How to start learning about transformers

Very interesting thread.

Maybe to look some materials about "transformers interference with radio waves and impact on radio receivers".

First try to search old cheap chinese devices and test it, maybe you already have that in house.

I have one old PS/2 keyboard, which when typing make interference on specific FM radio freq.


Best regards,
Peter

yes its intresting to design fm tsr work on it

What do you mean transformer which sends sound on FM radio waves ?

I mean I want to make a transmitter which works at special frequency so I can receive transmitted data(for example my voice) by radio waves.

you know each transmitter needs a receiver,in fact I want just make the transmitter an use radio as the receiver part.

for example I speak by transmitter and another person can hear my voice on radio.

I suspect that there is a language difficulty here; perhaps the OP means "Transmitter".

Ooooh yeeeeees I made a mistake,I'm really so sorry.
Thank you my friend "krp" for your attention.
I will edit posts and correct my mistakes.I should write "Transmitter" instead of "Transformer".

Ok now i read every transformer as transmitter...

Its really interesting topic for every new comer to electronics... I also did a FM transmitter in BE second year mini project and its worked awesomely around some 100ms and I really enjoyed, If I got that circuit I will post it here.........

I'm really happy and grateful for your interest about this topic,I hope it would have a good out come at last and help me and other students learn more about it.

OK
for the first step I think it is better to discuss what parts a transmitter includes of and what we should learn to make it.
If anyone have a simple circuit which helps us to start please post it.
Thanks alot

I searched and found this circuit

http://www.boondog.com/tutorials/rfT...ransmitter.htm

take a look at it and tell your ideas,Is it good to start with?

Try this IC :

Building a transmitter is fun, but illegal in most countries and not a real starters project. Most schematics are called bugs. They transmit in the 3 meter FM band but are not real FM transmitters. Basicly the schamatic you gave is nothing more as an oscillator that transmits a mixture of AM and FM. It is unfiltered so it transmits at 100, 200, 300 MHz etc upto > 1000 MHz.

A real transmitter has much more parts. They have things like oscillator(s), modulator, discriminator, BFO, mic amplifier, mixer, IF amps, band and lowpass filters etc. Radio is one of the most difficult parts of electronis. You need good component knowledge, for most about paracitics, network theory, AC theorie (about EM waves, reflections, complex impedance) and regulations about how to use one.
If you are serious about this contact a local Ham group.

But it is fun to start with a FM bug. The only problem is that it often dowes not work the first time. If you have a decent scope, lcr meter and a spectrum analyser it is often easy to get it working but without them it is just gambling and hoping it works.

I agree with Peter, first build a receiver to get some practice. A receiver that is on a totally wrong frequency often still receive something, a transmitter that is running at 70MHz because you have just a bit to much paracitic capacitance looks like it does nothing but in the mean while it is transmitting at 70, 140, 210 so there will be a good chance you are transmitting at some air traffic or army frequency. So never use an antenna. (but that depends on the country, in some countries you can do everything, in others you can end up in jail for illigal transmitting) This is not to be an old fart, but not everybody knows this so I think it is important to know. What you do with it is up to you. Here are some bugs, one of them I redesigned to be real FM and filtered: http://www.pa4tim.nl/?p=1528 Text is in Dutch but the pictures tell enough (or use google translate, a lot of my site is allready in english)

What is your knowledge level ? What have you allready build, what gear you have ?

yeah that was a disadvantage in complicated circuits you are not going to know what you are doing, but Its often ends with no results If you are a very very beginner then construct 555 circuits they are also interesting...

how could you make a LED blink with a DC source.... try it and try to adjust the timings.......

What is Ham group?

I?m undergraduate student of electronic engineering, I have passed 4 semester of university.

I want to be an analog designer in the future so to start I decide to work on transmitters.

In fact as you know electronic is known as difficult field between engineering fields, but I believe it isn?t so difficult provided that you don?t study just it?s theory, and try to do experiments as much as possible to make it interesting and easy to understand.

Thus I decided to choose designing transmitters as my goal and then learn a lot of my lessons under this project. As you said transmitters include many parts that each of them is really essential for an analog designer to learn.

In summary my purpose is learning analog through experiments and making a device (not just make a transmitter or receiver)

I think now you can show me the way? Am I in the correct way or I will miss my goal?

Best regards

A HAM is a licenced radio amateur. I'm a HAM and my callsign is PA4TIM. I have a full licence ans we have parts of the frequency spectrum that is reserved for HAM radio, some parts we join with other users. The lowest band is 500 kHz the highest way in the GHz. But we are not allowed to make radioshows with music like a broadcast station. We can talk, use CW (morse), some digital modes and amateur television.

Hands on experience is indeed important. That is if you build things and try things and try to think about why something works or not .

I would say choose a schematic, build it and analyse it. And if you get stuck, ask here.

But I would not start with radio. Better build an audio amplifier. You do not need exotic gear for that. You learn the most from measuring (and my favourite, repairing test equipment) and every cheap analog old scoop, even the oldest one is able to measure audio. Even a computer with soundcard and some freeware programs can be used. You can build filters and use the computer with something like JAAA or other audio analyse program and the noise it generates to sweep those filters.
If you want to learn radio you need a high bandwidth scope, terminators, good quality coax, good probes, dummyload, swr meter or better spectrum analyser.
However, it is possible. I started with radio too, my first project was a receiver I designed my self around an IC, something like is given in this topic. It did not work but it was for 14 MHz and my scope was usefull for this. I learned a lot from it. My first transceiver was the bitx20, this is a project from someone from India and well documentated, but not something to start with. I was building receivers and repairing gear for two years when I build that. Most things I do is repairing test gear (I'm now repairing a spectrum analyser, but I have build one myself too) and analog design regarding measurement gear. Besides that I'm a voltnut (I have a lot of calibration gear) and network analyse junky (I have several vector network analysers)

Would you please give some explanation about these schematics?
They are transmitters or receivers? and what kind(FM or AM ...)?

Thanks a lot

the above schematic of tpeter is of fm transmitter

@Nadiro

FM frequency range. AM have different range of frequencies. If you look bottom side of second illustration you can see FM freq range 89-109MHz.

MAX2606
http://www.maximintegrated.com/datas...ex.mvp/id/2323
http://datasheets.maximintegrated.co...X2609EVKIT.pdf



Best regards,
Peter



http://electronics-diy.com/vhf-fm-transmitter-max2606.php
http://electronics-diy.com/electronic_schematic.php?id=817
http://people.virginia.edu/~ll2bf/docs/various/fm_xmtr.html



http://pandatron.cz/?916&miniaturni_usb_fm_vysilac

http://www.google.nl/url?sa=t&rct=j&...51156542,d.d2k
The datasheet.
I now see it are transmitters. Overlooked that the first time. Nice little IC. It is a vco, a voltage controlled oscillator. So not a transmitter but you can use it for that. But it has a 6 pin sot23 housing so you need to make a pcb and use smd parts. Not bad because that is the future. Not easy too.
T1 and the zener are the voltage regulation. The zener is 4,7V. A base-emitter junction of a transistor has a 0.65 Voltdrop. So the emmiter will be 4,7-0.65 = around 4V.
R3, C1, P1 and connected other parts fiorm an interface to the IC, This is the tuning voltage input and by adding an AC audiovoltage to it you change the frequency. This is called FM. Frequency modulation. If it was AM you would have to change (modulate) the amplitude of the carrier (the oscillator signal)

Up to here I appreciate your participation in this topic.

In summary:
Peter said: “try to make a transmitter”
Venkadesh_M suggested: “construct 555 circuits”
PA4TIM proposed:” build an audio amplifier”

Now as a beginner I really don’t know what should I do and what is the best way to start learning about analog!
Please come here and tell your ideas, discuss and advocate about your’s and other’s suggestions and help me to make the best decision.

I am very very happy to have friends like you are.
Thank you for all your answers.

Have a good time