I know I'm commenting on an old video but this is a really neat piece of antique kit and it's really interesting to see how precise navigation was done pre-GPS. Those germanium transistors are way cool, I love seeing transistors from the early days of solid state electronics.
There was a remote version of this panel which just has the left/right bearing display on it. Feedback isnt required on the bearing display, the operator set the display at take off to the known bearing/position of the airfield, then the system computed distance travelled and calculated the bearing using analogue electronics. Because the operator supplied the starting information there was no need for the system to intialize the display.
I love to see how things were done "in the old days". I never would have thought it'd be that simple to transfer a position. The ingenuity to create these mechanics and electrics (can't really call it electronics) is amazing!
Something neat I've realized with that synchro technique - since it's based on the relationship between the three waveforms, it'd be very forgiving of signal strength and noise. It would be very tolerant of wire length, for example.
Love your teardowns mate! Always having a blast when I get to take a good look inside an expensive or vintage piece of equipment. Thanks for sharing and explaining, keep up the good work! :)
The receiving end of a synchro is called a resolver. Do not drive the rotor on the receiving end. Instead, multiply it or synchonously demodulate it with the drive of the source synchro. The result can be driven into a DC motor that will drive the receiver to follow the source. There existed special motors than can be fed an amplified voltage from the resolver (and the AC power) and drive the resolver into the correct position. The direct drive as shown in the demo is for panel indicators.
Stepper motor might be easily used as an encoder. And, in fact, HAM radio enthusiasts were using them as a replacement for mechanical encoder. But now it became really easy to buy optical encoder. So probably it was possible to set the relative position with those numeric displays.
Great stuff, Mike. I really enjoy the under the hood look and speculation about devices and technology that go well beyond the consumer electronics realm.
I've always wondered what a resolver was. Some old CNC machines used resolvers rather than encoders on rotary axes to determine relative position. You can actually buy a board which will translate the output of the resolver to a pulse train that a digital system can understand.
+Ian Dodds nah I was just referencing other videos he's done with government electronics he purchased on ebay many comments saying how hard he would be arrested for owning outdated equipment.
+eumoria Roger that! Sorry! Not sure what he is whinging about. Surely military stuff is built to be resilient. I can remember computers, in the field, with ferric core memory. Solid and reliable, but large. :)
hi Mike - fascinating video! Do you still have this device? I'm really interested in the LEFT/RIGHT shutter on the main roller counter assembly - would you be able to make a video that illustrates the mechanism in more detail? like, I think it's driven by a gear on a shaft from behind, but I'm not quite sure. The reason is, I'd like to 3D-print and otherwise fabricate similar dual counters with LEFT/RIGHT shutters for flight sim and general amusement purposes.
400cy/sec is used on aircraft because 400cy/sec generator heads, motors and transformers are smaller than their 60cy/sec or 50cy/sec equivalents. Judging by the transistors and other parts I would say that the unit is of 1960s manufacture. The 1988 code on the display is probably from a panel rebuild.
Yeah I know - unless I've previously thought up an 'entertaining' ending, I usually just want to get it done & finished - must get around to doing something better....
Did you manage or even tried to put it back together? This engineering is art! Keep up these videos! You make me really miss not buying what I guess was a sixties vintage IR photography module from a military aircraft... The seller was nearly giving it to me, sick of all the guys that wanted to gut it for the lens, and had no clue about what it was, but that was hauling the damn thing via train that stopped me. Damn... Forever gone maybe, and that yardsale was in my ex Gf's town.
Did you ever do a teardown of your drone flight computer? I couldn't find it in a quick look through your videos. While I didn't seen a flight computer teardown, I did see lots of interesting looking videos. It's good to know there are lots of interesting videos I haven't seen yet.
I would guess, from the front panel, that it's some kind of VOR/DME interface. Not sure why it is labelled as a "Display controller" - it would have been very unusual to have any kind of visual output in the year it would have come from. Probably for military or commercial aircraft looking at the panel mounts (they are the same type as go in o/h panels).
Doppler navigator - independent of VOR/DME or anything on the ground except the literal ground itself. Tracks the aircraft groundspeed and drift angle with a radar. Compares this with the aircraft heading (from the compass system) and the pilot/navigator's desired track angle to integrate your movement towards your waypoint and sideways to your waypoint to show how far left to go and how far off-track you are.
The push buttons - each microswitch was certified for certain load, and certain number of connections, so by putting them in 2x or 4x, you just extended their durability and life. Old trick.
This might sound weird, but have you ever done a teardown of a multimeter? I can't help but think it'd be interesting. I use one several times a day, but really don't know what it looks like on the inside.
Love your videos, but I often end up with shaky cam syndrome when you yank bits of gear in all directions in front of the camera. Now excuse me while I go and hurl :)
distance to target or runway indicator - decca was the dogs b..... - at the time the miliary and the whole aviation industry used decca - sadly another great british firm that went to the wall
No, it’s not - it’s the “broad arrow” used as designator of government property in the U.K., and also used by extension as a bench mark for elevations on the ground confirmed by levelling to a conventional datum.
Dave Smith Tritium itself does not "glow" at all, it's just a source for Beta particles. You need a phosphor to produce light. Depending on the kind of phosphor you can create different light colors. en.wikipedia.org/wiki/Tritium_illumination
A quick look on Wikipedia. Electroluminescent displays have been around since the ‘60s (patented in the ‘30s) used by Chrysler on some of their high end vehicles for dash lights. Notably the Chrysler turbine car and imperial vehicles. These require fairly high voltage hence the 250v 400hz (400hz being aircraft frequency). Chrysler turbine used around 100v I believe. You can here the high pitch squealing of the boost converter to power the backlight. Other notable uses were the Apollo guidance computer display backlighting and of course this device we are watching. No tritium here. Light emitting capacitor LEC was another name for it.
