![]() are you getting lots of hash and noise but nothing intelligible? is the radio right next to a computer or lithium battery charger? those two things can generate plenty of RF noise on an AM radio. the actual production model just re-used the tube sockets. on a humorous note, the pictorial diagram shows the transistors in transistor sockets. your radio should have a pictorial diagram inside like the one in pic 3. it's possible your radio may play loud, in that case back down on the volume control. apply power, turn the radio on at full volume, and tune around. ![]() on the connector at the end of the cable, the terminal at the very end (not where the wires come in to the connector) is the positive terminal. look at the old battery connectors coming out of the radio. you can use a regulated power supply or a 9v battery and alligator clips. you risk damaging some VERY hard to find transistors. now is a good time to see if your radio works at all. ![]() it has two battery connectors but both are wired in parallel. it's easy to open so you can replace the batteries. the hinge is at the bottom and the radio splits open right along the center inline with the knobs. This radio is housed in a hinged split case. ok, enough history, let's see whats inside. in a radio like this, batteries of that size would easily last over a year with daily use. power was furnished by (2) 9V brick style batteries. the big ferrite antenna helps it pull in stations much better than the 4 transistor sylvania reflex radio i have in a different instructable. using only 4 transistors in a circuit that used to be setup for 4 tubes, this early transistor radio performs quite well despite it's low transistor count. what to do? you take one of your current vacuum tube radios, have your engineers redesign the circuit, and shove the transistor leads right down the same sockets the tubes used to plug into! that's what the 1956 olympic 447 is all about. you're anxious to get on the transistor radio bandwagon but don't have the R&D budget that the big boys have. let's say your a radio manufacturer in the 1950's but not one of the big boys. when it comes to first generation transistor radios, the olympic 447 is in a league all it's own. eventually the big lunchbox sized AM only radios fell out of favor and were replaced by shirt pocket AM radios that weren't much bigger than our current cellphones. portable radios were not a new idea but transistor technology meant your batteries could now last a year or so instead of a few hours like they did with tube portables. these big transistor radios where called "lunchbox radios" and were how folks took their entertainment outdoors 50+ years ago. **this instructable assumes that you have basic electronics knowledge, you can solder, and you have the ability to use basic hand tools.** in this instructable we'll be covering the basic rebuild of an early portable transistor radio.
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