Pileated Woodpecker At Work
Posted by Ed in Photography & Images on 2019-03-24
A loud rat-a-tat-a-tat drew our attention to a Pileated Woodpecker excavating a tree along Rt 376:
Pileated woodpeckers sculpt their holes with great care, often inspecting their work for smoothness and, perhaps, lunch:
Those holes go deep enough inside the tree to serve as shelters for smaller birds during storms.
We occasionally see and hear them, as well as their smaller relatives, remodeling trees around the house. Good hunting!
Taken with the Pixel XL zoomed all the way tight, cropped and sharpened a smidge.
Frozen Fire Hydrant
Spotted on a walk around the block:
Hydrant valves attach directly to the water main, far below the frost line, which means the hydrant itself should be dry when it’s not in use; the ice reveals a nasty valve leak. The corroded paint suggests a longstanding leak, but I admit to not noticing anything before now.
I uploaded the picture so I could include the URL in an email to the local fire department. I’ll take a look the next time we walk by to see what’s happened.
It’s definitely not a shapely hydrant!
Another WS2812 Failure: Broken Glass
Posted by Ed in Electronics Workbench, Machine Shop, Science on 2019-03-22
The WS2812 under the 5U4GB full-wave rectifier tube went into pinball panic mode:
It’s been running more-or-less continuously since late 2016, so call it
Because I’d be crazy to replace it with another likely-to-fail WS2812, I had to remove both of them before installing SK6812 RGBW LEDs and updating the Arduino Nano.
Unfortunately, I did a really good job of bonding the side light to the tube with epoxy:
The last tube manufacturing step involved flashing the getter onto the tube envelope, so as to remove the last vestige of air. Admitting air oxidizes the getter:
It was such a pretty tube, too …
Sony DSC-F717 Memory Stick Socket Cable Re-Rework
Posted by Ed in Electronics Workbench, Photography & Images on 2019-03-21
Once again, the Memory Stick socket cable in my trusty DSC-F717 camera became erratic, leading to continuous C:13:01 “format error” crashes, so I tore it apart. Proceed as before, until the camera carcass disgorges the socket:
Gently pry the metal cover outward to clear the latches along the sides:
The cover remains held in place by two tabs inside the holes on either side of the Memory Stick contacts, one of which is already free in the previous photo:
The small spring on the left ejects the Memory Stick and will, if suitably provoked, launch itself across the bench. Be prepared!
Use a pointy instrument to ease those tabs away from their latches and pop the top:
I cleaned the contacts, not that they appeared particularly filthy, gently bent them upward by three micro-smidgens to apply a bit more pressure to the card’s contacts, and reassembled the socket in reverse order.
I put a strip of Kapton tape on the back of the cable termination paddle (shown here during the previous repair) to ensure a snug fit:
Unfortunately, I snapped off a locking tab on one of the ribbon cable connections to the main board:
The cable threads through the middle of the clamp, which then slides into the socket and applies pressure to the contacts through the cable: no clamp, no pressure, no good.
For lack of anything smarter, I tamped the clamp into the socket and applied a strip of Kapton tape to maintain everything in more-or-less the right position:
Definitely unpretty, but better than nothing. While I was in there, I reinforced the other connections with similar clamps.
Reassemble the camera in reverse order and it’s all good:
It probably won’t last another decade, but ya never know …
Improved Shoelace Ferrule Aglets
Posted by Ed in Home Ec, Machine Shop on 2019-03-20
After considerable evaluation, the Customer decided the shoelaces were still too long and said the hex-crimped ferrules were entirely too rough and tended to snag on things. This time, I prepared the ferrules by chucking them in the lathe:
The steel rod inside the ferrule encourages it to remain round and not collapse while I’m filing off the flange that normally holds the plastic strain-relief doodad:
I snipped another half inch off each end of the laces and crimped on the prepared ferrules:
Which were definitely too jaggy, so they now sport an epoxy coat:
Alas, JB Kwik epoxy has a pot life measured in minutes, so the last ferrule looks a bit lumpy. They seem to work fine and the Customer is happy with the results.
Memo to Self: Next time, dunk the ferrules in a pot of slow-curing JB Weld and let them drain overnight.
ESR02 Test Clips
Posted by Ed in Electronics Workbench on 2019-03-19
An ANENG AN8009 multimeter recently arrived, complete with a bag of test probe parts, including a banana plug and an alligator clip crying out for a 3 mm threaded brass insert:
A pair of them fit neatly into an ESR02 tester, where they provide tidy a low-inductance / low-capacitance “test fixture”:
Admittedly, loading the part-under-test isn’t a one-handed operation, but it works reasonably well.
RD JDS6600 Signal Generator: Warmup Time
Posted by Ed in Electronics Workbench, Science on 2019-03-18
An RD JDS6600 Signal Generator recently arrived from around the curve of the horizon, leading me to measure its warmup time:
Looks like it’s good to go after maybe 90 minutes and, after much longer, it settles to 10 MHz +36 Hz, for a correction factor of 0.9999964 on those days when you’re being really fussy.
The need for frequencies accurate to better than 4 ppm doesn’t happen very often around here, but it’s best to be prepared. It’s amazing what you can get for under $100 these days …
I measured the frequency by zero-beating against the Z3801 GPS Frequency Standard (purple trace in the middle):
Basically, trigger the scope on either trace, crank the JDS6600 frequency in 1 Hz, then 0.1 Hz steps, until the traces stop crawling past each other, and you’re done.
It’s worth noting you (well, I) must crank eleven 0.01 Hz steps to change the output frequency by about 0.1 Hz around 10 MHz, suggesting the actual frequency steps are on the order of 0.1 Hz, no matter what the display resolution may lead you to think.
The RDS6600 main PCB (Rev 15) sports a 24 MHz oscillator close to the Lattice FPGA:
The AD9850 step size worked out to 0.0291 Hz for the LF crystal tester. A 24 MHz clock would produce a 5.7 mHz step size, but that’s obviously no what’s going on. More study is indicated.
The bottom trace is the scope’s internal function generator, also set to 10 MHz. Zero-beating the JDS6600 against the scope’s output produces a similar result:
The scope’s function generator actually runs at (9.999964 MHz) × (0.9999964) = 9.999928 MHz, a whopping 72 ppm low. The on-screen frequency measurements don’t have enough resolution to show the offset, nor to zero-beat it with the Z3801 input, so it’s as good as it needs to be.
The Z3801’s double-oven oscillator takes a few days to settle from a cold start, so this wasn’t an impulsive measurement. Having the power drop midway through the process didn’t help, either, but it’s March in the Northeast and one gets occasional blizzards with no additional charge.
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