I am a digital engineer by education and practice. However, something possessed me lately and I have a new found love for RF. I would like to start designing radios and have amassed a good number of RF books.
1) Is it doable?
2) Can I work up the knowledge just by reading books and experimenting. I'm interested in designing RF circuits not just home-brewing stuff from magazines or buying ready made equipment.
3) Any suggestions for RF/Radio beginner newsgroups and forums.
I appreciate any information / encouragement / reality checks etc.
sessed me lately and I have a new found love for RF. I would like to start designing radios and have amassed a good number of RF books.
'm interested in designing RF circuits not just home-brewing stuff from mag azines or buying ready made equipment.
1.) Of course it is doable. It is much easier if you work for a company which has a network analyzer, signal generators and a spectrum analyzer... Having access to those items is almost a necessity. Another question to ask is do you want to design low level RF circuits or are you more interested in RF systems?
2.) Well, I guess I see that you are interested in RF circuits....The thing about RF is that the circuits and systems kind of go hand - in - hand, especially if you are interested in radio. For, instance, Noise Figure management is more of a system issue, but you need to know it if you design a front end filter/amplifier. If you work for a company which has RF needs then find some way to shoehorn into this.
3.)I have a website which teaches smith chart / reflection / and the principles of noise using interactive flash programs (It also has other topics) It is here:
me lately and I have a new found love for RF. I would like to start designing radios and have amassed a good number of RF books.
interested in designing RF circuits not just home-brewing stuff from magazines or buying ready made equipment.
If you don't know that stuff already, you should give yourself the equivalent of a "Signals and Systems" course: Fourier transforms, spectra, modulation, impulse response, filtering, convolution, I/Q processing, detection. And learn some about noise. And digital filtering.
A little theory along these lines is very helpful, even if it mostly builds qualitative instincts.
Maybe somebody here can suggest some books that cover this basic theory. If you're a digital guy, you may not have been forced to learn this stuff.
--
John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators
Are you wanting to change careers, or to build radios as a hobby?
Either way, get a copy of the "ARRL Handbook" (and if you end up using it, plan on getting a new copy every five or ten years). It's filled to the gills with practical information. It shies away from theory, so if you need theoretical underpinnings then you need to pull out your circuits & systems books from college.
Wes Hayward's books on RF design are useful, too.
If you want to do this as a career, and if you're close to a university that has appropriate classes, consider taking them. With a decent prof you'll learn ALL the theory in depth, and when you're done you'll have a piece of paper to wave at HR to "prove" that you "really know it".
--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
I actually built a number of them. This is what actually got me hooked. I a lso bought an superheterodyne AM kit that I soldered. That sealed the deal for me, I wanted to design those things and play with them not just solder them.
I do have access to signal generators and a high end oscilloscope, and some what limited access to a spectrum analyzer, but no access to a network anal yzer. I'm sure my company has one or more somewhere. I just don't think the re is any good reason they would give me access to it.
both actually. Whole receivers and transmitters. Not necessarily with the g reatest performance, but functional enough.
Thanks much. I'll check it.
lent of
impulse
me
ds
If
I have studied some of that in school, and self studied some of the rest. B ut not with enough rigor or application.
Just a hobby. I still love digital work and I thinks it fits better with my brain and current experience. But the idea of transmitting and receiving v oice and data over a distance is very fascinating to me. I always loved rad ios and analog electronics just didn't have the right mentorship at the tim e to take it as a career. Neither did I have the very early kickstart that most analog and RF guys will tell you stories about. I still managed to get myself a bit more educated about analog and now about RF. I built a few os cillators and amplifiers, designed and built an OpAmp out of discreet trans istors, and have played a lot with LTSpice.
I do have both books and I'm struggling so much through them but I'm learni ng. It takes several readings sometimes.
brain and current experience. But the idea of transmitting and receiving voice and data over a distance is very fascinating to me.
If you are interested in RF voice and data, it's mostly digital anyway. For voice, it's probably bluetooth. For data, 802.15.4 (packet radio) might be more suitable, especially for point to multi- point network. BT is lossy, where you don't care about dropping some bits. 802.15.4 can deliver reliable data packet, but unreliable latency.
bought an superheterodyne AM kit that I soldered. That sealed the deal for me, I wanted to design those things and play with them not just solder them.
limited access to a spectrum analyzer, but no access to a network analyzer. I'm sure my company has one or more somewhere. I just don't think there is any
greatest performance, but functional enough.
of
impulse
not with enough rigor or application.
brain and current experience. But the idea of transmitting and receiving voice and data over a distance is very fascinating to me. I always loved radios and analog electronics just didn't have the right mentorship at the time to take it as a career. Neither did I have the very early kickstart that most analog and RF guys will tell you stories about. I still managed to get myself a bit more educated about analog and now about RF. I built a few oscillators and amplifiers, designed and built an OpAmp out of discreet transistors, and have played a lot with LTSpice.
It takes several readings sometimes.
Fun book "Build Your Own Transistor Radios" by Ronald Quan. I just bought a copy for my grandson.
--
John Larkin Highland Technology, Inc
jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro acquisition and simulation
Hayward has a book titled "Experimental Methods in RF Design" or some such -- it's supposed to replace the old "QRP Handbook". I haven't seen it, but by reputation it's a good book if you're not steeped in RF design already.
Learning the stuff _is_ an uphill battle -- but the view from the top is great. You might want to get an amateur radio license -- then you'll be able to legally work at frequencies that'll let you get around the world with a five watt transmitter.
(I've got an amateur license -- KG7LI -- but I've kind of lost interest in radio these days. The primary attractor was building my own radios, and now that's too much like work. So I compete in model airplane contests for fun instead).
--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
mewhat limited access to a spectrum analyzer, but no access to a network an alyzer. I'm sure my company has one or more somewhere. I just don't think t here is any
Most companies are enthusiastic about engineers learning more. I would find out if your company has a network analyser and get to know the people that use it. They are the ones that will either help you or claim you may damage an expensive piece of gear.
I'm glad I have all the books recommended so far. I have Ron Quan's book an d I like it a lot. I hope he will have a new version for FM. I also got Exp erimental methods and I'm learning slowly from it but I think it's still go es over my head. I personally think Wes Hayward is a great RF engineer but not a very good teacher, but this is just my impression that could be prema ture. I used to hate the Art of Electronics style of writing and explanatio n until it grew on me and I gained some more knowledge and experience (whic h is still little).
Would I be able to build receivers without a license? How about low power t ransmitters? As for model airplanes I always tell my friends that model air planes will be my retirement hobby. There's so much fun to have with Digita l, Analog, and RF but it seems like a lot of fun too I'll save it for retir ement.
John Fields wrote:
Thanks for encouragement. Maybe I should have better phrased the question a s, is it doable when you're not having it as a career? I am willing to inve st the time, but if that means years and years of study without much financ ial gain then may be I will reconsider. It's a hobby but I don't expect to put as much time as I'd put in my real job or if I'm getting a degree in RF . A hobby is a fun side activity.
I'm glad I'm in the right place. I thought the community here is more focus ed on Analog design but it seems there are enough radio and RF gurus here.
magazines or >buying ready made equipment.
I'm interested in designing and building AM and FM radios out of discreet c omponents with acceptable performance. Then may be I could move to transmit ters and receivers for sending voice over small distances or remotely contr olling electronics. I would then try transmitting and receiving over the ha m bands to maybe talk to other people (or a friend that I will loan my equi pment). Somewhere along this line I'd like to experiment with Software Defi ned Radio and DSPs and perhaps eventually move digital functionality to an FPGA. On this note I have to say I was inspired by SDR project built by the self-taught Jeri Ellsworth that she posted on youtube.
My ambition throughout all this is to home brew everything or most of it, a nd make things out of discreet components rather than ICs. Possibly build t hings in modules as I move along and hook up modules to perform the functio ns I'm looking for and work on optimizing them.
Some companies have no budget for training. They expect you to learn everyt hing on the job. They have very tight schedule that any extra-curricular ac tivities outside your narrow focus are considered a waste of time. They hav e very little inter-departmental communication and hostility some times. My company is one of them. I don't know any of the RF guys at my company, and just can't imagine walking over to them asking to borrow their network ana lyzer!
ything on the job. They have very tight schedule that any extra-curricular activities outside your narrow focus are considered a waste of time. They h ave very little inter-departmental communication and hostility some times. My company is one of them. I don't know any of the RF guys at my company, a nd just can't imagine walking over to them asking to borrow their network a nalyzer!
Go over there with something like a whip antenna with a bnc connector on it and tell them that you have wanted to see how the VSWR behaves over frequency and ask them to make a quick measurement. They will likely do it for you , it will take ten minutes and they will probably enjoy showing you. then you can get the conversation going. If you have some other commercial item that already has connectors on it , like a filter, that will work too.
on the job. They have very tight schedule that any extra-curricular activities outside your narrow focus are considered a waste of time. They have very little inter-departmental communication and hostility some times. My company is one of them. I don't know any of the RF guys at my company, and just can't imagine walking over to them asking to borrow their network analyzer!
Find a new employer. That place will kill you, if you have a brain.
In the US, you can build anything that doesn't radiate too much without a license. There are frequency bands where you can build transmitters without a license, but you won't find much activity if you want to try them out by talking to other people.
If you want to build transmitters, then 2/3 of the test for a ham license is pertinent to the technical side anyway: The test is evenly balanced between electronics, radio propagation, and the laws governing amateur radio.
And if you're an engineer, the test is dead easy.
Maybe not gurus, but some of us know our way around.
Get "Experimental Methods". It's probably just as easy to build a suitable ham-band receiver as it is to build an AM receiver (particularly if you stick to direct conversion the first time or two). If you're willing to learn Morse Code you can make a one- or two-transistor crystal transmitter that'll work nicely.
Then move from there.
--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?
Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
possessed me lately and I have a new found love for RF. I
books.
interested in designing RF circuits not just
Assuming of course that there is still some local AM BC service in the country in which the original poster lives in.
But in reality, what do you learn by building a crystal receiver ? That the loaded Q and hence varies depending of the loading of the resonant circuit ?
A direct conversion HF receiver would be much more rewarding, one could experiment various frequency sources, such as VFO, PLL and DDS, especially since the OP has background with digital electronics.
The same principles apply for I/Q receivers common in WLAN devices.
On a sunny day (Fri, 22 Mar 2013 08:47:28 +0200) it happened snipped-for-privacy@downunder.com wrote in :
possessed me lately and I have a new found love for RF.
books.
interested in designing RF circuits not just
Well there are here, and I am sure in Merrica too. And at night you would hear from other places anyways.
Detector demodulator filter How an earphone, headphone, whatever have you to listen to the 'electricity' works, how much energy it needs to produce something you can hear, etc etc. What side of a soldering iron to hold in your hand, Lead and leadless. How to wind a coil, Selectivity Signal levels antennas detector types (Ge, Si, whisker ;-), Scot-thing, etc.
That later, after he has wound a coil himself.
Na that is later, he would not even know what those words mean. No chips for starters.
You base on experience, but here we have a 2 year old learning tronics.
Once he get some ideas , I agree with Tim I think it was, worth buying that ARRL book, but they have a good website too. And indeed the web and google is your port to education here too.
And you have to have that in your genes I think, want to do electronics. It is constant learning experience that does no tend after you leave university, on the contrary, there is no filed that I know about that has not evolved faster then electronics and communications. Lots of fun and space for invention, experiments, and a big money sinkhole it can be too. Especially if your stuff goes BOOM all the time, except for speakers of course.
After that crystal radio he probably want to up the volume first. So then a side road, audio amps, with a bit of (bad) luck he never returns from that side road.
I mean its like a tree, so many intersections and branches.. You've got to walk them all sometimes, but we only live so long.
See, after you build the crystal radio, and maybe even added a RF preamp, you will KNOW why the superhet was invented etc etc.
Transmitters later? You can build a simple 1 transistor FM transmitter with good quality, it is hard NOT to make it work.
Too long a story to tell here. Just start the * journey.
Do not be the arm chair traveller, who never leaves and only watches folders. Hey!
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.