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TRF
RADIOS
Part 6 Andrei Lazarescu's Projects |
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ANDREI LAZARESCU'S RADIO PROJECTS . |
MK484 T.R.F. Radio My name is Andrei, I was born in Romania in 1987 and one of my hobbies is electronics. In the following lines I will present to you a simple MW radio. The radio consists of two sections: R.F. and A.F. I combined the R.F. section with adjustable selectivity from this reference: http://www.zen22142.zen.co.uk/Circuits/rf/ZN414.htm and also from here: http://braincambre500.freeservers.com/MK484%20Receiver.htm The A.F. section is from here: http://www.radiomuseum.org/forum/mk484_und_detektor_empfaenger_basteln_mit_mk484.html and here: http://radiosammlung.homepage.t-online.de/seite8.html The result? A performance receiver, sensitive (and selective, if it is adjusted or at night), with a high quality of sound. I used a small Medium Wave antenna from a walkman with digital radio and a variable capacitor (VC) with two sections connected in parallel from an old russian radio (2x280pF). I read on the Internet that if you live in an area with strong signals and you want to achive good performance and quality with this 3 pin IC (MK484,ZN414 etc) you have to: A) use a small or smaller ferrite rod; B) use a variable supply to adjust the IC voltage (0-1,4V); C) use two coils for the ferrite rod: main coil - L1 (for tunning) and second coil - L2 (inductive). You can try A, B or C, each of them improving the performance of the receiver. But, if you use all of them (A+B+C) your receiver will work very well! The HP Jack allows you to connect a headphones and switch between internal speaker and headphones. The DC 9V Jack allows you to connect an external power supply of 9V to the receiver and switch between internal 9Vbattery and external power supply. In the left side of diagram are equivalents (found by me from different webpages and noticed all on a notebook) of the RF circuit. In the right side of diagram I present a good, simple stabilised source for 9V. Here is an audio clip recorded from the completed radio: Click to Listen to the Audio Andrei.  Schematic Circuit Diagram of Andrei Lazarescu's MK484 TRF Radio Project      Photographs of Andrei Lazarescu's completed MK484 TRF Radio  Andrei Lazarescu Audio Amplifer Here is another project of mine. It is a small amplifier of about 5W max. It can be feed by an iPod,small radio, tape or sound card from pc with good results. The diagram is simple and the amplifier has only two knobs - power and volume."Modul A" is the original power supply, "Modul A' " is the modified power supply and "Modul B"is the power amplifier with TDA2003. Andrei.  Andrei Lazarescu's Audio Amplifier Circuit Diagram  |
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To More Electronic Projects Visit the EVERYDAY AND PRACTICAL ELECTRONICS Website |
No
AM radio stations or transmitters in your locality or country?
 Has your
local medium wave broadcast station closed or been moved to VHF/FM or
Digital? Don't worry. You can
still build and experiment with crystal sets and TRF radios by
also buying
or even building a simple low power AM transmitter. So, not only can
you use your
crystal sets but you can also run your own radio
station that can be heard in and around your home - playing the music
or programmes that you want to hear!
SSTRAN
AMT3000
Superb high fidelity medium wave AM transmitter kits from SSTRAN.
Versions available for 10kHz spacing in the Americas (AMT3000 or
AMT3000-SM) and 9kHz spacing in Europe and other areas (AMT3000-9 and
AMT3000-9SM). Superb audio quality and a great and well
designed little
kit to build: http://www.sstran.com/pages/products.html
 http://www.sstran.com/ Other AM transmitters available:
Spitfire
& Metzo Complete, high quality ready built medium wave AM
Transmitters from Vintage Components:
http://www.vcomp.co.uk/index.htm Vintage Components offer a choice of the high quality Spitfire and Metzo transmitters: SPITFIRE AM Medium Wave
Transmitter with 100 milliwatt RF output power:
 METZO AM Medium Wave Transmitter with built in compressor:  AM88 LP A basic AM transmitter kit from North County Radio. http://www.northcountryradio.com/Kitpages/am88.htm |
T.R.F. RADIOS PART 1
T.R.F. RADIOS PART 2
T.R.F. RADIOS PART 3
T.R.F. RADIOS PART 4
T.R.F. RADIOS PART 5
T.R.F. RADIOS PART 7
LINKS to Other Great Websites >
RESISTOR COLOUR CODES
AND CAPACITOR CONVERSION TABLE
T.R.F. RADIOS PART 2
T.R.F. RADIOS PART 3
T.R.F. RADIOS PART 4
T.R.F. RADIOS PART 5
T.R.F. RADIOS PART 7
LINKS to Other Great Websites >
RESISTOR COLOUR CODES
AND CAPACITOR CONVERSION TABLE
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