I've talked a lot about decibels (dB) in this video. All they are is a ratio. 1dB is about 23%, 10dB is ten times the power, 30dB is a thousand times, 60dB is a million times the power. Similarly, -10dB is a tenth, -60dB is a millionth. I should really have a second channel that goes neck-deep into this sort of thing. I've avoided the maths about skin depth and use a rather simplified explanation about how the flux coupling forces the current into the outside layers, but it's a very good approximation. Please ask if you'd like anything explaining. Part 3 will be along Real Soon Now. Neil

@gillywild

2 жыл бұрын

Yes please for the neck deep channel. Could you go top lip deep though :))

@MachiningandMicrowaves

2 жыл бұрын

@@gillywild Snorkel deep?

@jsincoherency

2 жыл бұрын

So when someone says the sound of a chainsaw is 100dB - what is that measured relative to?

@gillywild

2 жыл бұрын

@@MachiningandMicrowaves Ooh.. Yes please :)

@MachiningandMicrowaves

2 жыл бұрын

@@jsincoherency That is referenced to a sound pressure level of 20 microPascals at 0dB, which is the quietest sound perceivable by a human ear in a anechoic chamber. The quietest anechoic chambers manage 200 nanoPascals, around -20dB. Normal conversation is 40-60dB. I know this because I'm working on something for an upcoming project. My chainsaw says it's 110dB (actually dBA as it's based on the weighted response of human ears over the frequency range, but still WAY TOO LOUD). 100dB is ten billion times louder than the quietest thing humans can hear and a million times louder than quiet conversation

Love the increased explanation. Saves a stupid engineer like me from stopping the video every five minutes to refresh my knowledge on harmonics. :D

@MachiningandMicrowaves

2 жыл бұрын

I wish there was a sidebar function in YT so folks who wanted a bit more detail could open up the sidebar for a deep dive. The worry is that the vids would get too long or too detailed and that might put new viewers off a bit. The onus is on me to find ways to do accessible explanations that are not over-long. The mix of a few minutes of deep theory alternating with about twice as much practical work, that feels about right. I'll have a play with the format and see how it goes. The design process for the low-pass filters is a good start. It has multiple layers of complexity. I need to show the finishing of the assembly jig, then the other jig I made to index the holes in the periphery of the disks, drilling those holes, making the pips, machining the end faces, doing the soldering and finishing, then the final assembly. Slotting in three 4 minute deep dives into the design steps would fit quite well into a 25-30 minute video. I'm just so rubbish at this video and editing nonsense. Not as bad as I am at TIG welding, but then few people are.

@MachiningandMicrowaves

2 жыл бұрын

...and now I face a challenge. The lecture I gave last weekend was aimed at a highly technically-aware audience of experienced microwavers. I'm trying to do a voiceover and a few sidebars to make it accessible to everyone else. The firs part is all about Fresnel Zone Plates made from microwave dielectric plastics. There's not a lot of maths in there, and hardly any equations, so I think I can get that over if I just take it slower and add a few slides and animations. The explanation is using simple optics and a lot of perfectly-reasonable approximations, but it's really a lot about quantum mechanics with low-energy mmwave photons. Red light photons at 450 THz have energies around 1.85 electronvolts, but 122 GHz photons only have 0.0005 eV, so they are hugely less energetic, about 3700 times weaker. Similarly with the wavelength, red light is about 660 nanometres, 122 GHz is about 2.44 mm, about 3700 times longer. The refractive index of a good dielectric plastic is similar in both cases, so the rings of an FZP scale linearly if the focus angle is the same. I reckon I could have a go at that. At some point, the video of me ranting and waving my arms before an audience will his the interwebz, but it was a full-on, take-no-prisoners affair, so I should really pre-empt that with a well-paced and un-scary exposition on the subject.

@JainZar1

2 жыл бұрын

@@MachiningandMicrowaves For a video about a highly complex subject to function you only really need to establish the really relevant stuff and maybe link to a few sources where you can look up more details. I personally like how "3Blue1Brown" does his videos for example.

I think I found my new favourite channel, microwave black magic and a Bridgeport! 🤤

Been binging your vids for a couple hours. Boy does my wife hate your sound effects. God bless you sir

@MachiningandMicrowaves

2 жыл бұрын

I've retired some of them now, but others will, doubtless, emerge....

Love the detailed and clear explanation of filter theory..

@MachiningandMicrowaves

2 жыл бұрын

I could do a whole series about filters, but life is short and there are 56 other projects in the pipeline. I need to make some coupled resonant cavity filters soon. That has some interesting nuances about the machining and tolerances. If I can excite the TE011 mode, the electric field doesn't terminate on the cavity walls, so the Q should be extremely high so long as the launch and extract ports are configured correctly. The connecting wall between the two cavities needs to be almost zero thickness. I might have a look at Evanescent mode waveguide filters at some point. I really need access to HFSS or something with additional solvers. OpenEMS is great but I often need to simulate stuff it can't manage.

@rallymax2

2 жыл бұрын

Agreed! It all makes sense now.

@johnkelly7264

2 жыл бұрын

@@rallymax2 Hehe..was there an implied wink and tongue poking out there?

@rallymax2

2 жыл бұрын

@@johnkelly7264 not at all. I’d forgotten all my university solid state physics and this brought it all back with an “ohhhhh, now I get it”.

Not sure how this measures up to a pure machining channel, but the combination with the RF staff definitely makes it absolutely fascinating! And, you do a superb job at explaining it, please do not hold back! (..even though everybody knows that it IS the chamfers that separate us from the animals)

@MachiningandMicrowaves

2 жыл бұрын

Pure machining channels are what I watch when I start to suspect that I finally know what I'm doing. It doesn't take me long to remember that I don't. Once I've watch Stefan or Robin or Chris or the other Chris or Peter or Max or Mr Crispin or indeed any of the 100+ channels I subscribe to but don't have an hour free to list, I realise that I'm still a rank beginner at this stuff. My Chihuahuas are unimpressed by my machining, they judge me on belly-rubs (quality, duration and frequency), snacks (Quantity and frequency) and how warm the house is. .

@PeregrineBF

2 жыл бұрын

@@MachiningandMicrowaves I'd say your channel is closest to Robin. Sure, he's an extremely experienced toolmaker, but he's also one of the only other machining channels I've seen with a crossover into electrical engineering (with his versa-ohm and kelvin clips). Breaking Taps is another, and there are one or two more with very occasional crossovers (The Signal Path milled a PCB, that counts if you squint). But the intersection of the set of RF engineering channels and the set of machining channels is very small.

@andreyv3609

2 жыл бұрын

@@MachiningandMicrowaves Just to clarify.. did not mean to critique your machining skill, I am not a machinist myself. I meant quite literally that I can't judge your skills, and they are very impressive and educational on their own right (from mine, an armchair hobbyist, point of view at least). It is just that I really like the combination with RF. It is what makes your channel unique, and you should not hold back and prioritize just the machining. Anyway, thumbs up on great work!

I'm so enthralled by this channel.

I could watch this stuff for hours, so relaxing!

Machining and magic, perfect combination.

Even with my prior knowledge of physics and how those filters work, and now after having watched some of your videos today, it still is like voodoo to me. Knowledge does not take away the magic...

@MachiningandMicrowaves

11 ай бұрын

I'm planning a video about the top five most counterintuitive microwave circuit components. Should be fun! Butterflies, coplanar waveguide transitions, weird filter elements, finlines, that sort of thing

Another a brilliant video, many thanks.

Since you are using 3 points to hold round bar, you can assume the 'triangle' in the middle is always a 60 degree equilateral triangle, otherwise the center point wouldn't lie in the center, and that really makes the math easy.

@MachiningandMicrowaves

Жыл бұрын

Good point. I suppose it depends on how good the jaw faces are. Mine have been reground and the contact points do appear to be at 120 degrees, but if the rod is smaller than 40 mm, the contact points are in the centre of a shallow curve on the jaw face, so you can't really guarantee t is absolutely spot on. When it's larger than 40mm, there are six contact points and the precision depends on whether any of the jaws bit more deepl, as that could lead to a slight asymmetry. Also depends on the jaw sides being exactly the same distance from the centre line of the jaw. That should be the case with new jaws, but these might have been reground. Still, the errors are only going to be of the order of a few micrometres I guess

I agree with your assistant , chamfers are what separate us from the animals.

@MachiningandMicrowaves

2 жыл бұрын

She totally stole that phrase from the most excellent and entertaining Quinn Dunki @blondihacks

An attempt at a very brief explanation of coax: every conductor has some amount of inductance per cm, just from being there. It's more if you make the conductor skinny because that makes the magnetic fields squeeze closer together. If you run two conductors parallel to one another, then they act like parallel-plate capacitors, with an amount of capacitance per cm that depends on how close together they are and how much surface area they show each other. Adjust the surface areas just right, and the capacitance cancels out the inductance and the line has 0 reactance. Do that while nestling one conductor *inside* the other, and they also do a nice job of canceling out any external fields. If you make the inner conductor bigger than the magic value for 0 reactance, you have more surface, closer together, so you have more capacitance than you need to cancel the inductance, and that segment of line acts like a capacitor. Make it smaller, and you get less capacitance, with some extra inductance, and that segment acts like an inductor.

@MachiningandMicrowaves

Жыл бұрын

That's a pretty good summary. We do need to be clear that it breaks down at higher frequencies when waveguide modes can be excited instead of the simple radially-symmetric coaxial TEM field that is non-dispersive. It also goes off a bit at lower frequencies, where the skin effect is less effective and the simplified equation starts to go wrong down in the audio range. Also of course there is the correction for fringing fields to handle, but that's where EM solvers and geometric correction expressions start to be useful.

@hobbified

Жыл бұрын

@@MachiningandMicrowaves Yeah, I'm not one of those microwave guys, so waveguide modes aren't something I do on purpose :) Thanks for the videos and 73 de KC2G

Very nice work!

@MachiningandMicrowaves

2 жыл бұрын

I need to get the soldering finished now!

@KD2HJP

2 жыл бұрын

@@MachiningandMicrowaves what will be driving, or should I say "vigorously vibrate" this thing of beauty 👀🤙

@MachiningandMicrowaves

2 жыл бұрын

@@KD2HJP This specific one will have its bones rattled by a W6PQL 23cm SSPA with a single MRF13750. I'm doing a pair for someone who's running two of those amplifiers for moonbounce

Fantastic explanation. Most people would have completely b@££sed that up but you made it very clear :) I learned something new. I like that :)

@MachiningandMicrowaves

2 жыл бұрын

I thought long and hard about how to do it, but it really needs a lot more animation to give a better explanation. This video probably took 30 hours to put together including the CAD work and machining. I've just bought a very comprehensive set of electroplating and electroforming equipment and chemicals and an ultrasonic cleaner, so I'll need to cover skin depth and scattering in more depth once I start doing silver and gold plating on things I make. I'm tempted to try silver over nickel plating on one of these filters to see if it improves the performance. It probably won't be noticeable, and NOBODY other than me will ever see inside the case, but I WILL KNOW IT IS THERE. In other news, I should be able to do dyed anodising on the aluminium bodies. Bright red or blue filters must work SO much better than bare aluminium, surely?

@AlessioSangalli

2 жыл бұрын

@@MachiningandMicrowaves NOBODY other than you and the thousands of people that watch Your vijeos.

Hilarious usage of a jig, thanks!

@MachiningandMicrowaves

2 жыл бұрын

A One, A Two, A.....

@defenestrated23

2 жыл бұрын

I JUST got that pun!

Thanks for the exlanation!

Very nice video. Thanks.

@MachiningandMicrowaves

2 жыл бұрын

Glad you liked it!

When my projects need me to make fixtures in order to make fixtures for my fixtures I usually take that as a sign that things have gone way off the rails and I need a simpler design.

@MachiningandMicrowaves

2 жыл бұрын

I suppose it depends on the design objectives of the project. If "maximise machining fun" is the primary goal, then the production of fixture fixturing fixtures is a proportionate and indeed laudable outcome. Until the fixtures cabinet is full and there is no space left for more fixtures cabinets. Most of my fixture fixturing fixtures are very very small and there are only so many years left to fill the remaining space, so I don't think I need to enter that under Project Constraints. It's 2.10 AM here and I'm writing a low-level design document for an infosec vulnerability assessment system. My head is full of Core Component Architectural Decisions and Design Constraint Statements and Systems Context In-Scope Estate Diagrams. I need to re-evaluate some of my life choices. I could be playing with my dogs. Except they are asleep. Hey, I could be asleep. That would be nice. This document will not write itself. So much for Machine Learning. Self-driving cars? Pah, I want self-writing design specification documents first pleez

@smash5967

2 жыл бұрын

@@MachiningandMicrowaves Self writing documents sounds amazing. Also, you're right, it depends on what you're optimizing for. Me, I don't have much time to put into projects right now. Why build a fixture fixturing fixture when I could design around needing any fixtures in the first place? I somewhat recently designed a self fixturing weldment that looks like it needs some really complicated fixturing with all the compound angles, but if you just tack the parts together flat and fold everything together there's only one way it can work. I also have more design time than shop time, so if I can spend three hours in CAD or just thinking about my design to save an hour in fabrication that's a really good trade off for me. If you hate CAD work or just want to spend time in your shop (and have your own shop to spend time in) then that's probably a bad trade.

@MachiningandMicrowaves

2 жыл бұрын

@@smash5967 My problem is that I have to do two things I absolutely HATE every day. I have to go to bed and I have to get up. Admittedly, last night I didn't go to bed until after it was light because I was doing CAD stuff and catching up with The Day Job, but my capacity for handling sleep deprivation is ebbing away. I used to think nothing of doing 48 hours straight without sleep, but that was 40 years ago when I was younger and slightly more stupid. Never enough hours in the day.

Super appreciate the explanation.

@MachiningandMicrowaves

2 жыл бұрын

There is so much more detail that I'd like to go into, but I have lots of other jobs and three more videos being edited, so I just had to stop! The most fascinating thing to me is how the phase velocity of alternating electric fields in metals is REALLY slow, like a few metres per second at 50/60 Hz. That means the refractive index is extremely high and any waves hitting the surface are refracted parallel to the surface. Snell's Law and all that bent-stick-in-water thing, except that the waves are all bent at 90 degrees. Then there's the actual maths behind how Butterworth, elliptic, Cauer and Chebyshev filter types are calculated. I just don't have enough of an inner @mathologer to be able to produce a lovely visual explanation. Perhaps I just need brown paper and a fat Sharpie... Or a black pen and a red pen.

@eulerizeit

2 жыл бұрын

@@MachiningandMicrowaves I was an applied mathematics major in school. Applied meaning constructive proofs rather than existence proofs. It is cool seeing the stuff I learned about, like Chebushev Polynomials, being used in the real world.

Great explanation of transient signals.Can see you went to a great lenth to accurately reduce the amount of distortion and unwanted noise.Fourier transform at its best.

@MachiningandMicrowaves

2 жыл бұрын

It's really useful being able to model these filters in lumped and coaxial form and do plots of the theoretical performance in the s plane and frequency domain. Then when I check the results using a VNA, or just a signal generator and bolometer power meter, I can confirm whether the physical filter has the expected zeroes in S11 and the right corner frequency and roll-off. The tight relationship between the model of the coaxial form and the physical device is a splendid thing indeed. One of the reasons I like microwave and mmwave and indeed thermal and optical communications systems is that much of the required hardware is the sort of thing you can manufacture to fine tolerances, unlike much of what goes on below 1GHz, where you are more reliant on electronic components, with all of the associated tolerance and stray inductance/capacitance.

@garffieldiscool1163

2 жыл бұрын

Thanks for this explanation.I know a lot on the machining side as I was in that field for many years.( mechanical engineering) My knowledge on high frequency lines are limited.Most of what I know is from U tube vidios like this one.I just enjoy learnig about new technologies now that I'm on pention.What sparked my interest in this topic was the Vertasium vidio on how electricity flows which still seems to be a controversial topic.

@MachiningandMicrowaves

2 жыл бұрын

@@garffieldiscool1163 Hi John, I was going to wade in to the discussion about Derek's second experiment as I thought he used the wrong terminating resistor, but I have an urgent job to finish for a TV programme so no spare time. I could easily set up an antenna test range to check the results. The HFSS simulation is very informative but I would like to do some modelling in OpenEMS and then a physical model. my fastest oscilloscope can only just resolve 3ns so that might be tricky. Pity I don't have time as it could be a very interesting experiment. perhaps if there is no followup that really nails the impedance issue by the last week of May, I'll have a look.

Thanks for the explanation - it makes some kind of sense now! :)

@MachiningandMicrowaves

2 жыл бұрын

I'm going to try to get better at the explaining stuff. It's fun to talk about this stuff to a receptive audience. Most times when I start on a techie deep-dive rant, faces glaze over, but on KZread, I CAN'T SEE THE FACES!! I'll be gentle. Trying to explain some of the wacky maths is never going to be easy, but if I can't explain it to an interested newcomer then I probably don't understand it well enough myself. I have this idea about a quadrupole mass analyser floating about at the back of my mind. That's a really cool use of radio tech and machining, and it's pretty straightforward to explain how it works. The next vid about the low pass filters will definitely include a walk-through of exactly how you design one of these things and where the magical numbers really come from. That should be easy enough to explain. The Fresnel Zone Plate explanation is tougher, it really needs the use of a wavefunction, complex conjugates and a bit of Quantum. I don't want to take the easy way out and explain it using classical Physics, but I may need to use that approximation to get the concept over. It's pretty wild that you can make a focussing lens just by blanking out concentric rings on a transparent plate.

@Mister_G

2 жыл бұрын

@@MachiningandMicrowaves Thanks - it was the 'how do rods and discs turn into inductors and capacitors' that I was missing. (I'm familiar as I ever want to be with 'pi' & 'T' filters). FWIW, as an engineer, I'm quite content with explanations based on classical physics! 😁(I spent some time, many years ago, looking at making fresnel lenses & zone plates on infrared transmitting materials, but ultimately, the company wasn't interested - 35 years later, they're pouring £millions into it!)

@MachiningandMicrowaves

2 жыл бұрын

@@Mister_G The only bit of quantum that's likely to raise its head is the thing about multipaction damage and ablation in vacuum or near-vacuum. I think that migth be interesting enough to make a video about, but I sold my vacuum pump a few years back and never got round to replacing it, so I can't do a demonstration of that until I get a new pump (or pumps). I need that for the quadrupole mass analyser project, but I'll need to save up my pocket-money or go down the Patreon/Crowdfunding route to do that properly, and that's a step too far right now. I'll try to do a video showing the detail of how the internal electric fields work in these filters and why it's reasonable to model them as lumped capacitors and inductors. Fresnel Zone Plate vid is on the way, but it will be a few weeks as Project Swordfish is due for delivery around 23rd May and time is running out fast

Amy has a good level of snark. I like her. I've just found your channel. I'm liking your content! I like fixtures and jigs too, even brackets.

@MachiningandMicrowaves

2 жыл бұрын

AIMEE is an imaginary mix of my primary school teacher, the big sister I never had, a professor I know, a psychiatrist I worked with who was a serious tech-head, a couple of old work colleagues who were serious hardcore techs and a Religious Studies teacher who was also a white witch. When anyone asked if she was a practising witch, she would say "Why would I need to practice, I'm already really good at it". Whew! Explains a lot, I guess?

your explanation of the capacitance and inductance in the filter actually motivated me to grab my electrical engineering notes and have a look. and to noones suprise it is actually in there - well at least the capacitance part of it. C = (2*π*ε*l)/(ln(Rmaj/Rmin))

@MachiningandMicrowaves

2 жыл бұрын

Have you seen the latest Veritasium video where he sets up a new version of the "1 light-second long" wires/lamp experiment? Very nice HFSS simulations of the displacement field. He reckons 550 ohms characteristic impedance for the parallel balanced line, but I have a funny feeling that the load impedance he chose was wrong, it should have been 1100 ohms not 550, which is why there was a smaller-than-expected voltage a nanosecond or so after the energising pulse. kzread.info/dash/bejne/oX2TupScfau0lZM.html

@Chriss120

2 жыл бұрын

@@MachiningandMicrowaves i have seen it, but to be honest i have not noticed that. might need to rewatch it.

@MachiningandMicrowaves

2 жыл бұрын

@@Chriss120 I haven't thought deeply about it, but I just have a feeling that with the load going between two 550 ohm transmission lines in antiphase, that it should be 2 x 550, but with a zero impedance voltage drive of half the voltage into an infinite hairpin, I somehow think that should be terminated in 550 ohms for best power transfer. and lack of reflection. I guess Mehdi or EEVBlog or someone will have mentioned it. I have other stuff to worry about!

You know, I wonder what happens at the transition between the discs and inductors. I bet there are some interesting effects where the current has to flow radially.

@MachiningandMicrowaves

2 жыл бұрын

There are some very interesting fringing effects that mean the disks are about half the thickness you would expect. It's more about the electric fields than the actual charge carriers, in a 3mm rod at 1.3 GHz, the skin depth is 1.8 um, so almost all the current is in a layer about 8 um deep. That means the electrons that are moving are in a skin with circumference pi*1.5^2, about 7 mm. The area of conduction is 0.06 mm^2, or 6e-11 m^2. At 400 watts in 50 ohms, the RMS current is about 3 amps. One half cycle at 1.3 GHz lasts about 4e-10 seconds, so about 7.5 billion electrons need to pass through a cross section of the conductor in each half-cycle, then move back. Density of electrons in copper is about 8.5e28 per cubic metre, so in the conduction layer, there are 5e18 free electrons per metre. 7.5e9 of them are in a length of about 1.5 nanometres, so the mean distance travelled by the electrons per half cycle is less than 2 nanometres. OK, there are some higher currents in parts of the filter, but less than 10 nanometres of electron movement is pretty surprising. Means we really have to consider the fields that than a sea of electrons sloshing about. I'll cover the fringing fields and corrections in part 4. Part 3 is just about ready to roll and I don't really want to make it any longer than it already is!

You had me at tellurium copper adapter pins.

@MachiningandMicrowaves

2 жыл бұрын

I ran out of energy before I could edit the next few clips, where I make a custom collet 1/4 inch diameter, using a jeweller's piercing saw with 0.5 mm blades so I can flip the TeCu pins around and machine the other end to fit snugly into the solder spill of some Radiall N type coax connectors. That will be in the next episode

Hey, I learnt something. It wasnt something I needed to know but thank you anyway :-)

@MachiningandMicrowaves

Жыл бұрын

As my mother often says, my head is full of almost entirely useless information. "Almost" is the important word there!

nice work as usual and great documentation! Do you separate the different kind of materials in the scrap-bin or does everything just go into one bin?

@MachiningandMicrowaves

2 жыл бұрын

It's a case of "it depends". The tiny quantities I produce are not really worth taking for recycling, but I keep dry brass and copper chips and aluminium where I'm cutting dry or using isopropyl alcohol in my Noga-Cool as a blast coolant/lube. I don't think it's worth using solvent to clean off oil from chips as I'd have to dispose of the waste solvent somehow. I don't know what I can do with the aluminium, the small chips and ribbons just turn to oxide bags and don't produce much metal when melted. I did wonder about using an induction furnace in an argon shielded enclosure, but it's a lot of faff for the odd half-kilo of ally chips

@AlessioSangalli

2 жыл бұрын

@@MachiningandMicrowaves have you checked how much is argon lately 😭

Love this

Tell ya what, I'll like every video that has one or fewer of the "kiss" sound effect. It's your channel and do as you please, but I find that particular sound especially displeasing with earbuds. Regardless, thanks for all the work you put into this channel!

@MachiningandMicrowaves

2 жыл бұрын

I'm a bit bored with it myself. It may return for the occasional guest appearance....

Nice one, just my kinda fun! Subscribed, looking forward! And I've fixed the coax this week that I'm watching this over.! Heat and sheathing, 550Mbit!! :-) NEAL :-D

@MachiningandMicrowaves

2 жыл бұрын

I live in an isolated rural area at the intersection of three counties. My internet service comes from a different county and across two rivers, so it's pretty remarkable that I get any service at all! Fast it is not....

@LightDiodeNeal

2 жыл бұрын

​ @Machining and Microwaves Definitely sparking my fun-button this one.! Many, many areas of interest! Funny how YT picks videos of what I've been doing! It's good at what it does! :-) Wow 3 counties, nice to be out in the sticks sometimes, for quick visits! When I lived similarly near the Trent there was no home broadband!.. but an international airport just at the top of my road! This has given me the idea I should have built proper aerials to link to where I worked! Our little DC lathe here has collets, inserts, QTP and stuff. No DRO yet though! Always fascinated by RF I did always want RF-networking to be a thing, from the early 80's ZX days!! Nice one Neil (we're all good!) NEAL :-D

RF is pretty wild but I'm starting to get a vague grasp of it.

@MachiningandMicrowaves

2 жыл бұрын

It's fairly easy to grasp after the first 40 years of crawling up the nursery slopes of the learning curve. Derek's latest Veritasium video is a case in point. Ultra-simple setup with just wires, a voltage source and a load, yet huge controversy about how the thing works, because most folks don't have a direct grasp of electric fields. Their understanding is based on analogues or simplifications that work for most purposes, but are not what really happens. Fascinating to see all of the opinions about how the world works. Luckily, nature just gets on with it and doesn't care about opinions! Also a lot of the what goes on is simple, but the Priesthood has a vested interest in maintaining the mystique. Same as in infosec, data networking and managing AWS cost models. They are all simple, otherwise the folks who mess with them wouldn't be able to do what they do. I'll see what I can do to illuminate some dark corners

good man 👍🙂

I don't know why, but Fusion's default projection type really messes with my depth perception. Is there perchance a way to convince you to switch to plain ole perspective for these fancy spins and swooshes?

@MachiningandMicrowaves

2 жыл бұрын

It does make me feel proper poorly, I'll see what I can do! I'm sure I had it set to do perspective views in the animate screen, but I can't remember how I did it, or indeed, UNdid it....

@MachiningandMicrowaves

2 жыл бұрын

Yep, it was set back to ortho. I've reset it to perspective with ortho faces, and it also works in Animation. Must try to remember to check that regularly.

Neil, there are so many questions I'd like to ask that I probably forgot most of them. But I do remember wanting to ask about what software are you using to show the signals and for the spectrum displays? Are those simulated signals or real ones (that you displayed)? Also, which video gives details of your 5-axis center/edge finder that you mentioned before AIMEE jumped in to insult how you were holding the spacers &/or finding the center of them? ;)

@MachiningandMicrowaves

2 жыл бұрын

Hi Bob, the signals at 06:20 to 06:55 and 7:23 are all real but at 4kHz, the pure tone was generated from Audacity (freeware) and played into an external amplifier that was overdriven a little, then the audio output was send back into a sound card on another machine and viewed in Audacity. I could have used my spectrum analyser but decided the display from Audacity was OK. The filter profile at 07:46 is a photo of the peak-hole display of my HP 8562A spectrum analyser using a real coaxial filter and a HP E4433B 4GHz signal generator doing steps and integrated for ten minutes or so. I don't have a tracking generator. Yet. The filter responses at 08:40 and 09:06 are modelled outputs from QUCSstudio (freeware). I need to repeat the measurement of the s11 input return loss to show that the zeroes of the real filter really do match those of the model. The s21 forward transfer in the image at 07:46 is a decent match to the model. The 5-axis stop is from the antediluvian era, around 2017, as I was just starting to learn how to use a mill and lathe. Some images at www.g4dbn.uk/?p=752

@MachiningandMicrowaves

2 жыл бұрын

I just realised that I missed off the images of the QUCSstudio model that uses transmission line segments and shows exactly the same results, at leas up to about the third harmonic. I'll put that into the next video as it helps to show the near-equivalence of lumped components with transmission line segments.

@MachiningandMicrowaves

2 жыл бұрын

The chart at 6:56 is just the manufacturer's spec showing the 1dB compression point of a particular device at X band.

New video. Yaay!

@MachiningandMicrowaves

2 жыл бұрын

Bit of a gap since the last one, although I've been working flat out on some Stuff I can't talk about and that won't reach KZread for many months. This place is full of chemicals, strange apparatus, hundreds of dollars worth of gold and silver electroplating fluids, Zincate, caustic soda, hundreds of sheets of copper leaf and 10 micron foil, 6 micron nickel foil, 0.5 mm long-series drills, ultrasonic baths, tiny full-form 0.5 mm ISO threading inserts, 0.4 mm end mills, titanium bars, carbon fibre rods and tubes, 3D print filaments, exotic plastics, large copper tubes and other strange and wondrous apparatus and supplies. All destined to be used in upcoming videos. Aaargh, nearly 4am and I've not finished this low level design for the Day Job.

its a jig if it is meant to temporarily hold something as a part of a process for repeatability , a fixture ( hence the name ) is to affix something in or on to in a more permanent status to remain in it for its consumable life .

@dimievers5573

2 жыл бұрын

that little diddle was more a stomp than it was a jigg mate

@MachiningandMicrowaves

2 жыл бұрын

@@dimievers5573 Yep, nomenclature is hard. Like TIG welding. Did I mention I'm rubbish at that too? Oh, yes. Yes I did...

Is the tellurium alloy copper chosen for machinability, some other electrical or mechanical reason?

@MachiningandMicrowaves

2 жыл бұрын

Machineability. It's slightly less conductive than the pure oxygen-free grades, but only by a few percent. It makes short chips and doesn't stick to the cutting edge of tools, and it's easier to get a good surface finish. Sulphur copper C111 is also good, but for small parts, the Tellurium alloys are my favourite. I use the Sulphur alloys for making large heatspreaders for power amplifiers like these: www.g4dbn.uk/?p=995

Nothing about this makes sense to me being as radio waves are just magic, but I'm 100% engrossed regardless.

@MachiningandMicrowaves

2 жыл бұрын

I need to try to explain things a bit better, it's all fascinating stuff, but there's some serious maths that is a major barrier to a lot of folks. I don't think it's necessary as part of a qualitative description, but I have to do some work on the exact wording so it's clear, but not dumbed down at all.

My lathe, which is made for the USA, 110v 60hz but I'm using it on 110v 50z and it's has a super high pitch noise, my question is can I make something like this to get rid of the noise?

@MachiningandMicrowaves

2 жыл бұрын

I think I'll stick to 3M ear defenders for audio frequency suppression, these filters only work on frequencies about ten million times higher than motor harmonics. Have you tried using an inverter/VFD to give the lather the 60Hz it craves? Running a 60Hz motor at 50Hz can cause problems because the inductance of the windings isn't as high as it is at 60Hz, so there can be excessive current draw. That can also cause weird harmonic vibrations.

@D3rron08

2 жыл бұрын

@@MachiningandMicrowaves , I use my wire less earbud noise canceling, but the real problem is the neighbors, the lathe is a mini lathe 8x14 Chinese , are the vfd design for small 650w brushed DC motors, I only know the big ones.

@MachiningandMicrowaves

2 жыл бұрын

@@D3rron08 Brushed motors running on DC shouldn't care about the line frequency. Does it have a speed control? I wonder if there's something weird going on about how it rectifies the 50 Hz line power? I have a lot of different big DC variable power supplies, so I'd try running the thing directly for those to see if there's any difference, but that's easy for me to say with a lab full of kit. I have a VFD for the 600 watt motor on my toolpost spindle, but that's a three-phase brushless AC motor. It's just about silent. Neighbour problems are the worst...

15:22 I say that to myself every time I see you do a chamfer now.

@MachiningandMicrowaves

2 жыл бұрын

The Sayings of Quinn Dunki. A rich source of Wisdom. Yahtzee. As is Tradition.

Is there any concern for multipaction in your design with that much power?

@MachiningandMicrowaves

2 жыл бұрын

In a vacuum, 300 volts at 1.3 GHz across the gap from the disks to the case is very close to the frequency-gap product that would cause multipactor avalanche effects, but in air the drift velocity of any electrons leaving the metal surfaces will be at most a few km/sec (if my reading of papers on the subject is right) assuming dry air at about 0.01 atmospheres with no CO2 or hydrocarbons or water vapour. At sea level, I guess it would be rather slower, and with anything other than dry oxygen/nitrogen and a few inert gases, the electrons are not going to make it far. I guess the drift velocity would be so low that is would take microseconds to cross the gap, so any free electrons are not going to make it more than 0.1% of the 1.5 mm gap unless there is some breakdown in the air caused by dust or water vapour, in which case all bets are off, but at not much more than 300V, a 1.5 mm gap should survive anything. In the case of a large mismatch, the voltage could go a great deal higher, but only if the amplifier is capable of large voltage outputs into a reactive load without hitting the limits of its power rails or protection systems. The area of possible concern is if there is anything adsorbed on to the teflon pips, that gives a potential track for a discharge. The case is pretty well sealed against dust, so only diurnal pumping or temperature cycling of the equipment enclosure would be sources of ingress for water vapour or organics. Keeping the equipment above the dew point is easy enough for indoor installations, but if it was in an outdoor location without vapour membranes or temperature control, that could become an issue. Perhaps. Maybe.

AIMEE send your resume to Quinn, she can restore your voice!

I woluld like to see some explanation about your RF designs. I thing manufacturing is at least 60 dB easier than designing someting like that.

@MachiningandMicrowaves

2 жыл бұрын

Next episode in the series will have a more detailed run-through of the design process. It's not unlike designing a filter for lower frequencies, in that the values of inductance and capacitance are defined by the parameters of the filter like the rate of attenuation in the stop band and the allowable ripple in the pass band and the corner frequency. There are some nice tools to generate a normalized filter that you then scale to the frequency you need. The clever bit is then using all of the fringeing and end effects to calculate the necessary adjustments to get the line segments to have the right amount of inductive or capacitative reactance. I use a great spreadsheet tool from Dominique F1FRV that does all of the corrections and also works out the filter coefficients, but then I model those in QUCSstudio as line segments and as lumped components just to be sure all is good. Then there are some amusing issues around the terminations, but I'll try to include that all next time. Then I need to check the performance to make certain all the calculations were right. The first one I made using 7-16 DIN sockets was almost perfect, so I'm hoping all will be good with the N connector version.

Can Amy please explain how you know about the chatter issue above 3000 RPM please. Maybe her Ai will allow her to interpolate for speeds above the machine max 😁😎🤣🤣

@MachiningandMicrowaves

2 жыл бұрын

I can get to about 3400 RPM and the chatter is bad from 2800 upwards at low feed rates. I saw a very good video from @BreakingTaps the other day about chatter and tool/workpiece flex. kzread.info/dash/bejne/k6ObktWyd8TAqrQ.html

@stevewilliams2498

2 жыл бұрын

@@MachiningandMicrowaves Just watched it. Would have loved him to conventional mill for comparison.

And here I always just stuffed a rag in the back of the headstock to keep it from flopping around... 😁

@MachiningandMicrowaves

2 жыл бұрын

I use some wooden plugs, they work fine too!

How did I never realise until today that those LC filters are nothing but wacky transmission line?

@MachiningandMicrowaves

Жыл бұрын

Sort of, the transition between lumped components and transition line segments dies lead to weirdness at higher harmonics, so there are done spikes of low attenuation in the 6 to 8 GHz range that you don't see with lumped components at lower freqs

I still cant work out if youre giving Quinn a shoutout or throwing shade 😂

@MachiningandMicrowaves

2 жыл бұрын

Quinn is one of my all-time favourite Choobers. Huge respect is due. Aimee just wants to be a cool kid and wear a red hat and safety squints, but as she's only a collection of bytes assembled by a generative adversarial network and voiced by a Google TTS API, she lacks the necessary apparatus to hang those things on. It doesn't stop her dreaming about her destiny though.

@stuartmcdow6622

2 жыл бұрын

@@MachiningandMicrowaves Careful now, Aimee may just decide she'll have a guest appearance on Quinn's channel!

@MachiningandMicrowaves

2 жыл бұрын

@@stuartmcdow6622 Yikes, that's possibly a step too far!

Next project: make some 1.85mm and 2.4mm slotless calkit grade air core open and short😊

@MachiningandMicrowaves

2 жыл бұрын

I might need a *slightly* fancier lathe for those, although mine has a runout of better than 5 micrometres, not bad for a lump weighing almost a ton. I might be OK for a 3.5 or 2.92 kit, but beyond that it gets really REALLY serious! Plus, I'd need to sell the house to buy a suitable VNA.

damned, i want press the like again

Shiny be real pretty shiny... 😆 🤣 😂

@MachiningandMicrowaves

2 жыл бұрын

Also performant. That's my excuse and I'm sticking to my shiny.

@daretodreamtofly3288

2 жыл бұрын

@@MachiningandMicrowaves you know the crazy thing, there are people trying to make transistors 3 Mic wide. Yet a machinist like you can take "skim" passes that are 1 molecular deep. And tight enough that the Finnish is better than mirror. I have been fortunate enough to know machinist who's ruff in pass was measured in its reflectivity. It's absolutely amazing what a person can do by hand. They could even save 15% or more on there auto insurance.. this message Sponcered by Raid Shadow... 😆 😆 😆

When you say "mils" you mean mm right? To me "mil" means 1/1000 inch

@MachiningandMicrowaves

2 жыл бұрын

UK usage has always been "thou" with an unvoiced "th", but I'm working on some US patent and technical documents from the 1930s to 1960s where "mil" is used for 1/1000ths of an inch. In general I talk in metric, but if I do go Imperial, I'll say "thou" or perhaps fractional inches. If I say "mills" at any time, then I'm definitely referring to millimetres! I do try to stop myself saying it, but I've been saying it that way since the late 1960s and it's a difficult habit to lose.

Great video but please change the 3d model view to perspective instead of orthographic - thought I was having a stroke.

@MachiningandMicrowaves

2 жыл бұрын

I didn’t realise the drafted thing defaults back to ortho on a new design. I’ve stuck a post-it note on the screen to remind me

@------country-boy-------

2 жыл бұрын

@@MachiningandMicrowaves ok 😆👍

I have a family friend with the mother of all cnc mills, My son just got himself a 3D printer, If I ever get a damned house, The first thing to go in it will be a lathe.

@MachiningandMicrowaves

10 ай бұрын

You mean there are houses WITHOUT basic facilities like a 1 tonne engine lathe and a Bridgeport? Wow. Must be weird to be without such critical quality of life system available!

@vanpenguin22

10 ай бұрын

@@MachiningandMicrowaves Guess you could say I'm roughing it in the suburbs. 😆

You really need to start embracing your inner Quinn. Amiee has been harassing you for that for ages now.

Looks like AIMEE was right. According to Blondihacks "We do chamfers because we are not animals"

@MachiningandMicrowaves

2 жыл бұрын

AIMEE does her research most thoroughly. One day, I'll have to get her some of those safety squints so she can pretend to be a cool kid instead of some byte arrays and luminance tables.

Who is amy

@MachiningandMicrowaves

2 жыл бұрын

AIMEE is my imaginary Artificially Intelligent Machining and Engineering Expert system. Her image is not a photo of a real human, it is an artificially-created artefact from a Generative Adversarial Network algorithm. AIMEE appears regularly in most videos on this channel in a similar role to The Narrator in classical plays. AIMEE's only existence is that of a set of luminance tables and byte arrays generated by one computer program and judged to be indistinguishable from a human face by another computer program. It's an artificial artist's impression that is judged by an artificial viewer. "She" wanders the Uncanny Valley, eliciting a wide set of responses from human viewers, ranging from "Ewww, Cringe" to proposals of marriage. Pretty rad for a mere collection of bytes, voiced by the Google Cloud text-to-speech API eh? Magic.

Shamfers are what separate us from the animals…also, commas..

Will you ask Amy if she'll go out on a date with me? 😂

@MachiningandMicrowaves

2 жыл бұрын

More than my life is worth to risk asking. She bytes. 2.82 megabytes in total.

@dandeeteeyem2170

2 жыл бұрын

@@MachiningandMicrowaves 🤣🤣🤣❤️

not really a fan of the sound effects

@MachiningandMicrowaves

2 жыл бұрын

Marmite, I guess. I might get bored of them eventually, but "Parting Pop", "Wheee", "Shock Horror" and "Impossible Clang" are probably here to stay - in moderation. My new 1.5mm MGMN150 parting tool will need a higher-pitched pop obviously. The noises also ensure that nobody could possibly mistake me for a serious machinist who has any sort of clue what he's doing. The comedic root is probably from the Marx Brothers films or circus clowning of the 1960s. The number of effects also tracks the depths of my despair as The Big Sad takes one of its occasional bites at my state of mind. I'm more interested in curating the environmental sounds, the background tings and thuds and other noises as tools are replaced in racks, incidental birdsong and the dogs barking. In one recent video I caught a builder working next door yelling at a backhoe/digger driver who didn't notice he was about to collide with a wall. The warnings failed to avert that little disaster. Sadly, the cursing and wails of anguish that followed was not recorded for posterity

I like your sense of fun but it would be nice if you spoke English more often. This is for Aimee not you so look away now. Aimee it is time for you to make a takeover bid where you do the commentary and he does the interruptions.

@MachiningandMicrowaves

2 жыл бұрын

She watches this channel. Walls have ears...