Overview
The EICO Model 221 is a vacuum tube volt-ohm meter (VTVM) manufactured in 1952, representing classic analog test equipment favored by electronics technicians and radio amateurs. This vintage meter provides reliable AC voltage, DC voltage, and resistance measurements across multiple ranges. The EICO Model 221 became a staple in electronics workshops, amateur radio stations, and service benches during the post-war era.
Key Features
- Analog meter movement with multi-range scales for voltage and resistance measurements
- AC and DC voltage measurement capability across separate input terminals
- Ohms measurement with adjustable calibration control
- Vacuum tube circuitry delivering stable operation and good accuracy for vintage equipment
- Battery-powered ohms function using standard 1.5V flashlight cell
- Compact, durable construction suitable for bench and portable use
Technical Specifications
| Model | EICO 221 |
| Type | Electronic Volt-Ohm Meter (VTVM) |
| Manufacturer | EICO Electronics |
| Year Manufactured | 1952 |
| Measurement Functions | AC Volts, DC Volts, Ohms |
| Battery Type | 1.5V flashlight cell (user-replaceable) |
| Meter Movement | 0–1 mA DC full scale analog |
| Input Terminals | DC/Ohms, AC/Ohms, Common (ground reference) |
| Power Connection | 2-prong AC line cord (non-polarized) |
| Category | Vintage Electronics Test Equipment |
Typical Applications
- Electronics restoration and vintage equipment repair
- Radio and amplifier troubleshooting and alignment
- Laboratory resistance and voltage measurement
- Hobbyist electronics projects and circuit testing
- Collector’s display and educational reference
- Ham radio station measurement and calibration
Compatibility & Replacements
Compatible With
- Standard AC mains power supply (120V 50/60 Hz)
- Any circuit requiring DC/AC voltage or resistance measurement with standard test leads
- EICO PRF-25 probe accessory (optional, for high-voltage measurements)
Replaces / Drop-In Replacement For
The EICO Model 221 is a legacy vintage instrument. While direct modern equivalents exist, no current production units directly replace this model. Collectors and restorers seeking an identical replacement should search for other original EICO 221 units on the secondary market. Modern digital multimeters offer similar measurement functions but lack the vintage tube circuitry and aesthetic value of the original.
Works With
- Standard test lead sets with banana plugs and alligator clips
- External AC line voltage source for calibration reference
- 1.5V replacement batteries (AA or flashlight equivalent)
- Vintage tube-based radio and audio equipment servicing
