If you are shipping or receiving an RCA Theremin, here are a few tips to minimize the risk and ensure a smooth delivery. In all cases, you are dealing with a rare and valuable artifact. Treat it as such.
You will want to separate out the theremin components into 4 main groups:
First, before anything else, disconnect the AC plug from the mains or house current to prevent electric shock. Then, remove the volume loop and pitch rod antenna from the cabinet and set aside. Next, carefully remove all vacuum tubes from the upper chassis and the SPU: Grasp the vacuum tubes by their black Bakelite bases, not the glass, and gently tug upwards, gently rocking back and forth very slightly as you pull the vacuum tube out of its socket. Wrap each individual vacuum tube and package separately.
The upper chassis sits on a wooden tray that slides in and out of the cabinet. The wiring harness, a long bundle of cables hardwired to the upper chassis, connects to the SPU (The
Socket Power Unit power supply) on the cabinet floor via U-shaped terminal lugs. With a short, flat-blade screwdriver, remove the L-shaped brown metal terminal shield (if it still remains), that covers the strip of screws on the SPU. Then loosen, with a few turns each, the screws that hold down the terminal lugs for each wire (don't worry, the screws won't come out from the strip). Avoid excessive force to avoid possible fracture of the phenolic terminal-mounting strip. Carefully withdraw each of the 9 colored wires from its screw terminal, pulling back only far enough to clear the terminal strip. It can help to loosen all of the screws at the same time (backing out about three turns each), and then withdrawing the row of wires more or less together. It will aid re-installation if you can maintain the order of these connecting wires. A splint made from a pair of stiff cardboard strips, each measuring one by six inches, secured snugly with tape can help. Avoid getting tape or adhesive on the wires themselves. Handle the wire minimally to avoid putting kinks and breaks in the fragile insulation!
The splint will prevent the wires from migrating during transit. If any of wire ends trade places during packing or subsequent reinstallation, consequent damage to the instrument can occur. The other important task of the splint is to keep the spade lugs stabilized at the end of each wire. When fabric-insulated wire ages, two things can happen: It can dry rot, making it soft and limp (can look fine until you start handling it and then it crumbles), or temperature extremes during long years of storage can make the insulation hard & brittle. If the wires have already been connected and disconnected from the terminal strip a number of times, individual wire strands can break loose at the lugs, putting the remaining strands at greater risk if the lugs and/or wires are allowed to move about too much. Therefore, please handle the wires with care and secure them thoughtfully.
Follow the bundle of cables with your eye and make sure that there are no retainer clips holding them down to another part of the cabinet. If there are, loosen the retaining screw on the clip, release the cable, and tighten the retainer clips back down.
Next, remove the cables that connect the large coil forms to the brass antenna mounts. Carefully unscrew the small nut from the top of the coil and remove the circle lug that connects to the wire to the top of the coil (many RCAs have had their circle lug modified so they act as spade lugs for easier removal) return the nut to the bolt and tighten by hand. Do this for both coils, leaving the wires to dangle. When you remove the chassis board, make sure the dangling wires do not get caught in the fine wire that surrounds the large coils. If the nut is tight, do not force it loose, as you may damage the coil form or the delicate wire connected to the inside of the terminal. In this case, loosen the large nut on the antenna mount to remove the wire instead.
Next, find the 2 screws (if present) that secure the chassis to the cabinet. If the theremin is a GE theremin (see identification), these screws will be pocketed in the corners of the chassis board. If the theremin is a Westinghouse, they will be on the top of the chassis board at the corners. Remove these screws, bag and label them.
Next, carefully slide the chassis board out about 5 or 6, inches being careful not to let it tip/fall out. Find the Play/Off toggle switch on the front of the theremin (the upper one) and remove the knurled washer and Play/Off escutcheon if present. From the inside of the cabinet, with one hand holding the switch, and with the other hand from the outside of the cabinet, push the switch through the hole into the cabinet. The cable that holds the Play/Off switch might be attached to a retainer clip as well, so follow the same procedure. Reinstall the escutcheon and knurled washer onto the switch and wrap with bubble wrap or tissue. In some cases, especially if the switch has never been removed, the nut can be somewhat stuck to the switch. To avoid scarring or scratching the hardware and cabinet finish, always use padded pliers (small) if necessary, and avoid contact between the tool and the cabinet. You may find it helps to loosen the nut by slightly rocking the body of the switch from the inside, while you hold the nut steady from the outside.
Now, with the cabinet doors fully opened, carefully slide the chassis board out fully and place on a soft surface, being mindful of the fragile wiring harness which passes through the hole in the chassis board.
The SPU is attached to the bottom of the cabinet with 4 long machine screws with slotted oval heads. Each screw should have a washer, a lock washer and a nut, although these can be missing. Remove and place the hardware in a zip locking bag or film canister and label.
There is a two-wire AC power cable that connects the SPU to an auxiliary black Bakelite AC socket that is screwed down to the cabinet floor. Using a small slotted screw driver, remove the top of the receptacle and then loosen the screws that hold the brown cable that goes to the SPU. Do not disconnect the wires on the lower toggle switch (On/Off), as this can remain attached to the AC socket and safety interlock switches.
The SPU can now be removed after the chassis board has been removed as well.
The large coils are held to the board by 3 long machine screws each, with washers, lock washers and nuts. Prepare a long sheet of paper and very carefully wrap this around each coil, so that each sheet forms a snug sleeve, covering all of the delicate wire windings. Secure the paper tightly to itself (not to the coils or coil forms) to keep it from sliding off and damaging the windings. Carefully tip the chassis board on its side, avoiding stress to the wiring harness. Remove the coil mounting hardware from one coil at a time, and then remove the coil from the panel. Take care to avoid any contact between the delicate coil wire windings and the rear edge of the metal chassis, as clearances are close. Place the hardware in a zip locking bag or film canister and label accordingly.
There is a small coil (concentrating coil) mounted on a bracket in the base of the tall pitch coil (the one with the longer wire area). Due to shrinkage of the wooden core at the center of this small coil, and hardening of the sealing wax, this coil can come loose from its wood core, shearing the hair-fine connecting wires. To avoid this damage, pay attention when you first remove the tall coil from the shelf, and secure the concentrating coil by gently placing soft tissue over it, sufficiently thick to pad and support the concentrating coil within the bottom of the tall coil form. Wrap a soft cloth or yielding paper around the bottom of the entire coil form, overlapping the paper sleeve, and carefully secure with two rubber bands (in case one breaks in transit).
Now that the internals are removed from the cabinet, the cabinet itself is much lighter and easier to transport. It's very likely that the legs of the theremin, if they have not been removed or repaired, will be very loose though still fully connected. Be careful at this stage, and at all times when moving the RCA Theremin, to lift the instrument from the cabinet floor and mind the legs when transporting.
If you have not removed the On/Off switch, do that now in the same way as the Play/Off switch and wrap and leave inside the cabinet, connected to the auxiliary black Bakelite AC socket and safety interlock switches. This helps prevent damage to the switch when transporting the cabinet.
This may sound obvious, but it's an important step. If you are shipping parcels which have heavy or fragile items in them, you should box the items with ample amounts of padding/foam/packing peanuts in the box, but then place that box in a larger box with more padding/foam/packing peanuts. This decreases the chances that the inner box will be crushed, damaged, or punctured. If not crating with wood, be sure to use only strong, fresh cartons to reduce the chance of damage to the cabinet, breakage to the legs, etc. It's also a good idea to place a thin pad between the music shelf and the cabinet slanted panel to avoid impact or abrasion damage at that location. Do not secure the doors with tape or use adhesive of any kind on the cabinet itself. Soft cord may be used as needed to secure the doors and music shelf.
We have designed a sturdy packing crate for the theremin cabinet using dimensional lumber, foam, and half-inch plywood. The plans are avialble for sale on our Parts page.