Friday, 30 June 2017

09:22 – It was 65.4F (18.5C) when I took Colin out at 0620, overcast and drizzling. Barbara got back from dinner with her friend Marcy about 2100. The local ham radio club net runs at 2030 Thursday evenings. I could hear the repeater loud and clear, but it couldn’t hear me, either with the standard UV-82 rubber duck antenna or with the Nagoya NA771 whip. I need to do some work on that.

Frances and Al are stopping by this afternoon. They’re bringing along their Linux desktop system, which I haven’t looked at for probably three or four years. I had it set to autoupdate, but even so it needs a thorough going-over. IIRC, it’s running Linux Mint, but I’m not even sure about that.

I’ll get it set up, probably in the den, and then pull backups to two different external hard drives, and data backups to a couple of DVD-R discs as well. Once I’m sure I have good backups, I’ll do a deep hard drive test and then blow away what’s on there and install the current Linux Mint LTS version and get all of their plugins and software updated.

I’m not too concerned about the hard drives. Spinning disks have failure curves pretty much like incandescent light bulbs–pretty much a Poisson Distribution, with some very early failures, followed by what looks almost like a Normal Distribution for the next few years, followed by a long-tail curve.

Speaking of failures, we had an electronic scale fail yesterday. Barbara was filling agar bottles, weighing each to ensure they got at least the specified 10 grams each. I’d just bought agar from a new source, so I ordered only half a kilo until I could look at it. Nominally, she should have gotten 50 bottles from that 500 g of agar, but she always goes slightly over, so I told her she might get 45 or 47 bottles.

She came to get me a while later and showed me that she already had 45 bottles filled, but still had almost half the original agar left. So I went in and got a spare scale. It turned out she’d been transferring only about 6 grams to each bottle, even though the scale was indicating 10+ grams each. So I pitched the old scale in the trash and immediately ordered two more spares. While I was at it, I ordered another 500 grams of agar.

It’d been a while since I calibrated the bad scale with a standard set of weights. I probably need to put a reminder on my calendar to do that periodically.

Email from Jen. They tried their new NV camera system I mentioned yesterday with and without the supplemental IR LED illuminator. She said it helped some, but it was difficult to tell just how much. Like just about any location east of the Mississippi, Jen and David’s home suffers from some light pollution. They’re rural, but there are enough lights around that there’s some sky glow, which is apparently sufficient to let the low-light capability of their cameras function.

They’re rated at a 100-foot detection range at 0.00 lux, using the built-in IR LED illuminators, but even without the IR they’re supposedly good down to something like 0.01 lux. They waited until full dark and then sent the nephews out to walk around the yard. They were wearing reasonably dark clothing–jeans and such–and they were able to detect movement out well past 100 feet. Turning on the supplemental IR LED illuminator brightened things up a bit, but they really couldn’t tell just how far they’d be able to spot movement with just the built-in IR versus with the supplemental illuminator also lit.