The component numbering system is from our modernized schematic/Art Harrison's RCA Theremin write up. Component values are taken from the original RCA Theremin Service Notes, the RCA Theremin Replacement Parts document, Art Harrison's write up, or measured from original RCA Theremins directly.
|
Value |
Location |
Description |
Value Source |
| T1 |
|
SPU |
Power Transformer |
| T2 |
~55 µH |
chassis |
volume oscillator coil (inner winding) |
Measured from theremin |
|
~60 µH |
chassis |
volume oscillator coil (outer winding) |
Measured from theremin |
| T3 |
~12 mH |
10" coil form |
volume control resonant coil |
Measured from theremin |
|
~15 µH |
10" coil form |
volume control pickup coil |
Measured from theremin |
| T4 |
~1k Ω |
chassis |
A.F. Transformer, GW-42 (primary) |
Measured from theremin |
|
~5k Ω |
chassis |
A.F. Transformer, GW-42 (secondary) |
Measured from theremin |
| T5 |
|
speaker |
RCA 106 Loudspeaker output transformer |
| T6 |
~175 µH |
chassis |
pitch reference oscillator coil (inner winding) |
Measured from theremin |
|
~195 µH |
chassis |
pitch reference oscillator coil (outer winding) |
Measured from theremin |
| T7 |
~1k Ω |
chassis |
A.F. Transformer, GW-42 (primary) |
Measured from theremin |
|
~5k Ω |
chassis |
A.F. Transformer, GW-42 (secondary) |
Measured from theremin |
| T8 |
~175 µH |
chassis |
variable oscillator coil (inner winding) |
Measured from theremin |
|
~195 µH |
chassis |
variable oscillator coil (outer winding) |
Measured from theremin |
| T9 |
~30 mH |
12" coil form |
Pitch control resonant coil |
Measured from theremin |
|
~20 mH |
under 12" coil |
Pitch concentrated coil |
Measured from theremin |
|
Value |
Wattage |
Location |
Type |
Value Source |
| R1 |
2,250 Ω |
|
SPU |
wire wound plate |
Service Notes |
| R2 |
14.3K Ω |
1 W |
SPU |
dogbone resistor |
Service Notes |
| R3 |
20K Ω |
3 W |
SPU |
dogbone resistor |
Service Notes |
| R4 |
30 Ω (~14 Ω) |
|
SPU |
center-tapped wire wound |
Replacement Parts (Measured) |
| R5 |
30 Ω (~14 Ω) |
|
SPU |
center-tapped wire wound |
Replacement Parts (Measured) |
| R6 |
550 Ω |
|
chassis, multigang position 4 |
multigang wire wound |
Service Notes |
| R7 |
30 Ω (~14 Ω) |
|
SPU |
center-tapped wire wound |
Replacement Parts (Measured) |
| R8 |
30 Ω (~14 Ω) |
|
SPU |
center-tapped wire wound |
Replacement Parts (Measured) |
| R9 |
1000 Ω |
|
chassis, multigang position 1 |
multigang wire wound |
Service Notes |
| R10 |
625 Ω |
|
chassis, multigang position 2 |
multigang wire wound |
Service Notes |
| R11 |
420 Ω |
|
chassis, multigang position 3 |
multigang wire wound |
Service Notes |
| R12 |
100K Ω |
1 W |
chassis, under multigang resistor |
dogbone resistor |
Service Notes |
| R13 |
250K Ω |
1 W |
chassis, between G(V7) & GND |
dogbone resistor |
Service Notes |
| R14 |
10K Ω |
|
chassis, multigang position 5 |
multigang wire wound |
Service Notes |
| R15 |
5K Ω |
1 W |
chassis, between C7 and C17/C21 |
dogbone resistor |
Service Notes |
| R16 |
10K Ω |
1 W |
chassis, between SG(V2) & G(V1) |
dogbone resistor |
Service Notes |
| R17 |
5K Ω |
1 W |
chassis, between C15 and C17/C21 |
dogbone resistor |
Service Notes |
