Variations On The Theme
Although four-, six-, and even a few rare eight-tube radios were produced, they were not common. The four-tube version with vacuum tube rectifier was of inferior performance, as they typically had no IF amplifier tube, although some four-tube designs with a selenium rectifier in place of the rectifier tube avoided this problem. The six-tube versions added either a RF amplifier tube, a push-pull audio power amplifier tube, or a beat frequency oscillator tube (to listen to Morse code or single-sideband modulation transmissions). However, these radios cost significantly more and sold in smaller quantities. The eight-tube versions cost even more, adding two or more of the features of the six-tube versions and sometimes an extra IF amplifier tube.
| # Tubes | RF Amp | BFO | Converter | IF Amp | Det/Pre-amp | Audio Amp | Rectifier |
|---|---|---|---|---|---|---|---|
| 4 | X | X | X | X | |||
| 4 | X | X | X | X | (selenium) | ||
| 5 (standard) | X | X | X | X | X | ||
| 6 | X | X | X | X | X | X | |
| 6 | X | X | X | X X (push-pull) | X | ||
| 6 | X | X | X | X | X | X | |
| 8 | X | X | X | X X (push-pull) | X X (push-pull) | X | |
| 8 | X | X | X X | X | X X (push-pull) | X | |
| 8 | X | X | X | X X (push-pull) | X X (push-pull) | X | |
| 8 | X | X | X | X | X | X X (push-pull) | X |
Read more about this topic: All American Five
Famous quotes containing the words variations and/or theme:
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