Sending my name off to Mars again, this time withe the Mars 2020 Rover.
One of the exposure meters in my collection (a Radcal/MDH 1515) uses this Eveready #493 300V battery as bias voltage source for the ionization chamber used to measure x-ray exposure. The rest of the meter is powered by 4x2V rechargable lead acid batteries in a D cell form factor.
Looks like this battery was installed in December 2002. Last calibration date for the meter was 2003, so it was probably replaced when it was sent in for the previous calibration.
After 16 years of sitting on the shelf, the battery is pretty flat.
Let’s take the cardboard off and have a look at what’s inside.
There are 10 plastic wrapped packs, each 1.3 cm x 2.2 cm x 6.6 cm long, all connected in series. Each pack appears to have 20 individual cells coated in a waxy type material and wrapped in plastic to hold them all together. With 200 cells, that gives 1.5 V for each cell.
Looks like there’s been a bit of leakage while the battery sat on the shelf for the past 16 years.
A close up of one of the packs.
I’m starting to accumulate a bit of a power supply collection now, it seems.
Haven’t looked inside it yet, but I did plug it in and turn it on. Made the satisfying “thunk” of a big linear transformer being energized, and the 6.3 VAC terminals were putting out about 6.5 VAC (unloaded), which seemed reasonable.
A quick look around the Internets yields hits on various audio forms, so seems like a popular piece of gear in those circles.
While I was scoping out the electronics, Connie was over in the books and found a copy of Practical Antenna Handbook by Joseph Carr, so that went into the cart as well. No such thing as too many antenna books, right?
Good shopping day at the thrift store today.
This is how it begins, right? You’re in one of your favourite thrift stores just browsing around one day, and you spot this sweet looking piece of gear just sitting there on the shelf. It’s really cool looking. Your brain (and your wife) goes “Dude, get it”. Nevermind that you don’t know the first thing about audio except that it’s something your ears detect.
So now I’m the owner of what appears to be a double sided, very slick looking audio amp.
It’s a pretty hefty unit. The only labels on the amp are the DSM logo and a name plate saying who the amp was made for.
All the tubes emited a nice soothing warm reddish glow when I plugged the unit in and turned it on. Guessing that’s probably a good sign.
After thinking about it for a bit, I’m realizing that each side of the amp corresponds to the left and right channel coming from each device going into the unit.
I don’t know who William H. Moody is, and it’s unlikely I’ll ever find out. Whoever he was though, he probably liked his audio.
Noticed some new hops flowers on the vines at the hops tower as I was walking by this afternoon.