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Salvaging components from a TV receiver.
No ham shack is complete without the proverbial spare-parts junk box. Here's a good way to start one. The author estimates a $71 return in usable components for a $5 investment.
How many times have you run across articles reading somewhat as follows: "If you have a well-stocked junk box, this equipment will cost almost nothing," or, "The power transformer from an old TV set is ideal for the power supply."? Almost as often, the sentence that proves fatal to so many construction projects appears. Usually it goes something like this, "Total cost, if you purchase all parts new, will be approximately $50.00."
If you have an overstocked junk box, a bank account in the same condition, or never intend to build a piece of electronic equipment, stop reading; this article isn't for you. However, if you can't qualify for membership in this select group, get set to strip components from an old TV set and join the ranks of the Electronic-Parts Plutocrats.
The photograph offers ample evidence that there is a very large number of valuable parts awaiting the enterprising ham in almost every old television set. Of course it isn't necessary to straighten the leads so nicely, and seldom will a junk box boast so many clean and bright components, but the appearance of most parts colections will be benefited by the little extra work required.
The approach
How do you become a TV-set stripper? The prescribed formula is as follows: Take your telephone directory and turn to the yellow pages. Under "Television" the names of local TV repair shops and merchants will provide a list of potential sources of "so-called" junk sets. Jot down the numbers and dial one selected at random. Briefly explain your reason for calling. Include the fact that you are an amateur radio operator if you are licensed. Usually you will get a quick, " Yes, we have some old sets," or "Sorry, we just threw out all our old junk." At any rate, chances are sooner or later one of the names on the list will come through with the answer your ears have been straining to hear. " Yes, we have loads of old junk TV sets."
Once you get this answer, take a few dollars, a buddy to help load the plunder, and dash down to scout the lay of the land. At this point the old charm should be exercised in its most eloquent form. This may sound a little on the shady side, but it is just using good common sense. You can't afford to pay much for the old set, and yet the shop owner must get what h considers a fair price for his merchandise. You aren't buying a "fair-trade item," and he wt charge in accordance with what he thinks the set is worth. Here again the old rule which dominates all other price structures comes into play - the rule of supply and demand. If no one comes around looking for old sets, they are useless and worthless. If demand for old sets arises, their value goes up. An over-eager or anxious purchaser can create that demand. It is reasonable to assume that unless a certain amount of restraint is exercised in trading, you may come away empty handed and leave a disappointed businessman who has wasted valuable time because no sale was made. The price, naturally, will depend to a great extent on the condition of the set and components left intact. Remember to look for the power transformer and check its condition. Take a close look at the wiring and smell the transformer leads. A burned-out transformer usually gives off a strong odor of burned varnish or lacquer.
Removing components
When you hoist the prize onto your workbench and begin removing parts, the fact that a TV set attracts large amounts of dirt and grease will become apparent. Parts will often be completely. encased in a substance having the appearance of soot. An outstanding characteristic of this coating is the tenacious way in which it resists removal. A soft cloth moistened with mineral spirits, and a little elbow grease, will provide the solution to this problem. Parts soon emerge bright and glistening, actually preserved by the grime.
Exercise good workmanship in removing parts from the set. As in every other worthwhile project, a little extra care and patience pays large dividends here. Resistors and capacitors hurriedly cut loose or jerked out of the set will often prove very difficult or impossible to use. A hot soldering iron with a clean tip and adequate capacity is a big help. It will enable you to melt soldered joints quickly so that parts can be removed before they are heated excessively. Grasping leads with needle-nose pliers also helps reduce danger from overheating. Above all, work carefully. High-quality parts will emerge from the TV set only if they are treated as such.
This neat collection of parts was lifted from a single discarded TV chassis. (Photo by Bob Lancaster.)
Your Profit?
Are the salvageable parts worth the time and effort and the price of the set? Obviously the answer is a definite yes. In a typical case, a hasty check on those components likely to be useful to the home builder revealed that the initial cost of five dollars (the cost of the set from which the pictured parts were taken) amounted to less than one-fourteenth their catalog value. Absolutely no effort was made to obtain a "special" set, and parts shown were all removed from one chassis.
Naturally, all the material taken from an old TV set will seldom be used by anyone. However, a few parts can be put to use in almost any project, and articles boasting that the equipment described can be built for nothing if the builder has a well-stocked junk box will take on new meaning for you.
Identifying values
Only after all parts are disassembled and neatly arranged in cigar boxes, plastic boxes, or perhaps an old chest of drawers, will the real challenge face a large number of amateurs. This is the problem of learning to identify parts and determine component values from color codes. The Radio Amateur's Handbook is a fine place to obtain knowledge of this sort. The chapter entitled "Construction Practices" contains a wealth of information on the color coding of resistors, and ceramic and mica capacitors. It also covers the color coding of power transformers, i.f. transformers, a.f. transformers loudspeaker coils, and loudspeaker field coils.Manuals included in kits of electronic equipment such as the Heathkits also contain very good information on color codes. The little resistor and capacitor calculators sold for twenty-five cents each are often an excellent investment. These handy little gadgets will quickly give the user the value of many color-coded components.
Catalog prices of items in the photograph are shown below. Items such as the flyback transformer, yoke, hardware, etc., are not included in the list.
| Catalog Price ($) | Item |
|---|---|
| 9.85 | Resistors |
| 3.28 | Sockets, plugs, jacks, line cord, etc. |
| 22.00 | Tubes |
| 2.33 | Tie strips, insulators, shields, etc. |
| 11.00 | Power transformer |
| 2.75 | Choke |
| 2.00 | Output transformer |
| 8.51 | Electrolytic capacitors |
| 9.28 | Ceramic, mica, plastic, and paper tubular capacitors |
| 71.00 | Total catalog value |
| 5.00 | Total cost |
| 66.00 | Indicated savings |
There are, of course, other ways to learn the value or function of strange components you will find in your set. Almost any TV repairman, or ham who has been around for a long time, or clerk in an electronic-parts supply house will usually be glad to give valuable information about the various parts that have strange color codes or are exotic in appearance.
Picture-Tube Disposal
One word of caution - most old sets will have an equally old picture tube. Extreme caution should be used in handling and disposing of this dangerous piece of glass. If available, a face mask or safety goggles should be worn when handling the tube. After all connections and fastenings are removed, the tube can be slid gently from the chassis. If possible, place it in a cardboard box immediately. The box will provide protection and, in the event of accidental breakage, will reduce the velocity of flying glass so that it is less lethal. A phone call to the local parts distributor, or one of your city or county officials, will usually provide information on how and where to dispose of the tube.
OK, Plutocrat, you have your junk box.
Bill Haywood, K4ATG.