Externally, the chassis looks identical to the 22BD. Exception: the 22BD has the jack for the speaker connection - two female sockets - on the right (antenna) side of the chassis; the 3BTD has a 3` harness (Black and Green wires) exiting the left side (same side as the power leads) and is a combined male/female connector.
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Refer to the pics I have of the earlier 22BT model. A good location to find the AM signal, is the connection shown below (if the RF/Converter/IF stages are OK). You`ll only get a waveform if you`ve tuned in a station, so watch the `scope while tuning. . . I pulled the first two transistors in the amplifier stage (Q4 & Q5) and they looked good and checked OK, checked a few resistor values, all looked OK, soldered everything `em back in and lo! All of a sudden, it plays. I *hate* that. "Early solid state car radios used all germanium transistors. The most common failures were the RF amp, Local oscillator, and the converter (Mixer) transistors. The easiest way to find the bad transistor is to check the collector votages. If you find one that`s near zero, the transistor is open. I used to test, find the bad part and repair the radio in less time than the service clerk took to write up the work order, and all I used was a meter, signal tracer, and an old signal generator. Over 95% of the failures were open transistors, and the replacement parts weren`t critical Something rated for RF in the low ECG numbers worked very well. " Well, open transistors are not terribly common on the monitors I`ve repaired (different tech, different era, no germanium stuff), so I am grateful for this advice from someone who`s been there. After two days` running on the bench, the radio is still running fine, but I think I`ll just replace all the...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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