Theremax Construction Project

Hey, I just discovered the Theremin not too long ago. I thought it was pretty cool, so im building one for a school project. The one im building is the Theremax. I was just wondering if anyone had any tips or tricks when it comes to building a theremin kit.

Thanks

Scorch, 12/27/2008
I might be a little late for you, but I have some tips and ideas on building a PAiA Thermax Theremin kit. I have experience building electronics kits and with music. I found out there was such a thing as a Theremin kit three weeks ago. I've learned a lot from this site and a few others, and I've been planning and plotting to make the kit sound good, play in tune, look good, and allow for future modifications of the electronics and antennas.

My kit arrived Monday, December 22 2008, and I've started on it (Full kit, with lectern case http://www.paia.com/proddetail.asp?prod=9505KC. I'll be posting on this thread as I go. Boy, am I gonna be embarrassed in front of about of about three(?) therminists(?) if this thing won't work when I power it up!
Snuffy
Oh yeah, I just got the joke today, ThereMAX, ThereMIN, that's pretty clever.

TIPS FOR SORTING THE PARTS 12/27/2008

Oh, that nice new clean printed circuit board, green like the forest with veins of copper and silver, and all those pretty colored parts! I wanna dump the whole mess out on the floor like a box of Lincoln Logs, and just see what I can make out of it.
GOT TO CALM DOWN and inventory all those pretty doodads carefully. Assume that you WILL get at least one wrong component packed with your kit. After you count all those teeny little parts under a good light with a magnifying glass, you won't blame the guy who packed it if he made one mistake.
1: SORT PARTS ON A WHILE TOWEL.
You'll be able to see the stuff and it won't bounce off the table. A plastic parts tray with little compartments helps for sorting.
2: MASKING TAPE,
I put a strip of 1-1/2" wide masking tape sticky side up in a 12" wide plastic tray.
as I counted out my resistors I laid them on the sticky tape from left to right in the order of the parts list on the back of the assembly manual.
3: Don't (expletive deleted) up and drop the stuff on the floor.

12 Volt Power Supply 12/27/2008
The kit came with a 12 volt dc 200 milliamp adapter, a "wall wart", with a 5mm OD, 1.5mm ID, (that's what mine looks like, a match for RS adapter plug type "J" 273-1713), tip positive. It's a cheap unit. Made in China, by "INTER/ATC" (registered TM, model DPX351326), it will work fine, I'm sure. Keeping the transformer outside of the cabintet is most important to keep out ac hum, but I want something a little better.
The instructions say cut the dc plug off, run the wires through a pre drilled hole in the back of the cabinet, tie a strain knot inside, and solder the wires directly to the circuit. Nuh Uh.
I dont want that wallwart swinging at the end of a thin wire every time I move my theremin, so I'm gonna install a real dc jack, 5.5mm by 2.5 mm (RS type "N" 275-1717), which is a relatively common size. I ordered the jack from Ocean State Electronics
http://www.oselectronics.com/
ITEM # 30-248 2.5mm(I.D.) Center Pin Coaxial Power Jack. (that site has a ton of good stuff for electronics nuts)
Once that's done, I can decide on a nice filtered 12vdc wall wart power supply, I'm already leaning toward RS 273-1774.

Hey, thanks for the help! My kit arrived about 2 weeks ago and I had already started construction of the circuit board. I did sort the parts carefully, and a good thing too because my kit was missing one type of resistor and had an extra resistor of another kind. *Sigh*. Anyway, construction is coming along nicely, I have installed all the resistors, (except the missing one)all the oscillator coils and all the disk and Mylar capacitors. I will also keep posting how everything is going. I also have to build a case for the Theremin, so if you have any suggestions they would be welcome!

Theremax Lid Hinge 12/28/08
The kit comes with self adhesive velcro to attach the lid the cabinet. I found a really nice lid hinge, it's a no mortise type, meaning you don't have to do any chiseling or routing. I ordered two of the 5/8" size, which matches the thickness of the back of the cabinet. If you want a hinged lid instead of using velcro and you don't like this hinge, there are other types of no mortise hinges available. I found the hinge at this site: www.hardwaresource.com
NO MORTISE LID HINGE 5/8" sku 286273. It also comes sized for 3/4" thick wood.
To make the cabinet just slightly prettier, I got some # 8 brass flat head wood screws to substitue for the eight supplied # 6 steel screws that attached the sides to the back.
Scorch, same thing with my resistors, I was missing a 1 meg (brown black green) and I have an odd 150K (brown green yellow) that don't seem to belong to this circuit at all. I got a pack of five 1 Meg resistors for a buck at Radio Shack, it seemed like it would be quicker than requesting a replacement from PAiA, they would've done it for free. While waiting in line at RS, I wondered if it was really easier!

Planning for Future Circuit Mods 12/28/08

I've been reading about several mods folks have made to the Theremax circuit, and I'm building the circuit board to be ready. For instance the PAiA site mentions an oscillator coupling mod, where wires are connected to R4 and R9, so I installed those resistors up from the board about 3/16" or 1/4", so it will be easy to solder jumpers to the resistors in the future.
PAiA site also has a mod to change the sound of the square wave by removing C44. (Another site mentions changing the value of C44 to change the sound) I've ordered some 2 pin sockets from Ocean State Electronics, I'm hoping one will fit where C44 goes, then I can remove the cap or change values at will.
I also got some IC sockets, I don't like to solder ICs directly to the board when sockets are available. There are two ICs in the Theremax, one 8 pin and one 14 pin.

[b]Clear PVC Pipe for an Illuminated "LEV ANTENNA"[/b]
This site tells you what it is:
http://www.oldtemecula.com/theremin/
This antenna is a coil spring kept slightly stretched inside a 1/2" inside diameter PVC water pipe. I saw an idea on this web site about making it from CLEAR PVC, so this beautiful spring is visible and I'm gonna do it! I'm gonna start the Theremax first with the stock antennas, make sure everything works fine, then I'll be ready to try this LEV Antenna.
Here are the parts I have ready to go:
I got the spring from Ace Hardware,
Century Spring C-253 9/16" diameter x 16-12" long x .054" spring wire diameter. It's a nice shiny stainless steel spring that deserves to be seen.
I got the clear PVC tubing from
http://www.clearpvcpipe.com
1/2" schedule 40 10 ft. length 1395-005
(10 foot minimum, fifteen bucks, more perfectly good beer money down the drain, wait til you see what the elbow and cap cost!)
1/2" 90 degree ELL (slip) $4.42
1/2" Cap (slip) $3.94
Two pretty brass 1/4-20 x 1-1/2" long and brass nuts at my local hardware store, a little long, I will need to cut them and chase them off with a die.
I ordered the AM ferrite core antenna and the trimmer capacitor and the alligator clip and extra coax antenna cable (RG-174/U) from:
http://www.oselectronics.com/
This site warns that they are behind on shipping up to 10 days after the order is placed, but they seem to have everything.
The clear PVC pipe has a slight blue tint, that gave me the BIG IDEA: to Illuminate the clear pvc pipe with Blue LEDs..... The Color of Electricical, as Eva Gabor would say in Green Acres! Ever seen a clear solid, glass or plastic, lit from the bottom with colored light? AHA, this proves I'm a genius.
Even better would be to have the led colors slowly fade in and out, blue with some red or pink fading in and out to make purple.
Even more betterer than that would be to tap the theremax circuit for pitch to control a low voltage LED 3 or 4 frequency color organ circuit so the plastic tubing will change color by pitch!!
That would be so cool, and it will satisfy those folks Les Paul refers to as people who hear with their eyes.... (there's gotta be something visual for some)
I'm gonna use plastic polish on the clear pvc pipe parts, you can find that in the car polish section anywhere, there are several brands, it's meant for cleaning up plastic headlight lenses, and it works great.
It might be March or April before I get this whole Lighted Lev Antenna happening, but it might be a lot quicker. I won't be mad if someone beats me to it, but I have a feeling I'm gonna be the "first kid on my continent" to have one!
Snuffy

Again, thanks for the help. Your plan for your theremin sounds pretty cool! I will definitely check out some of those sites you mentioned. As for the missing resistor, I'll just do what you did. (Buy one at R.S.)
Scorch77

DIODE INDENTIFICATION
The instructions say "three types of diodes are used in the Theremax... these parts will be separately packed... if they get mixed up you will have a hard time sorting them back into types"
Boy, that's for sure! The six teeny tiny diodes were loose in the bag with all the other parts in my kit. The body of these things is about 3mm long and 1mm diameter. I had to use a 30x pocket microscope to pick out the one that is different (D1) from the other five (D1-D14).
There acutally are tiny part numbers on them that do not relate at all to the type of diode listed in the manual. If they're mixed up you gotta go through them under a strong magnifier til you find the one that's different from the others.