The View Up Here

Random scribblings about kites, photography, machining, and anything else

Archive for the ‘Uncategorized’ Category

Vacuum Chamber Camera Mounts

Posted by Tom Benedict on 26/07/2017

August 1st we’re taking our telescope apart so we can re-coat the mirror. To date I’ve helped coat mirrors from four telescopes on the mountain including those from CFHT (M1 and M2), Gemini North (M2), IRTF (M1), and UKIRT (M1). Later this year we’re coating the 2m M1 from the Las Cumbres Observatory Global Telescope Network’s Faulkes telescope on Maui. Next year (we think) we’ll add a fifth Big Island telescope to the list when we coat the M1, and two M2 mirrors from the University of Hawaii 88″.

All of these are done in the basement of the CFHT Observatory, my home away from home.

CFHT Aluminizing Room

Mirror coatings offer a unique opportunity to photograph a really cool process: going from a bare piece of glass to a mirror in under 60 seconds. The only problem? The coating chamber itself is one huge, opaque piece of steel.

The Chamber

Luckily, the chamber has two windows installed in it. One lets you view the mirror. The other lets you view the filaments that evaporate the aluminum onto the glass. They’re relatively small, with a clear aperture of seven inches, but with some careful arrangement it’s possible to position cameras to peer through them and photograph the flash.

But it’s not easy. In years past I’ve balanced tripods on relatively small platforms, bolted makeshift 80/20 frames above and below the windows to try to support cameras, and even resorted to using tape. At times my solutions have been downright ugly, but they’ve worked well enough to let me photograph the transition from glass to mirror.

Before and After - Telescope Mirror

This year I wised up. I asked my boss if I could spend a little money and solve this problem once and for all. “Sure,” was his reply. That one word solved everything.

The windows are held in place by a ten inch diameter ring and six 3/8″ bolts. I couldn’t modify the rings, but I could install longer bolts and add tabs that let me attach additional hardware.

With the tabs in place I was able to install four 11″ articulated arms that I ordered from Amazon (two per window). If I had the option I’d install more, but even with two the windows become crowded quickly.

Because the two windows offer such different views of the chamber, the photographic requirements differ as well:

The window on the top of the chamber – the one that offers the view of the filaments – is used for diagnostics: Did all of the filaments fire? Did the aluminum wick onto the filaments without dropping? Did the aluminum vaporize without spatter? These require a relatively wide angle view, so I mounted a GoPro on one of the arms. On the other I mounted a Pulnix low-light video camera that’s wired into a monitor down at the controls to the coating chamber.

Cameras on the top porthole

Because outside light will reflect off the chamber window, causing glare, when we’re using the cameras we have to keep them covered.

Top porthole black-bagged

The window on the side of the chamber – the one that offers a view of the mirror being coated – is used to observe the coating process. Was there arcing during the glow discharge stage? Did the glow discharge generate a usable plasma? Did all of the filaments fire? Did the glass get a coating of aluminum?

This window is a little more complicated. To observe the glow discharge and the filaments, we installed a convex mirror at the base of the window. A Gopro aimed at this mirror can see, albeit in a very distorted way, most of the filaments and almost all of the glow discharge cathode. To observe the mirror, I used a DSLR with an 11mm lens pressed flat against the window.

Cameras on the side porthole

The side window also needs to be protected from stray room light, and will be black-bagged the same way the upper window was. Before the next coating I’d like to make proper blackout bags to cover the windows, but for now the cloth-and-bungee method will work fine.

This year I hope we get some really excellent video and stills of our mirror coating without having to resort to duct tape and bailing wire!

Posted in Uncategorized | Leave a Comment »

Camouflage, Paint, and Hiding in Plain Sight

Posted by Tom Benedict on 12/06/2017

I’m planning on using my weatherproof recording box to record wind in the rocks and grass at a remote lake up on a mountain, weather permitting. (Weather not permitting, I’ll record something else!) But the place I’m planning to record is primarily browns and reds rather than the greens I used to camouflage my weatherproof gear. It’s too late to change my gear now, but in the future I’ll need to think more about the camouflage I use to hide my stuff in plain sight.

Meanwhile an interesting discussion about camouflage took place on one of the field recording discussion groups on Facebook. In the discussion, someone raised the point that paints, fabrics, etc. that look fine to us in the spectrum we can see may be overly visible or downright jarring in the spectrum visible to some wildlife. The discussion centered around deer, which can see into the UV, but also applies to birds, insects, etc.

Since I’m already in the business of characterizing the reflected spectra of materials, surface treatments, paints, etc. I scanned the paints under discussion to see what their reflected spectra look like. I prepped the samples the same way I did for the SPIE paper: four coats, applied at roughly a 45 degree angle, coming in from the four cardinal directions.

Krylon Paint Reflectivity 250nm - 750nm

All of these are from the Krylon Ultra Flat Camo Paint series, one of which, their flat black, was part of the sample set I scanned for the paper I presented at the 2016 SPIE Astronomical Telescopes and Instrumentation conference in Edinburgh.

From 250nm to 750nm things look relatively normal. The behavior short of 350nm is more a function of the binders than the pigments, and all are relatively similar to the flat black, some even performing a little better in the near-UV.

From 350nm out to 650nm you see the action of the pigments in each of the paints. Khaki is fairly broad-spectrum, reflecting a good amount of reds, greens and blues, tending toward the redder end of the spectrum. The brown (which is quite dark) peaks in the red, with lower reflectivity in the greens and blues. The olive and light green peak at shorter wavelengths, favoring more greens than reds. It all makes sense until you look at the near-infrared.

Krylon Paint Reflectivity 250nm - 2500nm

That’s where it gets really weird. The Krylon flat black paints use carbon as a pigment, so they tend to stay low well into the NIR. The long tails on the brown, olive, and khaki paints aren’t surprising, especially given what I saw with some of the other samples I measured for the SPIE paper.

What’s weird is the light green paint. It’s more reflective in the NIR than any of the other pigments in the visible. I have no idea what they use for a pigment, but it’s got one heckuva NIR signature.

None of which may matter much when it comes to camouflage. Photosynthesizing vegetation is quite reflective in the NIR, so having one out of five colors reflect strongly at NIR wavelengths may actually help the disguised object blend better in plant settings.

In reading further about deer and their ability to see into the near-UV, I learned that there are two things at work: First, deer really can see further into the UV than we can. In the case of reindeer it helps them find the lichens that are one of their primary food sources and it helps deer spot UV-absorbing urine markers from predators.

The other factor at work is that the sensitivity of the blue receptors in deer eyes peak around 400nm, right around the center wavelength at which fabric and paper brighteners fluoresce when exposed to UV light. It’s this effect that makes white cotton shirts, shoestrings, and paper glow under black light.

The Shimadzu spectrophotometer I use to measure samples registers light of any wavelength, so it’s sensitive to fluorescence as well as directly reflected light. But just to be on the safe side I photographed the paint samples under UV illumination, as well as with an IR-converted camera, the same one I used for the SPIE paper.

Paint Three Ways

All in all, I think the Krylon Ultra Flat Camo paints are good to use as camouflage, both for humans and for wildlife. But I need to come up with a better color combination for blending with lava rock than the green scheme I’ve currently got on my gear.

Posted in Uncategorized | 4 Comments »

Weatherproof Recording Box – Part 2

Posted by Tom Benedict on 02/06/2017

A little while back I wrote about a weatherproof recording box I’d built so that I could do drop-and-recover field recording without having to care quite so much about the weather. The design had a couple of shortcomings, most of which I’ve been able to address. Since then I had the chance to take the revised box out into the field and put it through its paces. I’m happy with how it performed.

The two biggest issues I had with the first revision of the box were the heating problem I mentioned at the tail end of that article and the fact that with the connectors I was using, I couldn’t actually plug all four channels into my recorder and still have it fit in the box. I had a couple of minor issues as well, including the fact that the lid on the weatherproof outlet cover rattles. Here are all the changes I made to address these problems:

I fixed the rattle in the outlet cover with small snippets of weatherstripping. Nothing fancy, just adding enough spring to take out any tendency to rattle in the wind.

I also added strips of industrial strength Velcro to either side of the box. This makes it easy to use the box as a baffle and mount omnis on either side like tree ears. I’m not entirely happy with how this sounds, though, since the box represents a much harder boundary than tree bark does.

The way I solved the connector issue was to swap out all the Neutrik XLR plugs for low profile connectors from Cable Techniques. Redco Audio sells these for about $15US. They come with black caps, but Cable Techniques makes color caps for the connectors as well, so I was able to maintain the color coordination between the outside panel and the inside connectors.

Low Profile Plugs

While I was at it I bought a right-angle USB cable for the battery pack. In 20/20 hindsight I wish I’d bought one with a right angle connector at both ends instead of just at the micro-USB end. But at this point it’s just a nit-pick. The cable I got works fine.

Right Angle USB

With those two changes, everything now fits in the box with all the foam panels installed.

Everything Fits

Which brings me to the second major modification: In an edit to the last article I said that I’d tested everything with a temperature logger, and in a 21C room the air temperature inside the box had risen to 34C after eight hours of operation. What I didn’t take into account is that the battery and recorder were considerably warmer than the air in the box. The operating range on my DR-70D is 0C-40C. I wasn’t comfortable running it that close to the limit.

Thermal Pad
The foam panels in the box are all removable. They just wedge into place. So I pulled the two side panels and installed thermal pads. Thermal pads are made out of silicone that’s had thermally conductive additives mixed in. They’re graded by their rate of heat transfer. The pads I bought have a decent transfer rate, but aren’t up into exotic territory. (I got mine off of Amazon.) As it turns out they’re probably overkill for the job, but I’d rather err on the side of too cool than not cool enough.

Everything Heat Sinked

With both pads installed and everything loaded into the box, a small block of closed cell foam acts like a spring to keep the battery and the recorder pressed up against their respective pads.

Weatherproof Recording Box in the Field

Last weekend I took it out to an old cane haul road on the Hamakua Coast to record coqui frogs. Unfortunately the road was blocked off about a mile from where I wanted to record, so I had to set in a different location along the road. It looks like logging operations are about to start out there, so this may be the last time I get to record at that location. (The box is weatherproof, but it won’t stop a bulldozer!)

I had some issues with moisture causing noise on the mics early on in the evening, but overall the session went well. I used my SASS with EM-172 capsules for this. EM-172s aren’t typically all that sensitive to humidity, so I’m looking into why the mics glitched. So far I haven’t been able to reproduce it, but I might spend some time monitoring the next time I use this box just so I can hear if it’s happening again.

Meanwhile, here’s a long(ish) track from the test. It covers the sunset transition from primarily birdsong and insects to the coqui frogs dominating the soundscape. And there’s the occasional cow. (I really love the way cow calls reverberate through eucalyptus trees.)

Posted in Uncategorized | 1 Comment »

Alice Microphone – Switchable Voicing

Posted by Tom Benedict on 10/05/2017

Back when I built my first Alice microphone I intended to use it for field recording. I took it out numerous times, but compared to other microphones I already had it always seemed noisy. Some testing indicated it wasn’t noise, just over-sensitivity to the higher frequencies generated by even the slightest wind in trees. Homero Leal pointed out that Ricardo Lee had documented an EQ modification to the Alice circuit on the Yahoo! micbuilders forum that could tame some of the high end sensitivity, so shortly after that I modified both of my Alice mics.

A couple of months afterward I started looking into voice acting. I have no aspirations of changing careers at this point, but I’ve been reading to my kids for close to eighteen years now, and one by one they’re starting to leave the nest. By the end of the summer the only way I’ll be able to read to my oldest is if I record each session and email the file.

To be fair the style of reading I do is closer to voice acting than straight reading. I like to give each character a unique voice. I like to read each book as if it was an old-school radio drama. So I knew my foray into voice acting would wind up being more than just figuring out how to record the sound of my voice. I wanted to become a better voice actor.

But yeah, I also wanted to learn how to record my sessions to the best of my ability. The more I poked into the technical requirements, the more I realized the Alice microphones make really nice voice mics. And the more I played with my TSB-2555B Alice, the more I realized I might want to disable the HF EQ mod for certain voices.

So I asked Ricardo if I could wire his HF EQ mod through a switch, making it an option rather than a default. He said the circuit isn’t particularly noise sensitive, and that he didn’t think there would be any problems. In the end I picked a switch that let me have three configurations: no HF EQ, Ricardo’s HF EQ to make the mic sound more like a U87, and one more that I haven’t committed to yet. (I’ll figure out how to wire that once I figure out which voices I need to EQ for.)

The fun part about adding the switch to the BM-800 Alice was figuring out how to mount it. I went back to the 3D CAD model I made of the mic, added the switch, and found I could fit some aluminum angle across the mounting holes on the opposite side from the PCB.

The only problem with that plan was that the aluminum angle had to fit inside the body tube of the mic. The top needed to be round, and for it to blend with the rest of the microphone I needed the sides to be tapered, just like the Alice PCB.

There are plenty of ways to make profiles like this, especially if you employ the aid of a CNC machine tool. But part of the joy of making things, for me, is spending time with the tools, hands on the handwheels, coming up with ways to get exactly what you want.

Switchable HF EQ

I wound up machining a lathe fixture to cut the profile. The fixture mimicked the internal frame of the BM-800 microphone, complete with screw holes and taper. Once I’d drilled the holes in the aluminium angle on the mill, I bolted it to the fixture and chucked it up in the lathe with the compound slide set over the necessary 2.3 degrees. It worked like a charm.

The switch isn’t the most convenient thing in the world since I have to take the body tube off the mic to change its position, and since the M-S Alice uses both sides of the frame it’s not something I can apply to that mic in its current form. But for now I’m not planning to use the M-S Alice for voice, and changing the mic’s characteristics isn’t something I’d want to switch on the fly, anyway. I think it’ll work out ok.

I’m still working through the nightmarish acoustics in my house, but with the help of a number of voice actors who have been kind enough to answer my barrage of questions, I think I’ll eventually get that sorted as well.

Posted in Uncategorized | 4 Comments »

Weatherproof Recording Box

Posted by Tom Benedict on 07/05/2017

In earlier posts I’ve mentioned that I do most of my field recording by dropping off my gear and recovering it later. This works great for a lot of reasons, not the least of which is that I make noise constantly. By using the drop-and-recover technique, I can get as far away from my mics as possible.

Another advantage of this technique is that I’ve found it takes between fifteen to forty five minutes for wildlife to return to their normal behavior after they’ve been disturbed. Since I can record for upwards of 24 hours using this technique, this means I get lots of time in each recording during which I know the animals I’m hearing aren’t stressed.

The big drawback to this technique, though, is that when something goes wrong I’m not there to deal with it. The first time I left my gear out overnight it rained. I’d planned for it by draping my recorder with a plastic bag, but it was a stop-gap measure at best. I wanted something more permanent.

Months ago the nearby Costco began selling ammo boxes. My wife picked one up for me, figuring it would be a good starting point for a weatherproof recording box. I hemmed and hawed about what I wanted the box to do and how I wanted it to do it, and finally came up with a plan.

Weatherproof Recording Box

I wanted the box to be able to hold my recorder and an external battery pack, and provide weatherproof XLR connectors I could plug mics into without risking the integrity of the weather seal. I came up with a couple of pencil sketch designs, but none of my plans beat a piece of equipment that already existed: the weatherproof outlet cover.

Four Channels

I had to modify the outlet cover so it had an opening large enough for the four XLR panel connectors. I did the work on the Bridgeport, but similar results could be had by using any number of other techniques such as saw and file, Dremel or Foredom, etc.

The panel connectors are standard Neutrik parts. I picked up the rainbow colored grommets (also Neutrik parts) to provide additional weather sealing and to let me color coordinate the connectors on the inside.

Weatherproof Routing

Cables route in through the slots at the base of the box (in this case I only opened up one, though I’ll probably have to open up the other once I start recording four channel sound.)

It Closes!

Once the cover is closed the only way water can get into the connector area is to come in through the slot at the bottom of the box. It won’t stop immersion or flooding, but it stops even the horizontal rain we get here in town. (I had my kids spray the box aggressively with the garden hose before I trusted it to hold my equipment. Everything stayed nice and dry!)

Color Coordination

I lined the inside of the box with foam that I covered with leftover head liner material I had from when I replaced the head liner in my Civic. The foam panels are removable in case I change my mind or need more space inside, but for now they provide some measure of cushioning and no small amount of insulation for when conditions turn cold at night.

The inside connectors are also standard parts from Neutrik with boots that match the colors of the panel grommets. Unfortunately connector lengths caught up with me.

The Tight Fit

When I started this design I hadn’t planned on lining the box with foam. That came later once I realized how much my gear would rattle around if I did any hiking with the gear inside.

But once the foam was installed, the full-sized Neutrik connectors poked out so far I could only plug things in on one side of my recorder. Since the fourth channel is located on the opposite side from the other three on the DR-70D, this means I can’t actually plug in all four channels yet. At some point down the road I’ll replace all four with low profile right angle connectors from Cable Techniques, but for now I get two (well… three) channel sound.

I’d intended to build this box in time for the 2017 International Dawn Chorus Day. Unfortunately I missed by hours. IDCD 2017 happened at dawn this morning, and I just finished the box an hour ago.

Ah well…

Meanwhile I’ve got a setup that will let me do drop-and-recover recording, rain or shine, and keep my gear safe, sound, and dry.

UPDATE: I finally had the chance to answer one question I had about this design: With the foam lining, would I run the risk of overheating the gear in the box?

The answer is a qualified no. I put my recorder and my 10000mAh battery pack in the box with a temperature probe and closed the whole thing up. Ambient temperature was 21C. The temperature in the box rose steadily for the first hour, then began to roll off. After seven hours the temperature reached 32.5C with clear signs it would asymptote at or below 34C. That’s a delta of around 13C.

The DR-70D operating range is 0C – 40C, according to the Tascam web site. When I originally ran this test I thought this meant I was marginally safe. I’m pretty sure I was wrong. In the test I was measuring the air temperature inside the box, not the temperature of the electronics, which were considerably warmer than the air temp.

I came up with a fix for this and the connector issue, which I describe in the second part of this article: Weatherproof Recording Box – Part 2.


Posted in Uncategorized | 3 Comments »

Another Stab at Contact Mics

Posted by Tom Benedict on 07/05/2017

Several months ago I ran a bunch of tests on a contact mic to try to figure out the best (ok, best of several options) way to interface them to my recorder. It wasn’t the most exhaustive test, but it at least pointed me in a good direction.

Specifically I wanted to find which configuration had the best low frequency response. To that end the mic under test was a 35mm piezo element stuck to a subwoofer, and the tests consisted of running a frequency sweep through the subwoofer while I recorded the output of the contact mic.

I tried four configurations: 1 – direct TS plug-in, with all the high pass filtering that leads to. 2 – HOSA MIT-129 impedance-matching transformer. 3 – Alex Rice impedance matching preamp. 4 – Stompville impedance matching preamp.

It wasn’t the best subwoofer in the world so the data was lumpy, but a couple of things came through pretty clearly: Not surprisingly, the direct-plugin lost some of the low-end. The Alex Rice preamp is known to have noise issues, which also came out in the tests. As far as signal to noise went, the HOSA MIT-129 and the Stompville preamp were very close across the range of the test (10Hz-1kHz), but the Stompville had higher overall signal and required less gain out of the recorder.

My point in running these tests wasn’t to prove once and for all which setup was the best. It was just to get some direction for how to build my next round of contact mics. I decided to go with the preamp from Stompville and run with it.

Before going into just how I ran with it, here’s some background on the Stompville preamp: SmudgerD started the same place I did, with the Alex Rice preamp, but instead of just being frustrated with the noise floor, decided to redesign it, and then further refine it. The result is a very well thought out design. Even better, SmudgerD packed the whole thing onto a tiny PCB that fits on the back of a Neutrik XLR panel jack.

I bought two.

(But I wish I’d bought four.)

Then I stuck them in a box.

Contact Mic Preamp Box

The bottom of the box is tapped 1/4″-20 so I can attach it to the top of my DR-70D using the camera mount thumbscrew. Two of the Stompville preamps face out one side, and as soon as I buy another two they will face out the other side. The third face has a row of mini-XLR connectors for plugging in the contact mics themselves.

I was turned on to the mini-XLR connectors by Mo, who shared them in a comment on my EM-172 and XLR Plug article. I have to say these things are the cat’s pajamas. They’re small, they’re inexpensive, they have a positive lock, and they have the neat feature of having pin 1 make contact before the other pins. This ensures ground makes contact before the signal pins. I love ’em.

Unfortunately, right after I finished the box I was drawn into other things. So I only have two contact mics built so far. The first is the one that’s still attached to the subwoofer. The other is a prototype I built to test the preamp box in the field.

Prototype Contact Mic

It’s ugly, but it works remarkably well as long as you don’t apply any pressure on the center of the piezo. (This introduces a large DC offset.) The next rev, of which I’m building four, will be fully enclosed.

Just for grins I took the whole mess in to work to play.


– Tom

Posted in Uncategorized | Leave a Comment »

Rest In Peace My Friend

Posted by Tom Benedict on 07/01/2017


5 May, 2010 – 6 January, 2017

Rest in peace, my friend

Can your tongue do THIS?!


Ember, Coned


Ember - Second Splint


Ember: Amputee


Edit Kitty


Ember - Done


Sunset Ember


Ember Sleeping - Close-Up


Posted in Uncategorized | Tagged: , , | 6 Comments »

Why I Don’t Like Targeted Advertising

Posted by Tom Benedict on 10/05/2016

It’s the new “thing” in marketing: targeted advertising. Instead of getting broad-based advertising you may or may not be interested in, advertisers are now contracting with search engines like Google to target their ads to people who are interested in their products. More efficient advertising! It’s great, right?! The way it works is simple: You search for something, then that thing appears on every… freaking… web page… you visit.

Two problems with this scheme: Back when I bought my DR-70D recorder, I did something remarkable. I actually bought it! So for the next three months I got ads trying to get me to buy (drum roll for the oblivious here) another DR-70D recorder! Every time I started a browser it showed up. Buy me. BUY ME! BUY ME!!! Way ahead of you, bro. Now SHUT UP!

But I shouldn’t complain, because at least it meant I wasn’t getting ads for other things during that time. (Oh yeah, it gets worse.)

A little later I was looking for cylindrical mirrors for a project at work. I wasn’t looking for much. Just some Pyrex tubes I could aluminize in our small chamber so I could do some tests. Nothing big, maybe 25mm in diameter. So I searched Google for small Pyrex tubes, and by golly I found some! Just the right diameter, just the right length, just… some part of some sort of heated ultrasonic delivery system or something?

They were replacement tanks for a particular model of e-cig. I really don’t like e-cigs. I really really don’t like them. Among other things kids at the schools around here are using them to inhale THC-laced liquid and exhale the fumes onto other kids. My kids. (I REALLY don’t like these things.)

No problem, right? Just close the search window and find some other source for Pyrex tubes. Never have to think about it again. Simple!


For the past three months I’ve seen ads for e-cigs every time I start up a browser. Hey, I searched for it so I must want to buy it, right? Buy it! BUY IT! E-CIG E-CIG-E-CIG!

I tried searching for other stuff. I tried cameras. I tried microphones. I tried anything that would get that damn e-cig ad off my browser. It didn’t work, though. I just have to wait it out until the damn thing goes away.

This is one of the many reasons why I occasionally go full-throttle Luddite. My #2 pencil never pulled this crap on me.


Posted in Uncategorized | Tagged: , , , | 2 Comments »

Life, Or The Effects Thereof

Posted by Tom Benedict on 23/03/2016

Despite the progress I’ve made on my sound gear I haven’t had much of a chance to get out with it. Life, or the effects thereof, got in the way.

A little over a month ago I wound up with severe neck and shoulder pain. It took about three weeks to get a slot with a physical therapist, but that meant I had time to get my x-rays done in advance. The results weren’t great. Years of kite flying combined with overall bad posture means I’ve partially compressed one of the discs in my neck, and decades of neck jerking tics because of my Tourette’s means I’ve given myself repeated whiplash injuries in the same general area, and the beginnings of arthritis in my spine. PT is going well, but I’m not in a position to carry gear, fly a kite, hike, etc. So I’m out of commission when it comes to sound recording, kite aerial photography, photography in general, RC airplane flying, or pretty much everything else I do for a hobby. For the record, I’m officially broken.

Another two to three weeks should see me past the worst of the pain, but I can’t keep doing things the way I have been. Part of the physical therapy is re-learning how to look up. Despite how simple this sounds I’m trying to un-do forty seven years of bad posture. Even if I pull it off (and I’m bound and determined to pull it off!) when I do get back into KAP in a serious way I’ll need to use belay glasses or something similar in order to avoid further injury to my spine. Likewise if I stick with the PT regimen I should be able to wear a backpack again some time in the near future. But walking for hours carrying twenty pounds of KAP gear is off the list permanently.

I don’t necessarily have to give up any of my hobbies, but I do need to re-think how I do them. I’m trying to re-think how I carry sound gear so most of the weight is contained in a waist pack. There’s a fantastic thread on the KAP Forum about repackaging RC transmitters into more compact and much more functional units. Meanwhile lighter, more capable cameras have come on the market that mean there’s no real point in flying a DSLR from a kite any more. If I can shave the weight I’m carrying and figure out better ways to carry it, I should be able to keep on playing for many many decades to come. But if I don’t make the effort the outcome is certain.

Take care of yourself. There’s only one you in all the universe.


Posted in Uncategorized | 2 Comments »

Losing my Mathematical Marbles

Posted by Tom Benedict on 26/02/2016

Some months ago a co-worker and I were characterizing a pressure and vacuum system at our summit facility that changes its output as a function of angle off of zenith. As boring as that may sound, that’s nothing compared to what it actually meant for the people doing the characterization. Until something new comes along it’s my gold standard definition of boredom:

“Moving to plus thirty degrees. … Mkay.”

“Kay… Ok, go to plus fifteen.”

“Moving to plus fifteen degrees. … Mkay.”

“Kay… Ok, go to zenith.”

“Moving to zenith. … Mkay.”

“Kay… Ok, go to minus fifteen degrees…”

It went on like this. And on… And on… We made scans from +75 degrees to -75 degrees in fifteen degree increments. Over and over and over, day after day. By the end of a week of this my brain went off into some mathematical neverland. Positive angles were boring because they were what they were. No depth to them. No nuance. But negative angles… oooh, they’re tricky.

The rotary stage we used doesn’t do negative numbers. It wraps around to 360. So the negatives go from 0 to 345 to 330 to 315 to 300 to 285. The first fifty times or so you can convince your brain there’s nothing wrong. But by the time you’ve done hundreds of scans weird things start to pop out at you. I found myself thinking, “If you take away fifteen from sixty, you get forty five! And if you add forty five to fifteen you get sixty! And seventy five is a multiple of five and five and THREE!!” It was epiphany after epiphany! This stuff was MAGIC!

I think some of this had to do with the inane repetitiveness of what we were doing. I think the rest can be chalked up to oxygen deprivation. Luckily by the time I got down at night my brain had calmed down enough to realize how bizarre my mental state actually was. I opted not to share my new-found knowledge with my kids so they never had the chance to say, “Dad, I think you’re off your rocker. That’s basic math.”

This is why I fear the question every kid asks: “Are we really going to use this math stuff once we’re out of school?” I’m afraid of what I’d tell them.

– Tom


Posted in Uncategorized | Leave a Comment »