Make
ABC Electronics
Model
250 Plus
Overview
The ABC Electronics 250 Plus is a vintage tube-type linear amplifier designed for 11-meter CB and 10-meter amateur radio operation. Produced during the CB radio boom of the 1970s, it is a base-station amplifier using multiple sweep tubes to achieve higher RF output levels. The model is also associated with the Contex 7210 designation in some documentation sources.
Technical Specifications
| Specification | Details |
|---|---|
| Manufacturer | ABC Electronics |
| Model | 250 Plus |
| Type | Tube linear amplifier |
| Service | CB / 10-meter amateur use |
| Configuration | Base station |
| Tube Complement | 3 × 6JG6A sweep tubes plus driver tube (reported) |
| Power Source | 120 VAC |
| Cooling | Internal fan |
| Construction | Point-to-point wired chassis |
| Documentation | Schematic and parts list available |
Physical Description
The 250 Plus features a metal cabinet with a horizontal base-station form factor. The front panel includes controls for tuning and loading, along with a power switch and metering functions depending on the version. Ventilation openings are located on the top and rear panels, with a rear-mounted cooling fan to dissipate heat from the tube section. Internally, the amplifier uses a steel chassis with large transformers and hand-wired circuitry typical of the era.
History
ABC Electronics was one of several manufacturers producing tube-type linear amplifiers during the 1970s CB radio expansion. The 250 Plus became a commonly encountered multi-tube base amplifier among operators seeking increased transmission power. Surviving units are often restored by collectors and hobbyists, with documentation preserved through online archives and enthusiast communities.