Etherwave Kit Extra parts

Hello,

After building my Etherwave standard kit, I had some extra parts left over. They aren't listed in the booklet so I was wondering what they are and if they are important

Pic here (http://img805.imageshack.us/img805/3170/img0224n.jpg)

The red plastic piece with hexagonal ends is a trimming tool, used to adjust the inductors.. it certainly is important.. keep this safe.. you are likely to need it!

Could you elaborate more on the red tool. Trimming to trim what? Wires? and Adjust inductors? Are inductors the knobs on the front?

And does anyone else know what those washers are for?

Plus the felt stripes that are to go on the feet of my theremin are impossible to remove from the paper that covers the sticky side. All that happens is the felt starts to rip off completely. Could I just glue the felt strips to the feet as is?

The 5 small washers on the right side are for the 5 screws which fix the circuit board. They are to be placed between the screws' heads and the circuit board. The small washer in the middle is to be placed with the screw which fixes the green wire on the aluminum foil. If omitted, the screw tends to break through the bottom of the housing.

The 4 big washers are for the 4 potentiometers (not inductors!) at the front panel, to be placed on the outer side between front panel and the nuts.

I don't know if these parts are really not mentionned in the instructions, but their use and placement seems self-understanding to me.

The inductors for which the red tool might be needed are on the circuit board. As long as you don't even know what inductors are, don't touch at anything! How could you consider building a theremin from a kit without elementary knowledge about commonly used components in analogue RF circuits?

Happy new year, Archez and Thierry! ;-)

Archez - To get the best from your theremin, it would be a good idea to read up a bit about the related electronics! You may find the http://www.moogmusic.com/manuals/HotRodEtherwav.pdf way over your head, but it will have some useful pointers.. Look up inductors on google - you will find they are essentially coils.. The trimming tool is for the VARIABLE inductors.. These are coils with a piece of threaded ferrite which one can adjust with the tool, these coils are contained in square metal cans on the circuit board, marked L1... etc on the circuit layout.. As Thierry says - DONT ADJUST ANYTHING ON THE BOARD - at least not untill you can explain to someone what a variable inductor does, and ideally can describe what a micro Henry (uH) is! ;-) Thierry's comments are valid.. Would you buy a kit car if you didnt understand what a wheel was?



Thierry - oh, I DO understand your frustration! I frequently get p*ss*d off by what, to me, looks like questions asked by people who are too lazy to get simple knowledge for themselves.. But we need to keep in mind the fact that science / electronics / mathematics, whilst natural to us, is not 'natural' to the vast majority of people on this planet.. I think it is sad - but it is true.. To most people, we may as well be wizards with majik wands and dark secrets!

The above facts hit me hardest at this time of year, when the Xtian world celebrates the birth of their god and ignores the fact that Jesus[i] [is recorded in the 'new testament' to have][/i] said he was not god (or the christ, or the king of the Jews)..They choose to celibrate their god as a helpless pathetic entity - a baby or nailed to a cross.. They chose not to celibrate the LIFE of Jesus, who was a radical MAN.. no celibration for him taking a whip into the temple and creating havoc with the bankers - No celibrating him instructing his followers "if you have 2 coats, and someone has none, give them one of yours!" - and I get mad when my children come home singing "weve got a great big wonderful god" having been indoctrinated by some evangelists (who in my opinion should be sent to jail) who visit their school. Bad enough having to swallow the inevitable deluge of Xmas carols without adding more BS to the catalog!

Sorry to go OT! ;-)

Fred.

Sorry to highjack this thread a bit, but...

Yes, Fred....to some of us, you and Thierry ARE wizards!

And yes, some of us are just lazy and some of us just don't "get it". I share the same frustrations on another forum I frequent.

As for me, I have a intuitive, working knowledge of horticulture that most people don't have. Granted, it took years of independent study and real-life experience to get there.

I've taken many electonic/electrical classes in college, such as AC/DC circuit analysis and electronic components, etc. and I've received an 'A' (grade) in all of them.

However, I still can't look at a circuit (physical or schematic) and really comprehend what is going on, except perhaps for a simple DC power supply. I couldn't design a functioning circuit to save my life. We can only speculate all the reasons why.

For some, it's not so easy to make the leap from abstract mathimatics to an intuitive, functional understanding of these seemingly "mysterious" circuits.

That's what happens to me too... I studied computer science so I have a good intuition of how digital technology works. I have no problem with logic gates, registers, processors, etc. But when it comes to analog technology, it might as well be magic for me. I have no idea of how anything more complex than a lightbulb connected to a power source works :/

I took a single electronics course at uni, where we studied RLC circuits and from the conversations about theremins in these forums I understand that they contain something similar to that (sorry if I'm inadvertedly saying technical nonsense). But I remember that analysing what a single RLC circuit was doing took a quite long while and required solving some differential equations. And here you typically talk about circuits that contain lots of different capacitors, inductors, apart from other things like variable capacitors and antennae, and you care about things like the distance of ones to the others, etc. which were abstracted away at my university course where one only worked with simple diagrams. So I feel that one needs to think at an entirely different level of abstraction to understand that.

Would people be interested in a thread here, where basic analogue circuits were discussed and explained?

I would be happy to participate on a non-mathematical (or extremely low level maths) level and simply describe circuits, and provide links to other (vetted) sites to compliment the 'course'.

I think others here would be able to put more 'meat on the bones' - and there is at least one other regular contributor here who has (despite not having english as 1st language) the ability to explain things superbly and simply .. Then there is Gordon who is astounding for being able to find meaningfull analogies for even my verbose ramblings.. ;-)

There was a time when I was hopelessly lost in real analogue circuit design - I 'designed' by pulling 'ready made' circuit blocks together.. I was fine with digital - could (did) design a complete visual display system for physiological waveforms using 74 series logic.. But when it came to the analogue side, was lost.. Despite having studied analogue for years.

One year of working with an analogue 'wizard' and I had got it - He (Jeremy Lord - Skywave Synthesisers) did not get me lost in maths or the like - he simply explained the circuits, and (more important perhaps) explained the mistakes I was making when I tried to design a circuit.. I think I reciprocated by making him better at digital design..

I believe that it is possible for anyone to understand analogue circuits - It only really gets more complex when one needs to optimise the circuit for production.

[i]"But I remember that analysing what a single RLC circuit was doing took a quite long while and required solving some differential equations"[/i]

The above is, I think, the root cause of the problem - No one should ever be exposed to an RLC circuit / maths until they know exactly what a resistor, inductor and capacitor are, and what they do! The concepts such as impedence are essential ... RLC is easy..... You have a resistor with fixed impedence regardless of frequency, you have a capacitor whos impedence decreases as frequency increases, and you have an inductor whos impedence increases as frequency increases.. Put these together and you get an impedence which varies with frequency, and has a point where the impedence of the capacitance and the inductance are equal.. Until you understand this, it is (IMO) folly to even look at the maths for the circuit.

I think some student for whom mathematics is a natural language, can easily work out how a circuit works simply by looking at the maths.. But for most students, maths is not a descriptive language, and does not help to describe circuit operation - and this is why many people get lost with circuit theory - it is not adequately explained in non-mathematical terms.

Fred

Can't understand why people often seem to be opposed to speaking "maths" although it is the most common and universal language to describe most of the things around us.

Is it perhaps the invention of pocket calculators which created this distance between people and their calculus? Now everybody can do complex computation by pressing some keys without the need to understand what really happens...

I think that the use of simpler tools like logarithm tables, slide rules, pencil, paper AND THE BRAIN would help people in a better connection between their mind and maths.

I personally like maths, I use them everyday in my job (it's discrete math what I use, not calculus, but I don't dislike calculus either). But I think the problem in my particular case was that the teacher didn't make the slightest effort to relate those RLC circuits to real life. As far as I can remember, he made a passing remark that those circuits were used in radio receivers, and that was all. So we could manipulate equations to calculate inductances, impedances, capacitances, etc.; but we had no idea of what all those things were used for. For example, I guess at the end of the course I probably had a grasp of what Fred has just explained about capacitors' impedance decreasing with frequency, etc. (I talk in the past and say "probably" because this was like 9 years ago and I have had no contact with analog electronics in the meantime, so I have forgotten most of it). But no one ever told me *why* one would want to have a capacitance that decreases with frequency, and the textbooks didn't say that either. So for me those circuits were an abstract entity that you could get some numbers from, but without any connection to the real world. So I agree with Fred... the math themselves were not the problem, but being exposed to the math without being exposed to what the circuits were actually doing definitely was, I think.

I personally would be very interested in a thread as described by Fred. That would be really nice.