Homer

The “halibut capital of the world”, so claims this city at the very end of the Kenai peninsula.

And beyond the end of the peninsula runs a 5-mile “spit” into the bay that hosts marinas with commercial and tourist fishing, restaurants, art galleries and at the very end, the “Land’s End” hotel, where we stayed for a night, entranced by the scenery surrounding us.

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Seward

Beautiful scenery on the road to Seward.

On a brisk sunny day we drove from Alyeska to Seward– one of the most beautiful drives I have ever taken— through snow-covered mountains in the low-angle beauty light of the Alaskan morning sun.  I wish I had stopped and taken more photos.

We had a scenic boat tour scheduled, a large boat with three viewing decks.  The nice weather made for a very pleasant outing, albeit sometimes cold and windy, especially as we left the protection of Resurrection Bay into the open Pacific Ocean.

Even though Seward is a small fishing and (in the summer) tourist town, there is a large center devoted to local sea life, where after a lifetime of wanting to see them, Poldi encountered puffins!

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Alyeska

I learned to ski late, in my thirties, but I was able to become skilled enough to enjoy the long runs at the mountainous ski areas of Utah, Colorado, Idaho and Montana.  My skills have atrophied as my skiing opportunities have diminished in recent years, so I was quite excited that a visit to Alyeska ski resort was in our plans.

Alyeska Peak is not as high as those in the Rockies, but the elevation at the bottom is essentially sea level, so one is treated to a large vertical drop without the high nosebleed risk (and out-of-breathness) of high elevations.

Poldi’s sister April joined us at this juncture of our Alaska trip.  She was once a world-class competitive skier, who early in her career came to Alyeska to compete.  One of her ski team friends, Heather, eventually came here permanently, raised a family and is still actively teaching.  I became her informal ski student as we explored the slopes of Alyeska. Here are some photos.

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Talkeetna

A town of about 1000 people, its population increases dramatically with tourists in the summer.  Its mayor is a cat named “Denali”.  At the beginning of Spring, the snow is still deep, requiring waist-high trenches to reach the decks of our cabins.  The highlight of our time in Talkeetna was a visit to a sled dog training center, the endeavor of the locally famous musher and Iditarod winner, Dallas Seavey.  There were 130 dogs under the supervision of 6 to 8 trainers.  In addition to their wrangling, feeding and scooping chores, the trainers host tourists, setting them up to ride a dogsled on one of their training courses.  This actually provides a training service for the dogs—giving them practice at maintaining a target speed and keeping a fixed pace.

Tourists are also used to socialize the dogs, starting with puppies.  We were encouraged to pet them and play with them; see the photos below.

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Denali

We travelled by van to Talkeetna, the gateway of Denali National Park, passing through spectacular mountain vistas.  By accident, I learned that there were vacancies on a sight-seeing small-plane tour into the park, and on a last-minute realization that the skies were clear and I would not likely be here again any time soon, I booked the flight!  It was an amazing experience.  Here are a few photos and a video sample.

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Chena Hot Springs

Two hours northeast of Fairbanks is a feature that is the focal point of a rustic resort, Chena Hot Springs.  The resort has been augmented by a geothermal power plant, greenhouses, and tourist attractions including the “Ice Museum”.  We spent an afternoon visiting, ending with a soak in an outdoor pool fed by the springs.

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Relay Resurrection

The restored relay clock, in its original glass case

I have renovated the components of my nearly 50-year-old digital clock. The next step was to assemble it all back together. Would it actually work?

The old broken and abused internal plexiglass chassis was replaced by new plexiglass, providing an opportunity for me to learn the technique of plastic welding, where a syringe injects solvent into the edge of a surface-to-surface joint and spreads by capillary action to the full contact area, partially dissolving the plexiglass, which then forms new polymer bonds between the pieces. It takes a few minutes for it to start hardening, which gives some time to prop the parts in the desired position (use a square to get the angles right). It is completely cured in 24 hours and is truly “welded”. Like a good metal weld, a good plastic weld will break elsewhere if enough force is applied.

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The Relay Clock Display

Digital readouts, probably from an aviation display

I recall seeing displays similar to this in elevators when I was very young, but it appears that these digital readouts came from a cockpit display or some other instrument. It seems rather impractical to me today, but digital displays were difficult to make back then, especially for the rugged environments found in aviation. I found a display similar to this being offered at a surplus site.

A front and rear view of a surplus aircraft readout. There was only one available, at a price of $150!


The basic idea is that there are ten light bulbs for each display digit. One of them is energized and lights up. It projects a numeric image onto a screen.

In this clock, the relay contacts direct a voltage to select a display digit. The relay coils operate at voltages of 12V, 24V, and 110V, but the display uses light bulbs that run at 6.3V, a common voltage used for vacuum tube filaments and pinball machine lights. You can see why 6.3 was a popular voltage, right?

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Wiring

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The back end of two three-digit display modules. On the right, the bundled cable wiring has been replaced by flat ribbon cable with insulation displacement connectors. The remnants of the old ribbon cable from the relays are seen on the left, individually soldered to the display lamp wires.

I had planned to replace the inadequately designed power supply for the clock, and I had figured out how to update the signals to the relay coils, but I had really hoped that I could avoid re-wiring all of the individual connections between the relay contacts and the display bulbs (10 + 6 + 10 + 6 + 10 + 2 of them).  I had figured out the connections and how they could be used with the new power supply without having to completely rewire them.

In 1973 I was using some of the latest technology, including “ribbon cable”, an evolutionary step from a tied cable bundle.  Individual wires were laid side-by-side and cast in place with an insulating plastic bond.  They were also called flat cables.  Once again, my source of this unusual wiring system was from my dad’s ham radio shack. 

I found them particularly appealing because they were color-coded with the series used to identify resistor values-  black, brown, red, orange, yellow, green, blue, violet, gray, white to represent digits 0, 1, 2, … 9.  They include the colors of the rainbow, and I recall thinking how nice they will look in the finished clock, which motivated me as I connected them to the stepper relays. 

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Early Integrated Circuits

Two 7490 integrated circuits. The date code tells us that they were manufactured in September of 1972.

Although I was unaware of the new integrated voltage regulator circuits when I built this clock, I was familiar with an early series of integrated logic circuits, the 74xx TTL chips (TTL stands for “transistor-transistor-logic”). Again, the ability to replace multiple circuit boards of discrete components that implemented a specific logic function with a single integrated circuit chip, was revolutionizing electronics.

An example is the 7490, a small 14-pin device that implemented logic that could count to ten. I used two of them, configured to count to 60 and then start over. I fed it a clock input that was derived from the household AC line, 60 cycles per second, and it delivered a logic pulse once a second to the first relay in the clock.

I wanted to keep this relic of a circuit in the renovated clock, and so I adapted its input to the AC signal from the new power supply. But I had forgotten the rules for using the ancient TTL logic, which required much higher current than is used today. Modern CMOS logic uses almost zero electrons to do their magic, which is why your phone doesn’t discharge within a few minutes, blistering your hand with the heat.

My first attempt to trigger the old timekeeping logic resulted in paralysis. No ticks.

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