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:
“I may be able to spot arrowheads on the desert but a refrigerator is a jungle in which I am easily lost. My wife, however, will unerringly point out that the cheese or the leftover roast is hiding right in front of my eyes. Hundreds of such experiences convince me that men and women often inhabit quite different visual worlds. These are differences which cannot be attributed to variations in visual acuity. Man and women simply have learned to use their eyes in very different ways.”
—Edward T. Hall (b. 1914)
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—Joseph Featherstone (20th century)