标签: prognostication

My friend Rick Curl dropped into my office several days ago on his way to a conference or exhibition or something. It's been a while since Rick was up this way, and he wanted to see my Bodacious Acoustic Diagnostic Astoundingly Superior Spectromatic (BADASS) Display doing its funky thing.   While Rick was here, he also feasted his orbs on the current state of the cabinet I'm going to use for my Pedagogical and Phantasmagorical Inamorata Prognostication Engine . As you may recall, this project is coming along in leaps and bounds. I now have awesome new faceplates for my antique analog meters, and my master carpenter friend Bob created an additional box to sit on top of the 1929 wooden radio cabinet I'm using to house the main engine.     I've also got all the brass control panels cut and poised to be added to the various cabinets. The photo below shows some of the pieces that will be used for the upper cabinet. The large hole on the left will be used to house my "Behold The Man" meter, while the hole on the right will hold the small coal-fired furnace used to power the beast (not a real coal-fired furnace, of course, but it will look like one).     There's also going to be an antique knife switch mounted on the front right-hand side of the lower cabinet. The sort of switch Igor throws just before Baron Frankenstein cries "It's Alive! It's Alive!"   Now, my original idea was that throwing this switch would cause the furnace to spring into action, and -- from there -- the other units to undergo some sort of power-up sequence as they flickered into life. In hindsight (the one exact science), this was rather boring, because Rick has come up with the most amazing idea for an awesome startup sequence.   Picture the scene... We start with a copper or brass pipe sticking out of the right-hand side of the upper cabinet level with the center of the furnace. This pipe then makes a 90° downward turn, ending in a funnel as illustrated below.     On the floor under the Prognostication Engine will be what looks like a set of antique foot-powered bellows with a tube feeding into the lower cabinet. The operator will have to pull this out in front of the cabinet before proceeding further.   So, the start-up sequence will be as follows. First you have to place the knife switch into its "On" position. Next you have to hold a real lighted flame under the funnel. Finally, you have to start pumping the bellows with your foot. A temperature sensor will ensure that you really do have a lighted flame, while a pressure sensor will detect every "puff" from the bellows.   After a couple of seconds holding the flame, the furnace will start to glow deep red. Every time you puff the bellows, the furnace will pulse a little brighter, but you will really have to work the bellows hard to persuade the furnace to move from a pulsing red to a flickering orange to a crackling yellow.   Only when the furnace is blazing away (with appropriate sound effects, of course) will the operator be able to remove the flame and stop pumping.   The user can then slump to the floor, gasping for breath and drenched with sweat, basking in the glow of a job well done (and/or in the glow from the furnace) whilst delighting in the sight of the various portions of the system gradually sequencing into operational status.   I'll also implement a secret short-cut for my own use, but I won’t tell my guests about that until after they've powered up the engine using the above scheme (LOL). One thing that was worrying me was where I could acquire the brass funnel, but then I thought of a musical instrument like a horn or a trumpet.     As an aside, I used to play the trumpet and trombone (not at the same time, of course) in the orchestra when I was at high school, but we digress...   So, if you happen to run across a battered old brass trumpet on your travels (or if you have one gathering dust in your loft that's surplus to requirements), please write a comment below. In the meantime, what do you think of Rick's ingenious idea?

I'm now cursing myself for being a fool. I have let chances and opportunities slip between my fingers. I deserve to be berated soundly. But what is the cause of this gnashing of teeth and rending of garb? Well, let me explain …   As you may recall, my Inamorata Prognostication Engine is to be mounted in an antique (circa 1929) wooden radio cabinet. On top of this will be a box containing my Ultra-Macho Prognostication Engine . And on top of this will be an array of vacuum tubes.     The five tubes I've decided to use are incredibly tasty and rather large as these things go. They currently reside in a box on the floor of my office as shown below. Just to provide a sense of scale, the largest tube in the upper left-hand corner is about 12" (30 cm) tall.     In the fullness of time, I will be lighting these tubes using tri-colored LEDs. Do you recall this video showing me holding the large tube in my hands while a band of Adafruit's NeoPixels illuminate the tube from its base? I think you'll agree that the end result is rather spectacular. Now imagine all five of the above tubes lit up in the same fashion.   One of the problems I've left on the back-burner is how I'm going to attach these tubes to the brass panel that will be mounted on top of the Ultra-Macho Prognostication Engine. I knew at the back of my mind that there must once have been proper holders for the tubes, but I never really thought about it all that much. And, if I had thought about it, I would probably have assumed that it would be difficult to find a bunch of different holders.   This is the point when I start to slap myself on the head, because I never really looked closely at the bases of my tubes. I'd assumed that they would all be different on the basis that the tubes themselves look so different. The end result is that I only just discovered that the bases of four of the tubes are identical -- only the little rascal shown in the upper right-hand corner of the box has an alternative configuration.   So how did I come to this realization? Well, while I was at the Huntsville Hamfest earlier this year, I picked up all sorts of interesting things. The photo below shows my treasures spread out across our dining table.     In particular, note the three tubes in the far right-hand corner. These little scamps are currently sitting on the book shelves in the Pleasure Dome (my office) awaiting a suitable project. Now, these tubes are smaller than the ones I'll be using for Ultra-Macho Prognostication Engine, so I'd not really given them much thought. However, I happened to glance at them the other day as I was ambling back to my desk with a cup of coffee, and my attention was caught by the ceramic mounts holding these tubes.       I realized the tubes were held in place by a sort of bayonet fitting. When I took one of the tubes out, I saw it had four pins on the bottom. As near as I can "eyeball it" here in the office, these pins are each 3/16" in diameter, and the main metal collar on the base has an internal diameter of 1 13/16".   When I peeked at the tubes I'm going to use for the Ultra-Macho Prognostication Engine, I realized they had the same four pins. "Could it be?" I thought to myself. Well, blow me down, all four of my big tubes work in this holder, so ideally I need four of these bases -- all identical. And then there's the final tube as shown below.       In this case we have four pins, each 5/16" diameter, arranged in a sort of diamond formation (with an additional glass protuberance in the middle). The frustrating thing is that -- now I know what I'm looking for -- I bet I could have picked these tube holders up at the Huntsville Hamfest.   If all else fails, I'll have to wait until our EETimes Road Trip to Hamvention, but that's not until May 2015 and I'm an impatient man. So, do you have any ideas where one can find these sorts of tube holders?

Well, the excitement is escalating, let me tell you. I'm happy to say that both my Inamorata Prognostication Engine and my Ultra-Macho Prognostication Engine projects are currently racing "full steam ahead."   Having made the final selections on exactly which antique analog meters I intend to use for the Inamorata Prognostication Engine, I assembled all of the meters, buttons, switches, and knobs onto the brass panels and brass bezels as seen below. You may recall that the main enclosure for this engine is to be an antique wooden radio cabinet circa 1929. What we see here is a test jig that will hold everything in place while I create the wiring harness and make sure everything works as planned.   Inamorata Prognostication Engine control panels in their test jig   Note that the interestingly-shaped piece of wood in front of the lower brass panel is just hardboard that I cut out for this jig -- the equivalent piece on the real cabinet is dark cherry that looks much nicer and really complements the brass.   The two holes on either side of every momentary push button and toggle switch will each have a tri-colored LED behind it (I'm using the Flora NeoPixels from Adafruit for this purpose). Similarly, the sixteen holes surrounding each of the potentiometers will each have its own tri-colored LED (in this case I'm using NeoPixel Rings ).   In front of each of these LEDs will be a mother-of-pearl "dot." Actually, these are plastic facsimiles that were originally intended to be used in the frets for guitars, but they look like the real thing. When this all comes together, the combination of the dark wood, the brass, and the mother-of-pearl dots will look incredible, even when the beast is powered down.   I will be attaching the LEDs this coming weekend so that I can begin to wire everything up, but I will wait to insert the mother-of-pearl dots until after I've aged the brass panels.   One of the things that have been delaying this project is the problems I've been having with my antique analog meters. This started with the main meter for the Ultra-Macho Prognostication Engine (see this blog ), but then I discovered that some of my other meters were also sticking (sad face).   This left me in something of a quandary. Fortunately, a feedback on the aforementioned article led me to Instrument Meter Specialties (IMS) -- a company that specializes in anything and everything to do with both antique and modern meters, including repairing and restoring the little beauties (see this blog and this one too ).   Quite apart from anything else, these folks often create new faceplates for bold old and new meters. For the last week I've been bouncing ideas back and forth with Jason Dueck at IMS. This past weekend he emailed me a copy of the proposed graphics for a new front plate for my "Full Moon" meter as shown below.     You wouldn’t believe how much cogitation goes into this sort of thing -- it's not just a case of creating each meter in isolation -- you have to think about how all of them are going to look in relation to each other. I could write an entire column about the thought that went into creating the above layout, but we'll leave that for another day.   In the meantime, I do have a question for you with regard to the above image. Note the negative numbers on the left are (not surprisingly) prefixed by '-' signs. By comparison, the positive number on the right doesn't have a '+' sign. Jason informs me that, in this sort of situation -- mixing negative and positive quantities -- omitting '+’ signs was the old pre-WWII way of doing things. These days I think people do tend to use them (only if there’s a mix of negative and positive quantities; if everything is positive then we wouldn’t bother with '+' signs). So, in the case of the faceplate shown above, which do you prefer; should we add the '+' sign or should we leave everything as is?   As I mentioned in a previous blog, I was dreading having to open my meters up once again to replace the faceplates (every time you open one of these sealed units, you run the risk of messing something up). So I can’t tell you how happy I am that Jason and team have offered to take this task over. This evening I'm going to take the meters off the test jig and ship them to IMS where they will be cleaned and fine-tuned, have their faceplates swapped out, and be fully checked before being returned to your truly (happy face). But wait, there's more, because I've been performing further experiments with regard to giving my brass panels an aged look...   Yet more brass-aging experiments Do you remember my earlier trials using Cow Pool Horse Doo-Doo ? Well, suffice it to say that working with these substances is not as much fun as it sounds, so I decided to investigate more conventional techniques.   When you perform a Google search for "Aging Brass" on the Internet, the responses can be wide and varied, but several people mention using salt and/or vinegar. In the case of the vinegar, I decided to use the English malt variety. Why? Well, for one thing I like the taste of malt vinegar. With regard to salt, I opted for using large Himalayan pink rock salt because I happened to have a jar to hand and I thought the minerals in it might enhance the effect.     I obtained a load of cheap plastic containers and put a piece of brass in each. In one, I covered the brass with malt vinegar on its own. In another, I covered the brass with tap water and then I added some coarsely crushed rock salt on top. And in a third, I covered the brass with vinegar and then added crushed rock salt on top.     I did all of this about ten days ago. After seven days I took a look to see what was happening. The answer was "Not much" (I'll check again at the 14-day mark). Fortunately, a few weeks ago I laid my hands on a copy of Patina: 300+ coloration effects for Jewelers and Metalsmiths by Matthew Runfola, and I remembered him mentioning that some interesting effects could be obtained using sawdust.   The last time I visited my master carpenter chum, Bob, I asked him to give me some sawdust, and I returned home clutching two bags -- one containing fine sawdust of one type of wood and the other containing medium-coarse shavings of another type of wood.   Thus it was that, at the same time as I set up the experiments using the salt and vinegar solutions directly, I also set up a second batch of experiments using identical solutions (except I ground the salt up finer and made sure it was fully dissolved) poured into containers of sawdust.     Oh, I forgot to mention that I also added an experiment using ammonia and another experiment using a different substance. Take a look at the image below. The blue/green brass test piece in the upper left-hand corner was exposed to the gas emitted from household ammonia for three days. I actually used a small sheet of old fired clay to keep the brass out of direct contact with the ammonia liquid. What we see below is the upper face that was exposed to the vapor only.   Rear from left to right: "Face-up" sides of brass panels exposed to household ammonia (3 days), salt + vinegar with fine sawdust (1 week), salt + water with coarse sawdust (1 week), and vinegar with coarse sawdust (1 week). Front: don't ask!   To the right to the ammonia test we see the results of the brass that was left in a salt and vinegar mixture in fine sawdust for a week. To the right of this we see the results of salt water in coarse sawdust for a week. Finally, the right-most piece was exposed to malt vinegar in coarse sawdust for a week.   What? You desperately want to know about the substance that resulted in the blue piece of brass in the foreground. Well, let's just say that this predominantly consists of a heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula C 5 H 4 N 4 O 3 . In turn, this largely started out as a fermentation of malted barley, malted wheat, and hops (in the form of Boddingtons finest beer), which -- by a miracle of evolutionary biology -- underwent a process of transmogrification, followed by an exchange of electrolytic fluids, ending up in a container of fine sawdust.   But let's not wonder off into the weeds. Another interesting aspect to all of this is that the effects vary depending on which side of the test pieces we're talking about. The image below shows the bottom sides of the test pieces.   Rear from left to right: "Face-down" sides of brass panels exposed to household ammonia (3 days), salt + vinegar with fine sawdust (1 week), salt + water with coarse sawdust (1 week), and vinegar with coarse sawdust (1 week). Front: You really don't want to know!   I'm assuming that the more pronounced effects are caused by the weight of the brass pressing down on the moist sawdust (the sawdust should be heavily moistened, but not soaking). The two pieces I find most interesting in the context of the brass panels for my Inamorata and Ultra-Macho Prognostication Engines are the ones exposed only to salt or to vinegar as shown in the close-up images below.   Close up of "face-down" side of brass exposed to salt + water with coarse sawdust (1 week)   Close up of "face-down" side of brass exposed to vinegar with coarse sawdust (1 week)   I think it's safe to say that I'll be concentrating on the use of coarse sawdust/shavings. Unfortunately, I neglected to question Bob as to the types of wood these were. But that doesn’t matter, because now I intend to embark on a new round of salt and vinegar experiments using a variety of different wood types and exposure times.   In the meantime, what do you think about the effects I've achieved thus far? Do you think one (or both) of these could be of interest for my Prognostication Engines? Or do you thing they are a bit much and that I should continue on my quest?

Well, so it's true, life is full of ups and downs. When it comes to the antique analogue meters I'm using in a number of my hobby projects, things appeared to be going swimmingly well, and then disaster struck. On the bright side, I have high hopes that a reader can help, and that may be you.   As you may recall, I have several hobby projects on the go that will feature antique analogue meters. They include my Inamorata Prognostication Engine , my Ultra-Macho Prognostication Engine , and my Vetinari Clock .   I've been gathering the requisite meters for some time. At the same time, I've been masterminding the brass control panels and the wooden cabinets, working on the software algorithms, and generally running around doing all sorts of other things. As a result, it wasn't until this past weekend that I actually started testing and characterizing the meters themselves.   First of all, we (my electronics guru chum Ivan, who works in the same building, and I) opened all the meters up to check for (and, if necessary, remove) internal series or shunt resistors. The image below shows some of the meters I'm using spread out on a table in my office building. The four meters dismantled in the foreground are intended for the Vetinari clock. The five-meter group in the background is destined for the Inamorata Prognostication Engine; these have already had their series and shunt resistors removed.     The next step is to determine the value of the new external series resistance to be used with each unit. Depending on the unit in question, this can be all over the place. For example, one of my meters requires an external series resistor of only 370 Ω, another requires 5.47 KΩ, and one requires a hefty 98.6 KΩ. Since I plan on using analogue meters for a lot of future projects, it makes sense for me to streamline this process, so I whipped up the handy-dandy unit shown in the black box below.     The Arduino appearing in the bottom lefthand side of this image (under one of our screw-block proto-shields, which is itself under an I2C-based LCD display shield) is driving a pulse-width modulated signal. For the purposes of this test, I'm driving a maximum value of 255. This is being fed via an isolating field-effect transistor into the input terminals on the lefthand side of my black box. The output terminals on the righthand side of the box are used to drive the meter.   The three potentiometers allow me to start with a very high value of series resistance and work my way down. The switch in the middle of the black box is a two-pole, two-throw, three-position device that allows me to swap the polarity of the terminals driving the meter. Again, I'll be describing this in much more detail in a future column.   Generally speaking, everything went rather well. Once I'd constructed my test unit, it didn't take long to determine the series resistors required for all my meters. The only problem occurred when I discovered that my biggest and best meter -- the Phaostron device I intended to use in my Ultra-Macho Prognostication Engine -- has twitched its last and shrugged off this mortal coil (pun intended). Much like the Norwegian Blue in Monty Python's Dead Parrot skit , my beauty is no more. It has ceased to be. It has expired and gone to meet its maker.   This is a bit of a blow and no mistake, because the brass panel for my Ultra-Macho Prognostication Engine has already been fabricated. Suffice it to say that I am not performing my happy dance. The two Phaostron meters below are also unusable (I keep them around for spare parts). The one on the left is model number 40-014036; the one on the right is model number 40-013857. I'm sure there are other models out there that would fit the bill.     The physical characteristics I need include the black surround with the six mounting holes. This surround has an external diameter of ~4.5". The "can" that protrudes through the brass panel has a diameter of ~3.5". With regard to the electrical characteristics -- and remembering that I eventually will replace the faceplates -- I don't care if the meter was originally intended to display voltage, current, resistance, or some other quantity, as long as it works with direct current (DC), not alternating current (AC).   This is where you come in. Do you perchance have one of these meters in your treasure chest of spare parts? Or do you know where one can be found? Or will you be attending a Hamfest or electronics flea market in the foreseeable future? Of course, a group of us will be attending Hamvention next year, but I don't want to wait that long.   If you responded "Yes" to any of the above questions, please post a comment below. I await your communication in dread anticipation.

As you may remember, one of the things I want to do with the brass panels I'm using in my Inamorata Prognostication Engine is to make them look really old. Since everything is being mounted in a beautiful wooden radio cabinet circa 1929, and since I'm using antique knobs and switches and dials and meters, I want my brass panels to fit in with this overall look-and-feel.     If you Google the topic of "Aging Brass" you will discover myriad suggestions, including the use of salt, vinegar, ammonia, temperature, and a mixture thereof. I'm still planning on evaluating all of these techniques as soon as a get a spare moment (I had the offcuts left over from my brass panels sliced-and-diced into small strips -- approximately 4" x 1.5" -- for just this purpose).   One thing someone mentioned to me was that the Imagineers at Disney use cow manure to age their brass. This sort of makes sense, because cow manure contains all sorts of things, including salts, acids, and ammonia, to name but a few.   I mentioned this to my inventor friend, Brian LaGrave, who lives in the country about 40 miles away from me. Brian has two young sons, Sam and Daniel, who were duly dispatched to fill one large plastic coffee container with cow poop and a second container with horse doo-doo. The next time they came into town, they presented these gifts to me at the Pleasure Dome.   That evening, I transported these containers home and surreptitiously hid them in a corner of our garage. At the weekend, while Gina was at work (she's a realtor and thus works at the weekends), I pressed a piece of brass into the heart of each amorphous deposit (yes, of course I was wearing latex gloves).   Originally, I was planning on pulling the brass pieces out once a week to see how they were progressing, but plunging your hand into cow and horse manure is not as much fun as it sounds, so I ended up leaving them for six weeks or so.   During this time, Gina occasionally mentioned "interesting smells in the garage," but I suggested that these may be emanating from the bags of organic compost she had purchased for her potted plants.   The image above and the images below show the two pieces of brass side-by-side. Each image shows one face of the brass or the other under different lighting conditions (the colors and effects are far more interesting when viewed by the naked eye). In all cases, the brass that was buried in cow poop is shown on the left, while the brass that sojourned in horse doo-doo is presented on the right.                   I have to admit that I was surprised by the difference in effects caused by the two types of manure. Of course, these results are only from one cow and one horse, so more experimentation needs to be performed. Also, as I mentioned, I left my brass test pieces buried in the manure for six full weeks. It would be interesting to compare the results day-by-day -- maybe create a video using a sort of time-lapse photography effect.   One more consideration is that I used "raw manure" that contained lots of chunks of indescribable stuff. It may well be that one would obtain more consistent results if the larger pieces were filtered out and the rest was watered down into a sort of slurry (I'm thinking Sam and Daniel may be in for an unpleasant surprise in the not-so-distant future LOL).   Now, I should note that the effects I've achieved thus far are a trifle on the bold side and not what I'm looking for. Unfortunately, I'm not sure exactly what I am looking for, but I'll know it when I see it. All I know is that I want something that looks old and interesting and has a patina that makes you want to say "Ooh, tasty!"   On the bright side, I'm happy to be learning something new. I'm also happy to be discovering stuff that doesn't seem to be documented anywhere. On the other hand (no pun intended), you can only have so much fun rooting around in containers containing "goop" that is dark, sticky, and noxiously smelly. I have to admit that the thought of simply purchasing a container of commercial brass-ageing solution does have its attractions (doubly so for Sam and Daniel LOL).   How about you? Have you had any experience in aging brass? If so, any advice would be very much appreciated -- especially if it doesn’t involve any more hands-on experiments with nauseating substances.