- July 12, 2009 at 4:41 am #7298gccradioscienceParticipant
Total posts : 12
I have been learning electronics for a long time using simple basic electronic lab kits. I have built many times the AM Broadcasters using the 200 In One Lab Kit. I think its a great tool to learn the most simple transmitter and how it works. I like tinkering with electronic circuits. I feel that we need to find ways to add more parts and extra circuits to make the sound quality better and perhaps better range. If someone has not built a kit before and wants to get their feet wet in AM transmitter electronics, the basic electronic lab kits with spring terminals are the way to go.
I hope I can meet other electronic lab kit transmitter broadcasters on this forum. I am very sorry that I don’t have a X-Pro part 15 transmitter for over $500.00 and since the prices are going up, I might not be able to obtain a X-Pro transmitter for a long time. I experiment on a very low power nano range less than 10 feet on 540 kHz trying to improve modulation quality and do other experiments. I tried other frequencies such as 1620 kHz, but I don’t think I got that range to tune, just harmonics of 1620 kHz so just to be safe I reside on 540 kHz. When I first built the AM transmitter on the 200 In One the circuit came with a cheesy sounding small 8 ohm speaker mic. Makes a great intercom for to call another AM radio! I have been experimenting now on the small PNP transistor
RF amp and got amazing results with hooking up a speaker crossover with 3 resistors and
then use a audio amplifier from an old small stereo receiver. Still the range is poor and very local, but in a very safe distance not to interfere with other stations. The range measures less than 100 feet.
GCC Engineering @ HomeJuly 13, 2009 at 3:37 am #17439PhilBGuest
Total posts : 45366
There is another tool available (for free) to test circuit operation and see the effects of design changes. It’s the LTspice IV circuit modeling program. This is a full implementation of the venerable Spice electronic circuit modeling software. You can download it absolutely free at http://www.linear.com/designtools/software/ltspice.jsp
I know, I know … Many people here will probably be intimidated at first by the complex capabilities of this program, but at least give it a try. You can quickly enter a simple schematic and run it immediately. You don’t have to be an electronic engineer. Just stick to the basic functions at first, then build on that if you like it.
The advantage is that you can enter your circuit on the graphical schematic page and then hit run and view the waveforms at any point in the circuit, just like a scope. Its a heck of a lot faster than connecting components on a Lab Kit. If you accidentally short power to ground, there is no smoke! 🙂 It doesn’t even stress your computer!
There are a number of example circuits included. You can get your feet wet with one of the simpler ones. A neat feature I have tried and found very interesting is that you can drive a circuit from a .WAV file or write the output to a .WAV file. As long as your circuit works in the audio range, you can play back the .WAV file after running the simulation and hear exactly what the circuit produces.July 14, 2009 at 12:13 am #17441rock95sevenGuest
Total posts : 45366
My parents saw potential in me and I started learning electronics using many 30-in-1 kits etc. My favorite has to be the Heathkit 30-in-1 kit with springs, more code key, meter and external speaker.
I built intercoms, amplifiers, alarms and my favorite AM broadcast station.
In fact i think i had a roll of over 100 feet of thin wire my dad gave me and used that for a very long wire in the backyard hanging between a tree and my bedroom window. The ground was connected to a old steak driven into the ground where a lighting arrestor used to be.
At the time i didn’t realize that my long wire antenna was illegal but is sure got my signal out there. At least a mile of coverage! Audio was rough since i modified the kit to take audio from a reel to reel machine.
Later that same kit served as a community radio station covering 1/4 using a car antenna from a buick (telescopic kind) and the aluminum flashing as a ground on the roof.
All that fun and education came from a kit built in the mid 1950’s.
There’s nothing wrong with the way you do things and as long as it brings you happiness and you learn electronics along the way, then by all means press on.
Enjoy your stay here and feel free to ask questions.
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