Denver craigslist

[Jeffhs]

Originally Posted by jr_tech

Emerson 571/606...look at all of those 25Z6 rectifiers! Is the fireplace fake?

jr

I would think it is in fact fake. Since the television is mounted directly above the fireplace, the intense heat, not to mention smoke and soot, would damage the set in a very short time. I know someone who has her TV (a 32" flat screen) next to her fireplace in her living room; however, the set is not built into the wall, but is on a TV stand, positioned far enough away from the fireplace not to be in any danger of being damaged.

However, as I said, a built-in set, with the TV directly above the fireplace, such as the one being discussed here, could be severely damaged the first time said fireplace was used. The only exception would be if the fireplace is a modern one that uses multicolored bulbs or LCD panels to create simulated flames; I think that may well be the scheme used with this one. The TV, of course, cannot be harmed unless one or more of the bulbs (no danger, of course, if an LCD panel creates the image) are physically close to the bottom of the set's cabinet, which I seriously doubt since the bulbs would almost certainly be located in what would be the fire pit of a wood-burning fireplace, well away from the TV itself.

The 25Z6 rectifier tubes' filaments could be wired in a series-string arrangement, so as to operate directly from the AC line without the need for large dropping resistors; 25x4=100, with the resistor(s) being used to take up the slack. When this set was new, most areas had 117-volt AC line voltage. Today, many areas have line voltage measuring somewhat more than 120, which would of course require even larger or more dropping resistors in the TV to prevent damage to the tubes. However, why this TV uses four of these tubes is beyond me; most '50s-'60s TVs that did not have selenium rectifiers were designed with one or, at most, two low-voltage rectifier tubes. The CRT is not that large (I would guess it is no more than perhaps nineteen inches), so the power supply does not need to be a big 400-watt bruiser unless the set was originally part of a 3-way entertainment center, which I doubt. The only other thing I can come up with is one or two of those tubes are used in the HV power supply, although one would ordinarily expect to find one or, at most, two 1X2s or 1B3s in this position.