Breathing New Life Into a 1950s AM/FM Radio

There are many large electronics vintage looking out there that unfortunately no longer function. Restore the original circuit can be laborious and still leave you with a device that relies on outdated components. Here we take a great looking AM / FM radio from the 1950s and replace its innards with a modern transistor radio.

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We start by choosing a conventional AM / FM radio. You can find these vintage stores, garage sales, or in the family attic.Because we are not to determine whether the circuit works, you can choose based on radio appearance. Make sure the radio you choose has all its buttons, all the President of fabric covers are in good condition, and the button moves frequency radio station (frequency) of the indicators.

We start by removing the back of the radio, and how the controls work.You can put aside all tubes and components in bulk (and you probably will not need them later). Buttons are often attached to the front plate, and attached to components with metal strips. You will need to remove the metal strips before sending the buttons from the front of the radio.

With vintage radios, the chamber is a room really separate from the electronics inside, so you should be able to completely eliminate the electronics housing made of wood. Here is a picture with the electronics sit on top of the radio housing. The buttons were removed and discarded during disassembly.Note the system of pulleys and ropes that moves the frequency indicator. Interfacing with this will be a fun challenge.

We now have a better idea of ​​how the controls operate radio. The tuner is a mechanical assembly, as opposed to an electronic button. Selecting AM / FM is controlled by a slide switch. Power and volume are controlled by a single button clicks on / off and then turns again to control the volume. Finally, there is a button to "tone" that we will not use.

Now it's time to open the pocket radio and see how we can interface with the controls.The bag is opened by removing the visible screws (be sure to check uUnder the battery door, and / or sub stickers.) After the screws are removed, all that holds the two halves of the radio tabs and plastic hook.

Rough Record: 555 timer ic tutorial

N this tutorial I will show you what exactly the 555 timer is and how to properly use it by itself or in combination with other solid state devices without the requirement of an engineering degree. This timer uses a maze of transistors, diodes and resistors and for this complex reason I will use a more simplified (but accurate) block diagram to explain the internal organizations of the 555. So, lets start slowly and build it up from there. The first type-number, in Table 1 on the left, represents the type which was/is preferred for military applications which have somewhat improved electrical and thermal characteristics over their commercial counterparts, but also a bit more expensive, and usually metal-can or ceramic casing. This is analogous to the 5400/7400 series convention for TTL integrated circuits. he 555, in fig. 1 and fig. 2 above, come in two packages, either the round metal-can called the 'T' package or the more familiar 8-pin DIP 'V' package. About 20-years ago the metal-can type was pretty much the standard (SE/NE types). The 556 timer is a dual 555 version and comes in a 14-pin DIP package, the 558 is a quad version with four 555's also in a 14 pin DIP case. I nside the 555 timer, at fig. 3, are the equivalent of over 20 transistors, 15 resistors, and 2 diodes, depending of the manufacturer. The equivalent circuit, in block diagram, providing the functions of control, triggering, level sensing or comparison, discharge, and power output. Some of the more attractive features of the 555 timer are: Supply voltage between 4.5 and 18 volt, supply current 3 to 6 mA, and a Rise/Fall time of 100 nSec. It can also withstand quite a bit of abuse. he supply current, when the output is 'high', is typically 1 milli-amp (mA) or less. The initial monostable timing accuracy is typically within 1% of its calculated value, and exhibits negligible (0.1%/V) drift with supply voltage. Thus long-term supply variations can be ignored, and the temperature variation is only 50ppm/°C (0.005%/°C). ll IC timers rely upon an external capacitor to determine the off-on time intervals of the output pulses. As you recall from your study of basic electronics, it takes a finite period of time for a capacitor (C) to charge or discharge through a resistor (R). Those times are clearly defined and can be calculated given the values of resistance and capacitance. he basic RC charging circuit is shown in fig. 4.