Can someone give me an idiot proof tutorial on how BEST to do an internal tuning of Etherwave Standard?

I have to do this. Pitch field royally screwed because weather. It's been like 5 days since I've played since I want to learn new (advanced) repertoire. But I'm scared lmfao. I can play it, but I have to fiddle with it for a while after I turn the knob all the way counterclockwise with a very tiny pitch field and then play a bit . Then turn it clockwise and play a bit then wait. Then play a bit and turn it back, etc. Turn it even further clockwise. Until I get a playable pitch field with the pitch knob very far counter clockwise. This is probably bad for the instrument lol.
I have researched this, and I understand it is best NOT to touch L5. 

That said. Even though I am 99% sure I know what to do. (I'm smart, and I think I get it, but don't want to screw anything up, for example, I learned PGP encryption and even tho I knew what to do, I found a basically idiot proof tutorial WHICH was very helpful and took away any uncertainty -literally explain like I'm five)

Can someone give me a simple step by step idiot proof tutorial of how to tune a NEWER model of an etherwave standard. 
I actually have a multimeter that can measure frequency (hz) from something so that should be helpful, but there is probably an app for that now lol. 

I've quoted a method below for tuning the Etherwave that I saved a long time ago.  I can't find the original source for attribution but if anyone knows I will edit this post. 

Assuming your volume circuit is working correctly you should ignore the first part of the procedure.  I have followed portions of this procedure to recenter a pitch circuit that had drifted out of range of the adjustment knob.  Just knowing which inductor does what may help you correct your problem.  If however the tunable inductors have been touched previously then you may need to consider following the full procedure.

Some general tips... If you have an oscilloscope or frequency counter good for up to 300KHz or so available it is a good idea to measure your oscillator frequencies ahead of time before making any adjustments so that you can get back to where you started if you get lost.  That said, theremins have for a long time been built and tuned using only a voltmeter or even just by ear, and Bob Moog's original voltmeter procedure for tuning his theremins works quite well (Google it).

Also keep track of any adjustments that you make.  Add a little tape flag to the top end of your tuning tool (and only use a plastic hex tool, not metal) so that you can see the rotations that you make and so that you can reinsert the tool in the correct orientation if you must alternate between inductors.  Make a sketch of your starting positions and record each change so that you leave a trail of bread crumbs to get back to where you were if necessary.

I've updated and annotated the schematic to match the 11-211J version of the main board, but if yours is a different version it will probably be close enough.  You can download it from here. (Errata: C21 should be 4.7uF like C22)

If you are just trying to recenter the pitch range then L6 is probably the inductor to start with.  This controls the frequency of the "fixed" oscillator, which is the one varied with the pitch knob. A minor tweak of this will usually get the zero beat recentered on the knob, although you will have to keep slipping the cover into place to really check where you are as it affects the frequencies quite a bit.

L5 adjusts the variable oscillator (the one whose frequency is influenced by the player) and this is trickier because this oscillator frequency has to be optimized with the actual resonance frequency of your particular board and antenna (the components have tolerances) . The bendable wire running above the grounded patch of aluminum foil is there to give the user a small adjustment without involving adjustment of L5 as long as it is still properly calibrated.  If L5 hasn't been touched, try to leave it alone unless tuning L6 doesn't do what you need. 

And finally, remember that the cover must be in place for the final evaluation, and in fact the screws will affect things a little as well.  But don't replace the screws every time that you want to slip the cover back on to roughly check your tuning - you'll wear out the holes.  It can be a tedious process but as you proceed you will probably find that you will learn how far off the tuning should be with the cover off for it to be correct with the cover on.  I beat the system by building an identical "tuning cover" complete with embedded screws and access holes over the inductors.  But even that isn't a complete solution, because different wood affects the tuning a bit.

Use care, and good luck.  You can do it.

Here's the "Amos" technique for tuning the volume circuit:

Set the volume knob on the control panel to 3 o'clock. Stand as far to the right (pitch side) of the unit as possible, so you are away from the volume antenna. With the unit powered on and hooked up to amplification, reach over with the trimmer tool and start turning L11 through its range. Somewhere in the middle, you should hear a sound start to be audible, reach a maximum loudness, and then die off again. Turn the lug back to the point where the sound is loudest. This should put it in the correct range, to where the sound is silent when your hand approaches the antenna and them becomes louder as you draw away; additionally the Volume knob should be set correctly such that it controls not the actual volume but rather the hardness or softness of the volume curve; meaning how quickly the sound reaches maximum loudness as you draw your hand away. At the clockwise extreme it should have a brighter, sharper attack and at counterclockwise the volume should increase smoothly and slowly as you draw your hand away from the volume antenna.

Tuning the pitch circuit is really an art in itself. Roughly speaking, L5 controls the "top end" or the highest pitch you hear when you are touching the pitch antenna, and L6 controls the range, or how far from the antenna the zero point (zero beat, or silence) is located. I perform the tuning using a special wooden cabinet top with holes drilled above the variable inductors, because the presence or absence of the top influences the adjustments. It is more difficult when you have to perform the tuning with the cabinet top completely removed, and then listen to it again with the top in place to see if the tuning is still correct. Generally I find the top seems to influence the pitch downwards from what you hear with the top removed; if so in tuning it helps to "tune high" by a bit and then set the top in place to see if it falls into range. Here is my procedure.

First, listen to see if the pitch goes higher or lower as you draw your hand away from the pitch antenna. If it goes higher, adjust L5 so that the pitch descends through the zero point and then starts rising again; now it should be in the right direction. The next step is to grasp the pitch antenna and adjust L5 so that the frequency you hear is in the neighborhood of 3.8 kHz. L5 and L6 interact, so there will be a decent amount of back-and-forth between the two adjustments. Once you have the top end around 3.8 kHz, move your hand away and see where the zero point is located. It will likely be too close (too short a scale range); to adjust, stand at arm's length from the pitch antenna and reach over from the left to adjust L6. You want to adjust it so that the zero point is about an arm's length from the pitch antenna. Generally this involves turning the lug in L6 in the same direction as you adjusted L5 to get the top end.

NOTE: if the top is off the unit, you actually want to hold your right hand just about at the front edge of the wooden cabinet (~3 inches away from the pitch antenna) and adjust L6 until zero beat falls where your hand is, only 3 inches from the antenna. In my experience, this translates to about an arm's length when the top is put back on. The top kind of "stretches" the pitch field response by a large factor, which is part of why this whole tuning business is so difficult.

The first time you dial in zero beat, it will probably drive the top end higher than you wanted it to be, so go back to grasping the pitch antenna and turn L5 in the appropriate direction to get back in the neighborhood of 3.8kHz. Notice which direction it went (higher or lower) as a result of setting L6; and overshoot in the appropriate (opposite) direction to cut down on the number of times you have to go back and forth between the two adjustments.

"And finally, remember that the cover must be in place for the final evaluation, and in fact the screws will affect things a little as well.  But don't replace the screws every time that you want to slip the cover back on to roughly check your tuning - you'll wear out the holes.  It can be a tedious process but as you proceed you will probably find that you will learn how far off the tuning should be with the cover off for it to be correct with the cover on.  I beat the system by building an identical "tuning cover" complete with embedded screws and access holes over the inductors.  But even that isn't a complete solution, because different wood affects the tuning a bit." - pitts8rh

Roger, you are the king of fixtures!

Tuning the EW can be a bear, and if I had to do it more I might build a false / extra / tuning top too.  But I've found that just setting top upside down over the guts can give a good indication of how it will behave once properly installed and buttoned down.  This keeps you from unplugging and plugging the power brick DIN and so really speeds tuning up.

Another top stray capacitance compensation option I've seen here at TW but haven't experimented with: cut a length of stiff insulated copper house AC type wiring (around 6" or 8" or so?), bend it into a 'U', and stick that on the base of the pitch antenna.  Adjust the length to give you the same pitch as with the top on, then go to town with the tuning.

I really wonder how effective "grasping the pitch antenna" is in terms of accuracy / repeatability?  Might it be better to have a "dummy hand" C or RC to ground?  Cut a cheap alligator test lead in half and solder an NP0 C (or some RC).  Not all, but a lot of folks would be able to cobble something like that together.

If it seems that frequent access to the inductors will be needed then drilling access holes in the top might be a long term answer to prevent the hassle of constantly taking the top off and putting it back on.

(Obviously, best to take the top off initially to drill the holes...)

Apparently, it is possible to get plastic plugs to insert into the holes when not in use

There is a distance guide to hole placement in my photo folder 'Open Theremin' (I tried to link to it but don't know how to do it!).

This was given to me by Thomas Grillo and as I recall, he got it from Amos at Moog.

"There is a distance guide to hole placement in my photo folder 'Open Theremin' (I tried to link to it but don't know how to do it!)." - RoyP

Here ya go. 
To insert an image:
1) go to your media folder and click on the image that you want so that it appears full size
2) click on "original size" on lower right. The isolated image will appear.
3) copy the URL from your browser
4) in your "Post Reply" window click on the "insert an image" icon at the top (third from the right)
5) paste in the URL that you copied earlier from your media folder image.  Specify a reasonable width if it's a large image (I chose 900 px wide here).
6) press "Insert"
7) image should appear in your post.

BTW, these measurements should probably be confirmed on a given Etherwave before doing any drilling!

Thanks for doing that pitts8rh

BTW, these measurements should probably be confirmed on a given Etherwave before doing any drilling! - pitts8rh

It should be possible to measure the inductor centres with respect to the sides and back and relate them to the measurements on the diagram.
How does it go, 'measure twice cut once', or in this situation, 'measure three times and drill once'.
Obviously, if in doubt, don't do it.

I don't know about idiot proof, but if you have a frequency counter, here is how I would start off:

1. Take the lid off and make sure the wire from the circuit board to the pitch antenna is level and about as far away from the ground foil as it will go.

2. With the tuning knob centered, set the fixed pitch oscillator to 289kHz and the variable pitch oscillator just slightly lower.
    (Take a picture of how you routed the cable to your frequency counter, since that affects the measurement.)

3. Put the lid on and move the frequency counter to the audio output - get into your normal playing position - now measure the output frequency, and determine which side of zero beat you are on.  If you were really lucky, you'll be close enough to zero beat that you can just tweak the pitch knob and declare it tuned.

4. If you weren't so lucky, take the lid off again and tweak the variable pitch oscillator based on your measurement from step 3.  For example, if it was 500Hz on the wrong side of zero beat, tune the VP 500Hz lower.  If it was 1kHz, but on the right side of zero beat, tune the VP 1kHz higher.

5. Put the lid back on and repeat steps 3 & 4 as needed.