radiowave

zera

hi.....

everyone can help me......

i have a few question about radiowave......

1. how to use a simple schematic about radiowave?
2. what means about radiowave?
3. what min voltage for draw a simple schematic radiowave?

LoopyByteloose

Hi Zera,
There seems to be a language barrier here. Often non-native English is just too general or too vague.

I am guessing the following:

By 'radiowave' you really mean electronics.

If that is so, your questions begin to be understandable.

1. Schematics are a system with its own vocabulary. The lines represent wires and the symbols represent devices.
You need to learn what each device can do before you can easily understand a schematic.

2. [noparse][[/noparse]I just cannot under stand the question}

3. While I am again unsure about your question, most of the digital electronics require at least 3.3volts.
LEDs are about the only thing that is useful and can operate on less than that, maybe 2.2volts.

I am also guessing you are quite young. If that is so, don't worry about your questions sounding odd -- just keep trying and try to improve your English along with your electronics. You will learn two skills at the same time.

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"When all think alike, no one is thinking very much.' - Walter Lippmann (1889-1974)

······································································ Warm regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

Paul Baker

Also you may want to post your questions in your native language (someone here may speak your native language). Also after your post in your native language, you can include a machine language translation, such as the one here: http://dictionary.reference.com/translate/text.html

It sometimes gives the wrong translation too, but it may be close enough for us to understand.

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·1+1=10

zera

Sorry,

I now get a friend to help me re-type the questions :-

I want to design a simple radiowave transmitter to install in my car.

I also want do design a simple handheld radiowave receiver to find my car in a big parking lot.

Can I use the SX to do this?
Anybody got any ideas on simple RF circuits that is easy to understand and assemble?

Thank you.

SPENCE

What country are you in?. For some one to give you answers pertaining to usa and if it turns out you are in britian, the information would be worthless. Radio transmissions are regulated differently in different countries. You need to have information pertaining specifically to your country.

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73
spence
k4kep

william chan

Hi Zera,

I think you can use a low power AM transmitter to avoid problems with the law.
AM is quite directional with a ferrite antenna, so it may be able to tell you the approximate direction of your car.
( with some smart shieldings )

Unfortunately, I am not an expert of RF circuit designs.
Hopefully, somebody else with RF circuit experience can help you.

LoopyByteloose

Zera,
The SX is not a radio transmiter or a radio receiver. It is a microcontroller that is used to communicate between digital devices [noparse][[/noparse]things like computers and computer controlled motors]

Sorry, but this web site cannot directly help you.

SPENCE is a licensed amature radio operator and can answer your questions, but this discussion should be moved to the SANDBOX section of the Forum as it isn't about the SXes.

If someone from Parallax decides to move it, I hope they will email you to let you know where to look.

Warm regards,

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"When all think alike, no one is thinking very much.' - Walter Lippmann (1889-1974)

······································································ Warm regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

dkemppai

Kramer said...
Zera,
The SX is not a radio transmiter or a radio receiver. It is a microcontroller that is used to communicate between digital devices [noparse][[/noparse]things like computers and computer controlled motors]

Sorry, but this web site cannot directly help you.

SPENCE is a licensed amature radio operator and can answer your questions, but this discussion should be moved to the SANDBOX section of the Forum as it isn't about the SXes.

If someone from Parallax decides to move it, I hope they will email you to let you know where to look.

Warm regards,

You might look at these guys...

http://www.linxtechnologies.com/

The have some devices that·do not·require·compliance testing...


-Dan
(N8XJK)
·

Guenther Daubach

I once was thinking of something similar: Having a radio receiver in the car, and a hand-held transmitter with you. In case you can't find your car, activate the hand-held transmitter. The receiver in the car will receive a certain signal in this case and it will activate a horn, a siren, or something else to give you an acoustic feedback. To make sure that the receiver is not triggered by false signals, it is important that the RF (radio frequency) signal is modulated by some unique ID code. So, it may be possible to use SXes for generating and decoding such ID code but this is a different story.

You first need a matching set of transmitter/receiver operating in a frequency range that is free to be used for such remote-control systems in your country. As a beginner, I would not try to build the transmitter and the receiver by myself. Instead, I would buy a set of off-the-shelf units.

Important is that the transmitter can be modulated and the receiver has a demodulated output (both digital, if possible). Also check for the maximum possible range between transmitter and receiver for a good operation, and keep in mind that concrete walls and floors usually found in garages can reduce this range dramatically, depending on the transmit frequency.

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Greetings from Germany,

G

LoopyByteloose

Back in my university beer drinking days I once lost my car for three weeks. A beacon sure would have helped. At least there weren't any parking tickets as it was in a legal campus parking lot, just a bit far from my dorm.

Guenther, my motorcycle has a rf security lock that does all that now. Everybody here has one on their car or cycle.

I was thinking he wanted to get started with walkie-talkies as he mentioned AM.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"When all think alike, no one is thinking very much.' - Walter Lippmann (1889-1974)

······································································ Warm regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

Guenther Daubach

Kramer,

I also have an RF securoty lock in my car but the range between tre transmitter and the car is much too small to use it as a "car-finder".

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Greetings from Germany,

G

william chan

Kramer,

I was also thinking of a RF beacon that transmits for just 50ms every second from the car.
Can you build such a transmitter and a handheld receiver that can be interfaced to an SX?
The SX could rotate the ferrite core antenna with a small motor to get the approximate direction that has the strongest reception.
It could then blink one of the LEDs to show the direction of the car.

Guenther,

I think Zera could be a student who needs to do this project before graduating.
Buying the RF modules off the shelf might not get her good marks for this project.
Are you an expert on RF circuits?

mm

Her best bet is to obtain a set of the proper pre certified RF units, trying to build your own is easy if you have RF knowledge; however going thru cert testing is another thing.

I am an Avionics Rf engineer and just spent close to 50 thousand US bucks to certify a simple avionics wireless link for a wireless headset to a panel mount Avionics radio. This was the FCC transmitter and antenna radiation test cost.
Look at these links and you'll find a lot of info on the various certifications, requirements etc.

http://www.radiotronix.com/support/content_by_cat.asp?contentid=199&catid=114
just an example of what the regulations are like. For example she would need to design her device to comply with standards like this.

http://rfcomply.com/products_services/faqs/


Mike

rcarmel

A better idea would be to use this technology as an "electronic leash" for your kid!· When you are out with your·4 year old in the mall and he is running around and you can't find him LOL

rcarmel

mm

That's actually not to far fetched. I had a contract Engineer helping me out last month and he's now gone but working on this exact idea with a small 2.4 Gig xcvr set with MIMO antennas and a PDA to show the direction.

MM