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A bin of slide rules

One of the finds from the 2022 Atlanta Hamfest that I’m most excited about is the bin of slide rules and slide rule books that Connie found at one of the flea market tables.

A bin of assorted slide rules and slide rule books
A bin of slide rules and slide rule books

There were 10 different slide rules and a total of 12 slide rules in the bin. Some of them were pretty basic slide rules, and some were more advanced with multiple scales, some of which I hadn’t seen before. These bring my slide rule collection up to 15.

I’ve made a first pass through the bin to check out the slide rules and jot down some notes about them. All of them are in pretty good condition, although one of them is missing the cursor. Two Keuffel & Esser rules, three Picketts, three Sterling, a couple very short pocket sized slide rules, and a little circular rule with some basic scales on it.

It will take me a while to research, photograph, and learn more about each slide rule. Should be a fun project.

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Pixel 6 X-ray

A radiograph of my new Pixel 6 phone. The Pixel 6 is a big chunky phone with a lot of stuff in it.

X-ray image of a Pixel 6 smartphone
X-ray image of a Pixel 6 smartphone. 80 kV, 1 mAs

This one was acquired using a portable x-ray unit at 80 kV, 1 mAs, and the small focal spot. It’s raised up about 25 cm above the image receptor for a bit of magnification (about 1.3x) and cropped in from the original image.

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SpaceX, Starlink, and planets

Managed to catch the SpaceX launch of more Starlink satellites this morning.

Also participating in the show were four planets in the early morning sky: Venus, Jupiter, Mars, and Saturn.

Four planets in the sky. From lower left to upper right: Venus, Jupiter, Mars, and Saturn
Four planets in the sky. From lower left to upper right: Venus, Jupiter, Mars, and Saturn

A couple minutes or so after the launch, we spotted the Falcon 9 plume.

SpaceX Falcon 9 exhaust plume visible over some houses in the foreground.
SpaceX Falcon 9 exhaust plume

This was shortly after the second stage separation and fairing separation. The two small specks of light close to each other are the two fairing halves. The third speck of light just behind and below the other two is the booster stage on its way back to the barge off the South Carolina coast. The speck of light above the rocket plume is Mars.

Falcon 9 rocket plume. Faintly visible are the two fairing halves and the first stage booster. Mars is in the background above the plume.
Falcon 9 rocket plume. Faintly visible are the two fairing halves and the first stage booster. Mars is in the background above the plume.

This shows the fairing halves and first stage booster a little better (lower right). Also visible are Venus and Jupiter in the lower left of the image. The larger blob of light above and to the left of the second stage rocket is just internal reflection of a street light across the street.

Falcon 9 second stage rocket. Visible in the lower right are the two fairing halves and the first stage booster. Venus and Jupiter are toward the lower left.
Falcon 9 second stage rocket. Visible in the lower right are the two fairing halves and the first stage booster. Venus and Jupiter are toward the lower left.

Always neat to see a rocket streaking by.

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Soldering station upgrade

I’m finally upgrading my soldering station.

After many years of using my slow, inexpensive (but pretty reliable) Radio Shack soldering iron, I’m upgrading to a Hakko FX-888D!

Hakko FX-888D soldering station
Hakko FX-888D soldering station

I’m excited to start using the Hakko. I expect there will be a bit of a learning curve with the new soldering iron, but I think it will be a nice step up. The old soldering iron will go back to the garage to get used on projects there.

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RCA Victor 45-EY-3 vintage record player

On the workbench for some troubleshooting is a 1950s era vintage RCA Victor 45-EY-3 record player. It belongs to someone in my neighbourhood and came to me via a referral from a neighbour who’s familiar with my penchant for tinkering with electronics.

RCA Victor 45-EY-3 record player from 1950
RCA Victor 45-EY-3 record player from 1950
RCA Victor 45-EY-3 record player from 1950
RCA Victor 45-EY-3 record player from 1950
RCA Victor 45-EY-3 record player from 1950
RCA Victor 45-EY-3 record player from 1950

The owner purchased this recently and had already replaced the tubes, capacitors, a few resistors and some of the mechanical bits before the record player landed on my bench. He said it was sort of working (some mechanical issues with the arm moving), but then stopped turning on. Fortunately, he had a printouts of the service documentation available to look over. On the electronics side, the circuitry is pretty simple consisting of three tubes: rectifier (35W4), amplifier (12AV6), and output (50C5).

RCA Victor 45-EY-3 schematic
RCA Victor 45-EY-3 schematic

After touching up a few solder joints, I found the power switch was kind of dodgy and would work if I tilted it a certain way. I also realigned the muting switch (S2) so that it was oriented the same way as one of the photos in the service manual. That got me to the point where records could play and sound came out of the speaker instead of just resonating through the needle arm. The sound volume was pretty low though, even with the volume pot turned up all the way and there’s also a lot of hum getting into the electronics too. Those are the two main things I need to work on, and the owner will work on the mechanical stuff.