of recipes on the Internet! Let’s call that research.

Ingredients

  • Cajun spice – as a rub
  • 1/4 cup Canadian Rye Whiskey – this is optional and I have not tried it without it yet to see if it makes much of a difference. If you do try it without I would love to get your feedback
  • 1 cup BBQ sauce – choose bold flavour – I use original recipe Bulls Eye
  • 2 cups Coca Cola (or your favourite cola beverage)

Preparation

  • Rinse ribs under cold tap water to remove any bone chips, etc.
  • Pat dry.
  • Some butchers remove the membrane when selling ribs. If yours still have the membrane on, don’t worry, it’s easy to remove:
    • At the smaller end, of the rack slide the tip of a knife under the membrane, next to the bone.
    • Lift membrane until it separates from meat. Put down the knife. PUT. DOWN. THAT. KNIFE!
    • Grip edge of the membrane with a paper towel and pull up, then pull back toward larger end of rack.
  • Cut ribs in half or thirds to aid removal from pot afterward. Or you can tip ribs out into stainless steel bowl and leave as full racks.
  • Rub cajun spice onto both sides of ribs 
  • Add wet ingredients to pot, being sure to stir well
  • Add trivet to pot, Trivet will almost be submerged
  • Place ribs in pot, curved with “top” side toward the curvature of pot, curved inward with membrane side towards the middle of the pot. This is the way the ribs naturally curl. If you chose to leave ribs un-cut you should be able to put two racks in. If you have three, you will probably have to cut the third one. This is based on 6lbs being three racks. 6lbs seems to be the limit of the 6 quart Instant Pot.
  • Meat button, or manual button, Normal, High Pressure for 30 minutes for 5-6lbs of ribs; 25 minutes for 2-4lbs
  • Natural release 15 minutes.
  • During the natural release:
    • Put oven shelf on second highest rack, unless that’s your middle position, in which case choose the top height.
    • Pre-heat broiler
    • Prepare a foil lined large cookie sheet
  • Transfer ribs to foil lined cookie sheet. Careful, they will be fall-off-the-bone tender so they will fall apart if mishandled
  • Brush with your favourite BBQ sauce
  • Place ribs under broiler, 5-10 minutes.  Watch them closely after 5 minutes so they don’t burn.
Enjoy!