Quote:
Originally Posted by jonboy55
Here is another radio I'm trying to identify.
Tube lineup is 43, 6C6, 6C6 (?), 25Z5, and ballast. By the way, there is no eye tube. What you think is the eye tube is painted on the dial. I also think the dial doesn't go with this radio. This dial has 2 bands, but the radio only has 1 band.
Any help would be greatly appreciated.
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The eye tube is
painted on the dial? That's interesting. If this radio is homebrew as at least one poster here has said, I would think whomever built the set could have wired a real 6E5/6U5/6T5 or other magic-eye tube into the signal circuits (AVC line) and mounted the tube in the same spot where the painted-on "eye tube" is now. The filament wiring could be a problem, however, as this radio seems to have a series-string filament arrangement with a 25Z5 and a ballast tube. It may or may not have enough reserve to power another tube. Depends entirely on the total filament voltage of the entire string; if it equals the power-line voltage, it could work. On the other hand, this may be why this radio has a ballast tube -- to take up whatever filament voltage is left after the four other tubes. I'm not familiar with tubes such as 43, 6C6, etc. (these were before my time), so I don't know what the filament voltage was. I would guess six volts, but that's just a stab-in-the-dark guess that may be way off. Since this radio has a ballast, however, I would guess the total filament voltage of the entire string must be well under the line voltage, with the ballast, of course, taking up the slack.
As I understand it, ballast tubes were the predecessors of resistance line cords and, later, wirewound filament dropping resistors. Ballast tubes were also used in early television power supplies, as I read in an old TV service book years ago; many a house fire was started when a ballast failed and the set owner carelessly jumpered across the defective tube. This may have gotten the TV or radio working again, but such a dodge can and often did result in serious damage to the unit or even the house wiring. Case in point: There was an incident back in the 1960s in Cincinnati, Ohio, where a homeowner, tired of replacing fuses when his wife's kitchen appliances kept blowing them, finally went down to the fuse box and placed a copper penny behind the defective fuse. This restored the electricity, all right, but it also removed the protection the fuse afforded the line, eventually overloading the house wiring and starting a costly fire behind the walls.
Today's electric service panels, with their bolted-in circuit breakers, are incorruptible, since there is no way a homeowner can bypass them; all he or she can do is flip the breaker back to its on position when it trips--after removing the short or overload, of course.
The AC power cord looks as if it is frayed at the point where it enters the chassis. I'd replace it before doing too much more with the radio. Also, it looks to me as if there may be a quartz crystal (possibly a small FT-243) in front of the antenna coil -- strange for a broadcast/SW radio of this vintage, but if it's a homebrew unit just about anything is possible. That component could even be a capacitor.
It's difficult to tell, even after enlarging the thumbnail.