Oh, you're such a tease! You show us a beautiful piece of old electromechanical (and pneumatic!) equipment and you don't even take the covers off! That's got to be the only piece of aeronautical test equipment with an included bicycle tire pump. I can't wait for the repair video. Thanks!

Last time I used one of these was for calibrating barometric transducers for the Jindivik 103A & 103B and Meteor U16 targets at RAE Llanbedr in the mid to late 1970's. The Extra High Altitude transducer (for certain Jindivik configurations) covered the range 45K to 65K feet...!

Flash from the past!!! I haven't seen one of those since I left Smiths Industries 25 years ago. (Smiths used to make these)

@CuriousMarc

11 ай бұрын

It is a Smiths machine indeed!

it's like a puzzle in Myst or The Room

@CuriousMarc

11 ай бұрын

Oh I loved that game.

Just heads up CuriousMarc - letting the altimeter move that quick can damage the delicate bellows and mechanical bits in the instruments and in your test-set. A good rule of thumb in aviation (where we still use test-sets like this daily) is want smooth, slow applications of pressure and vacuum to the system you are testing. Typically you don't want to exceed 2500-3000 ft/min on altimeters and nice and smooth on pitot pressure.

@CuriousMarc

11 ай бұрын

It’s sped up. And you can’t hurt these: it’s a balance system and the total travel of the capsules is limited to a fraction of a millimeter. It also has a valve that will automatically equalize pitot and static should pitot become less than static.

Historical Prestige requires you to do a full video on this tool and how it works as well as what the inside looks like.. please. 😄

@CuriousMarc

11 ай бұрын

For sure, it’s in the works.

Most elaborate bicycle pump I have ever seen 🙃

Hang on I've seen this thing. This is how Marty McFly blows up the giant speaker.

@CuriousMarc

11 ай бұрын

Wile E. Coyote also uses a model similar to this

@SeanBZA

11 ай бұрын

@@CuriousMarc Wile E Coyote though used the ACME Captain America model though, which has, to a great degree, still survived in operation to this day, as it is still used where you need to blast in an explosive atmosphere, as it has the advantage in that, till you prime the big capacitors in it with charge, there is no way to develop any sort of electric discharge. But you can still verify the integrity of the firing circuit with lower energy after a single charge.

It could be the time circuits for a Doc Brown's '50s prototype of a time machine, haha! Might not be as stylish as a DeLorean, but hey - I love the antique aesthetic. Seriously though, I think it's an instrument calibrator.

@CuriousMarc

11 ай бұрын

Mystery solved. It’s a time machine. I knew it.

@JamesTK

11 ай бұрын

@@CuriousMarc yep. It's not only altitude you're going through but time and space!

Love your stuff Marc

Can't wait for the tear down / repair video with usual brilliant commentary 😊

@CuriousMarc

11 ай бұрын

Coming up soon!

More and more convinced that marc is doctor who's twin with gadgets like this in his basement

@CuriousMarc

11 ай бұрын

And my basement looks bigger on the inside than on the outside. Suspicious.

Yay @ not a short (despite the tag)

@CuriousMarc

11 ай бұрын

It’s a long short :-)

Thanks Marc.

@0:10 - This is the only moment in any of your content where my tiny wife - from across the room - went "SQUEEE" when she saw the minions. You have crossed the Rubicon now.

@CuriousMarc

11 ай бұрын

You have the best wife!

I’ve finally got round to adding a bit of context to my previous comment. These transducers formed part of an FM/FM Telemetry system designed in the 1950’s known as the RAE 6 channel system and compared to today's PCM system’s was fairly rudimentary. The telemetry system comprised of 6 analogue channels as follows. Chan 1 - Engine RPM 130Hz to 800Hz corresponding to 2,600 rpm to 16,000 RPM - via an engine mounted Tacho generator driving a motor fitted with a phonic wheel. Multiplying the frequency by 20 gave the equivalent RPM. Chan 2 - Not Used Chan 3 - High range Altitude Transducer 1380Hz to 1686Hz corresponding to 14,500 ft to 57, 000 ft. Chan 4 - Vertical Speed Transducer 2160Hz to 2640Hz corresponding to plus/minus 9000 ft/min Chan 5 - Low range Altitude Transducer 3380Hz to 4132Hz corresponding to 0ft to 15,000 ft Chan 6 - Airspeed Transducer 5291Hz to 6467Hz corresponding to 0 Knots to 460 Knots. Four inductance type transducers are used to convert pressure information into sub-carrier signals whose frequency varies with altitude (2 ranges), rate of climb & descent, and indicated airspeed. The transducers each consist of a movement operated by a pressure capsule, and inductance unit and a Colpitts valve oscillator. Variation of pressure inside the case or capsule produces expansion or contraction of the capsule. Axial movement of the capsule varies the gap between an armature on the capsule and the pole pieces of an inductance unit which forms part of the oscillator circuit. In this manner, the inductance value is made to vary with pressure, thus varying the output frequency of the oscillator. A further interesting write-up can be found at: www.icas.org/ICAS_ARCHIVE/ICAS1958/Page%20990%20Leslie%20et%20al.pdf

My guess: this is for your astronaut training camp before you finally build your own rocket and lunar lander 😄😄😄

Pitot-static systems on aircraft are part of the system that measures altitude, vertical speed, and airspeed. The static port allows measurement of outside air pressure, which is used to determine altitude (lower pressure --> higher altitude, and there's an adjustment that's made using a pilot-entered local barometric reading to give more accurate readings). Rate of change of the outside pressure determines vertical speed (i.e. climb or descent rate). Comparison between ram air pressure entering the forward-facing pitot tube and the ambient pressure measured by the static port is used to calculate airspeed. That measurement ("indicated" airspeed) has to be adjusted for instrument position error to yield "calibrated" airspeed, which is further adjusted for altitude and temperature to give "true" airspeed. At high speeds, air compressibility also has to be factored in. All of these instruments need to be tested periodically and adjusted/calibrated, which is what I'd assume this piece of equipment is for.

@CuriousMarc

11 ай бұрын

Yes you got it! We are going to use this to test our analog Bendix Central Air Data Computer

#Short #InTheRightOrientation the only shorts I will watch!

Push down handle: goes boom sky high. Neat one!

nice meeting you at the CHM today Marc!

@CuriousMarc

11 ай бұрын

Yes I really do exist! Nice to meet you too. Thanks for the kind encouragement!

Come on now... nobody likes a tease. The people need MORE!

@CuriousMarc

11 ай бұрын

More coming!

You stole that from the RAF ? The King will send more Minions around to retrieve the precious property pronto !

@CuriousMarc

11 ай бұрын

Oh no!

@SeanBZA

11 ай бұрын

@@CuriousMarc Don't worry, they sold it off before the Crown Jewels, after all the MOD needed to make money, what with the defence cuts all these years.

The pitot static system is primarily used to calculate indicated airspeed, so im guessing it simulates the air diferentials used to calculate the ias and tests indicator equipment?

@CuriousMarc

11 ай бұрын

It does.

@MeppyMan

11 ай бұрын

Used for altimeter and VSI too. I always wondered how they tested and calibrated the old “steam” instruments in the helicopters I used to fly.

Guess what this for, you ask? It´s obviously a time machine, if it should come with two _Minions_ installed.

The secret is out - this is how they make the sonic boom!

@CuriousMarc

11 ай бұрын

But you gotta pump really hard.

Awesome!

So much for "of course we have no way to calibrate our altimeters";-)

Looks like a tester if the instrument cluster of an aircraft

I'm pretty sure one of the knobs was labeled "predict next week's winning lottery numbers"...

This thing looks like an old movie prop!

Likely one of the top three most important instruments.

One of the IBM selectric please

Good thing, thy wrote "portable" on the unit. I wouldn't have noticed otherwise.

@SeanBZA

11 ай бұрын

As opposed to the larger version that sat in the service van, which was basically the same set, just with 10m long hoses to reach the assorted ports, and a chair to sit on. That one was integrated into the panel on the one wall inside the Citroen van, with the corrugated sides, and the half ton aluminium walkway on top, and the VW Beetle engine, as replacement for the original horrid Citroen one where you could not get spares for it..

Does this have a quartz Bourdon tube in it? I tore apart a few pitot/static testers a few years back for a friend (who sadly passed away) and all of them had quartz Bourdon tube pressure sensors in them. They were encased in an oven to stabilize them, and a small incandescent lamp and photocell were used for readout.

@CuriousMarc

11 ай бұрын

No, no such thing inside. It’s traditional pressure capsule, but tied in a servo controlled balance beam arrangement, so the capsules actually never move. Very clever.

Altimeter calibrator? QNH and QFE ?

I used it USAF Avoinics Maintance

You can tell it's British because the pressure gauges are in mBar but the max pressure is in PSI lol.

I believe that is how the HMRC calculated my tax this year.

I was an A4E Skyhawk avionics tech in the late 1960s. Our pitot/static teste was painted yellow. I don't have any pictures of me playing (testing aircraft) with it.

@SkyhawkSteve

11 ай бұрын

Small world! I was a Marine avionics guy on A-4M's and TA-4F's in the late 70's. We used the TTU-205 test set. Much easier to use... just dial in the desired airspeed and altitude. I was responsible for getting the shop's test gear in for calibration, and that was how I learned that the TTU-205 was worth about $80,000 at that time!

@tomschmidt381

11 ай бұрын

@@SkyhawkSteve Interesting unit, my memory is vague but that does not look like the unit we used. Back in those days much of the avionics gear was still vacuum tubes (valves for our friends across the pond). Most of our flightline repair was changing out the TACAN or or the biscuit pre A4F (a modified ARC27 UHF radio and APX6 IFF mounted to the cockpit bulkhead). VMA 211 ChuLai Vietnam 1967/68 my first tour and DaNang 1969 doing 2nd level ComNav rapair on my second. It was nice being in and an air conditioned space during the monsoon season.

@SkyhawkSteve

11 ай бұрын

@@tomschmidt381 The TTU-205 was a piece of yellow gear, and not what Curious Marc found. The TT-205 is still being made, and can be found in a web search. I've seen pics of the "biscuit" in the early Skyhawks. Looks like a pita to change out! We still had the vacuum tube ARC-51 UHF R/T in the nose on some aircraft, but the newer A-4M's had the solid state ARC-159 UHF radio that fit into the console! No need to crank up the nose! It was heaven. 🙂 I spent a few months with 211 at El Toro for OJT in '78. Kudos to the folks who served in Vietnam.

What is it? I don't know, but it seems dangerous. Okay, I want it!

It’s for testing minion loyalty, of course.

For testing air speed indicator and so on. Neato!

I want to see every detail ;)

looks robust and interesting :)

Altimeter calibration/simulation would be first thought. Some insects nested in a pitot tube once and caused bad things to happen.

Is it for ground testing calibrating static and pitot instruments?

@CuriousMarc

11 ай бұрын

Yes, exactly. Your altimeter, indicated airspeed, machmeter…

Where did you get the 3 Ph 400CPS 115AC from ?

@CuriousMarc

11 ай бұрын

Stole it from the Apollo setup. More on this in the next episode.

Pitot is the clue. Planes have pitot tubes to measure something, possibly altitude I can't rememeber. But that would make sense. So this could be for testing/calibrating your altitude measuring thingies?!

@CuriousMarc

11 ай бұрын

Yes! And the speed thingies too.

Since this was a British instrument, I assume you had to shovel coal into a small boiler somewhere on it...

@CuriousMarc

11 ай бұрын

And drive it in the left lane!

@nmccw3245

11 ай бұрын

And spill tea in it instead of coffee.

The case design was used for a number of different test sets, I have a missile test set in a similar case.

@JamesTK

11 ай бұрын

Need to ensure your personal missile stash is tested regularly

@SeanBZA

11 ай бұрын

Standard part at Smiths, who got it from Vero I think, as you had that design show up in a lot of avionics and military test equipment from the UK and France. Tough, rugged, and, most importantly, already certified in the system, with it's own NATO number, so you could use it and have a lot less qualification paperwork when submitting the design for review.

Interesting: add pressure via the hand pump to decrease pressure at the output and increase altitude... how does that work? Enquiring minds want to know! (And as an aside, I recently replaced an ancient paragliding variometer because while it still (apparently) showed the correct altitude, it would randomly decide I was going up when I was clearly going down and vice versa, complete with equally inverted audio signals. Bit rot in the PIC that did all the thinking, I suspect. Definitely not what you want.)

@SeanBZA

11 ай бұрын

Pump is double ended, in that one side of the piston operates as a suction pump while the other side provides pressure, with a set of one way valves and accumulators, so that it will do this on either up or down stroke, and then using electric power to operate the proportional valving, used to control the output manifold pressures.

@CuriousMarc

11 ай бұрын

Yes as @SeanBZA says, double ended pump, you use both sides, one for vacuum and one for pressure. Clever British engineering.

@neilbarnes3557

11 ай бұрын

@@CuriousMarc We do our best. If I'd stopped to think about it... thanks both.

Testing the pitot and static system? Just remember to pull heater circuit breaker before testing.

Ah! Of course! Until you started pumping I couldn't imagine how such a device would have simulated atmosphere at altitude. Clever.

@ShainAndrews

11 ай бұрын

Pressure decreases as altitude increases...

Simulating a fall from 50,000 feet at that speed was kinda scary, not gonna lie... 😅

Reminds me of that Elvis Costello song.

It's funnuy how much it resembles one of those "activity centre" toys for young kids, I guess we engineers are just big kids

@CuriousMarc

11 ай бұрын

We are kids, just with more expensive toys…

If my children were still babies then this would be far more fun to play with than the plastic garbage Fisher price sells. I think dad would play with it too. Nice toy, not sure why but I wish I had one😂

This is to test the gyro inside the altitude meter.

Looks like an artefact from the new Indiana Jones movie.

So you got another 'thing' fix the original thing, or at least to calibrate it now that it's been repaired. But the calibration thing also needs repair. That's a recurring theme on this channel. But I DO luv me sum a dat HP scopes and counters. 👍

@CuriousMarc

11 ай бұрын

Restoration within a restoration! And we were lucky, this is only two deep. Sometimes I have restoration within a restoration within a restoration! However when it gets three deep I am usually in deep doodoo and stop filming…

@EricLikness

11 ай бұрын

@@CuriousMarc I applaud how few times it "seems" you have given up, but I fully understand. There's only so much time and so many spare parts available. But with Mater Ken, Eric's magic finger, and Mike's ability to emulate and simulate (and untold others whose names I have not learned,...yet) CuriousMarc will fix and restore all the thingz.

My guess is that it is to test/calibrate the speedometer on airplanes that used pitot tube/air pressure/etc. to gauge the planes speed. Maybe altitude, too. Are used on boats, as well. Do I win a cookie?

@CuriousMarc

11 ай бұрын

Yes, altitude and speed instruments calibration. You sure are awarded a British cookie!

That reminds me of the Wizard of Oz twiddling knobs and generating bursts of flame after the screen is pulled away....

@CuriousMarc

11 ай бұрын

Pay no attention to the man behind the curtain! Or the guy that’s pumping…

@RobSchofield

11 ай бұрын

@@CuriousMarc 😆

I had the mercury filled one, with a separate vacuum pump that also allowed you, with suitable operation of the bleed valves, to test both altimeters and also air speed indicators, and to adjust them, using the handy screw hidden in the static port that adjusted the mechanical zero of the unit, so that you could then use the smaller front panel adjustment for barometric pressure to get the correct compensation for your local altitude pressure. Easy to set zero though, seeing as the official altitude for the base was zero feet anyway, and opening a manhole to work on anything you consulted the ATC via a phone call, to get the time of high tide and low tide, to see if you were going to be swimming in there or not. After being annoyed by a telecom tech with his pump trying to empty a manhole, I called the tower, and went to tell him to come back in 3 hours to fix the fault. When he asked why I told him to taste the water, which of course was salt water from the ocean, flooding in via the drain. Seeing as he had been pumping for nearly an hour, and the level in the small hole was not dropping, should have clued him in in the first place.... Plus the sizeable lake he was busy making on the concrete hardstand as well.

Guess if anything, can be used at home as a turbo wastegate tester ;)

@CuriousMarc

11 ай бұрын

Ship it to Clertus McFarland?

bendex time?!

@CuriousMarc

11 ай бұрын

Yep for testing our Bendix Central Air Data Computer

Chasing down Pitot/Static leaks can be a nightmare (ask me how I know :) )

@CuriousMarc

11 ай бұрын

And wait that the leak is actually in your tester. Aaargh…

@SeanBZA

11 ай бұрын

I did find the one static leak when I went to remove a pipe, that had apparently been there since assembly in Marignane, when it fell apart from corrosion, as soon as i tried to undo the flare nut. Went to the stores, and got a brand new pipe, first time anybody had ever ordered one in the stores history, and it had been sitting on the shelf since the 1960's. Put it on with something they did not use then, anti corrosion compound, on both surfaces and threads, as a very thin film, then wire locked it in place. Normally the rubber lines fell apart, but this was the first aluminium line I met that did the same. The rubber ones were a change on service item, just because of how badly they aged, but not as bad as the hydraulic hoses, which had a few emergency replace instructions on them for entire batches.

Cool score time to get that bender up and turning. Oh by the way you are not pumping you are sucking 😃

@CuriousMarc

11 ай бұрын

It’s a double action pump! It pumps and it sucks at the same time! Oh, the British technology!

@ludmilascoles1195

11 ай бұрын

@@CuriousMarc ah it both sucks and blows at the same time. OK got it 😂

looks like a verry complicated dead weight tester

@SeanBZA

11 ай бұрын

Dead weight tester is different, especially if you have the add on pressure transmitters to use with oxygen equipment, and the need to keep a 205l drum of pure ethanol around to fill it. Buying that drum of fluid every year was expensive, the excise duty was triple the actual cost of the ethanol inside, and you had to have 95.6% dewatered ethanol that was chemically pure, no adulterants in it, so it left no residue on evaporation. That was kept under lock and key, in a flame proof safe, and security did not have a key at all.

Neeto Pee Toe.

Just give it a thump with your finger

Guess what this is for? Looks like a midi controller that @LOOKMUMNOCOMPUTER would use.

@CuriousMarc

11 ай бұрын

Oh I love that channel. He can build a convincing music instrument out of anything!

Why no talking? 😃

@CuriousMarc

11 ай бұрын

The voice chip inside the thing must be broken?

@oetken007

11 ай бұрын

@@CuriousMarc 😂 Fair enough

first

@CuriousMarc

11 ай бұрын

You are! You are awarded free feeble British vintage germanium transistors.