radio and communications

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    125kHz RFID Reader and Huge Field Antenna

    Hello everyone Link I'm working this circuit for a weeks. But i can't seem to understand full details and it's working since i'm almost newbie to Radio Communications. So i have few questions on this circuit. 1.Can anyone explain me deeply about this circuit? 2.Is it possible to change antenna...
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    Remotely open door by using same Intercom switch using remote Switch

    Hi, I don't have much knowledge about electronics but I have bought a remote switch using which one can remotely (100 meter distance) turn on/off a light or any other appliance. There is a two buttons "bpt" intercom in my unit. I want to use this remote switch with that intercom such that...
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    Object Identification Help: Likely part of an old Military Radio

    Hello everyone. Hopefully this is the right place to post this, I've been asking all over the internet for help identifying this object I have pictures of and this place seems like an active place to ask. I'm not the first person to try identifying this, but I do believe I've been the most...
  4. How to make an Oscillator for AM radio transmitter?

    I was looking for an 1MHz oscillator for AM radio transmitter circuit. But I couldn't find one with the 4 pin crystal quartz oscillator. How to make an oscillator by myself with basic electronics materials? Any Circuit or ideas?
  5. question about an AM demodulator IC ?

    hello guys i found in my electronics salvage an old ic its a TDA3845 when i searched for it and looked at the datasheet i saw that its a Quasi split-sound circuit and AM demodulator . so my question is : 1- what is Quasi split mean ?? 2- i was wondering can i use it to make an AM or FM radio...
  6. Can RF transistor junction be used as a diode?

    It it possible to use some ancient vintage NPN germanium transistors' base/emitter as a 2-lead germanium diode? What about the higher-frequency BFY90? I have been given a "scrap" box full of old OC76 and (OC90?). Simply for experimentation in RF filters & tanks.
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