RF Ghz Mhz and the whole crazy thing

[olliec420]

OK this is kinda but not related to satellite stuff. I have been trying to teach my self about RF and how it travels but there is something I'm missing to make it all make sense.

For instance radar.... now LIDAR i sat down and read and bought equipment and used it in the field and i understand completely how it works, every little bit. RADAR i can't seem to do the same thing with. I am 30 and i have been playing with rf in amazement since i was a little kid. walkie talkies to cable tv.

right now I'm reading about oscillators and i was trying to improve the power output of a device here and when i put move power to it, i got nothing, so i added more power and burnt it up. turns out it was a voltage controlled oscillator so I'm increasing the volts and amps was a mistake, i guess i should have increased the wattage??? i don't know, just an example.

what I'm really looking for is someone here who knows the ins and out, would you be willing to let me bounce some questions off you to help me get an understanding of the basics of how this works and once i have that i think i can run with it i looked for the rf basics on youtube, but their basics were TOO basic ya know what i mean. like i get it but there something a miss.

everyone has always been so helpful in the past i figured this was the best place to fine an electrical engineer who would be willing

 

[FaT Air]

""RF and how it travels "" Just like light. In a straight line. although it can be reflected(your dishes as an example.) It can also appear to bend around corners slightly. The lower the frequency, the greater the bend. Attenuation in free space (Free space Path Loss) is http://en.wikipedia.org/wiki/Free-space_path_loss

Just 'putting more power' to a circuit to 'get more out' has to be qualified with what the circuit, and individual components of the circuit, can dissipate.
https://www.google.com/search?q=power+dissipation+formula

 

[rv1pop]

My advice --- for what it is worth -- study the HAM radio license books, maybe even as far as getting licenses. Those will give you well beyond the basics, and point you to the areas you want to study, and where to study. With this advice and $3 you could get a cup of coffee at McDonalds!
What you did frightened me. Reminds me of the Darwin awards! RF, uncontrolled, is extremely dangerous. What you are describing brought a vision defeating the safety door switch on a microwave oven so you could stick your head into it..... PLEASE learn what RF is and how it works before you experiment too much.
Loosing a college grad scientist to wild power / RF is one thing, but loosing a SatGuy would be a tragedy!

 

[manitobamike]

I'm sure lots of people on here would be willing to answer any specific questions you might have.
Watch your wording if you want unambiguous answers. RF is radio frequency. It is just a descriptive term for the frequencies in a particular band (3kHz to 300GHz according to Wikipedia). In saying that you now know all there is to know about RF.
You need to direct questions specific to transmitting and receiving RF power and signals. For the most part radio waves and audio waves behave in the same way so it is easier to conceive of the modes of transmission and reception if you envision them in this manner. Consider RF as sound waves we can't hear. If your questions are more to how is information carried using RF waves read up on AM broadcasting (AM being the simplest modulation form) and then carry on to FM and FSK.

PS. You may have burned out your oscillator because of reflections.

 

[FaT Air]

On-Off carrier (keying) is the simplest form of conveying information. Be it with smoke, light, audio, or RF. Then it's AM, FM, FSK, PPM, PWM and other 'exotics' like DVB-S and S-2, QAM. ( I'll bet there's more.)

 

[navychop]

On-Off carrier (keying) is the simplest form of conveying information. Be it with smoke, light, audio, or RF. Then it's AM, FM, FSK, PPM, PWM and other 'exotics' like DVB-S and S-2, QAM. ( I'll bet there's more.)

How about the original? A strategic "wink."

 

[. Raine]

Lidar, [lasers, for the most part] and RF are both in the electromagnetic spectrum but act like and are really totally different animals. A laser is coherent light, RF is generally not, unless possibly like maybe a maser, [coherent microwaves]. Rv1pop made a very good point about how RF can be very dangerous. Many devices even though not designed to produce X-rays, microwaves, etc, can, when overpowered.

I never got into ham like he suggested but have some friends that are, that might be a good place to start to learn about RF, or study antennas maybe, also electronic theory stuff like ohm's law, radio wave propagation, etc.

Many times it's not about more power, but rather tuning, resonance, different types of coupling, etc.

More information on what you're doing I think would be needed for anyone to help you, you mentioned radar and an oscillator but that's really too vague to give any advice on really.

 

[olliec420]

Thanks for all the input guys! I got my question answered via pm. But everything else is good info too. Especially pop!

FYI I burned up my oscillator by giving it 12v 2 amps, when it was made for 4.2v 500ma. Some smoke and it was over Lol. Oops

 

[FaT Air]

You've discovered how electronic devices work. Yep, smoke. When the smoke escapes, it don't work no more. Different smoke in different electronic devices. Transistors one kind of smoke, Caps another kind, etc. Get good at it and you can tell what type of part 'burnt up' just by smelling the unit in many cases.

 

[rv1pop]

My suggestion -- I would love to hear you on the ham bands, but I teach the ham radio courses to people who I know will never get on the air -- but some times they surprise me and do get their license. Even if you do not master the information to pass the test, you will understand a lot more than the Wiki basics - which is GOOD. I have taught 80 year old grandmas and 5 year old kids, that learned enough to keep themselves out of trouble. I use books, but there are on-line resources also. Just be safe!