315mhz/433mhz transmitter
 

hi
i'm just new to this field and i need some help on it and i appreciate any help...
my aim is to make a 315 or 433 transmitter and receiver so what ics is the best for that and where can i buy them and so for the antennas(but i would like to build them)...
thanks

315mhz/433mhz transmitter
 

On Thu, 19 Jul 2012 23:20:02 +0000, foxbrain
wrote:


hi
i'm just new to this field and i need some help on it and i appreciate
any help...
my aim is to make a 315 or 433 transmitter and receiver so what ics is
the best for that and where can i buy them and so for the antennas(but i
would like to build them)...
thanks


For the antenna use a piece of wire, a length of lamda/4 is fine.

w.

is it a straight wire or curved ? shouldn't i look at it's impedance and make matching with it ?
what about it's ICs

315mhz/433mhz transmitter
 

foxbrain wrote:

'Helmut Wabnig[_2_ Wrote:
;793671']On Thu, 19 Jul 2012 23:20:02 +0000, foxbrain
wrote:
-

hi
i'm just new to this field and i need some help on it and i appreciate
any help...
my aim is to make a 315 or 433 transmitter and receiver so what ics is
the best for that and where can i buy them and so for the antennas(but i
would like to build them)...
thanks-


For the antenna use a piece of wire, a length of lamda/4 is fine.

w.

is it a straight wire or curved ? shouldn't i look at it's impedance and
make matching with it ?
what about it's ICs

If you want meaningfull replies, you need to ask meaningfull questions.

What do you intend to transmit, modulation type, power levels, etc.?

i want to make a remote control for 3 relays using the encoders/decoders: pt2262 and pt2272 , it doesn't mine what kind of modulation...
i recently found these 2 ics : u2741b and ata3741 . but what kind of antenna do i need? is there any other thinks i have to know?

315mhz/433mhz transmitter
 

On 7/20/2012 9:44 AM, foxbrain wrote:
'Helmut Wabnig[_2_ Wrote:
;793671']On Thu, 19 Jul 2012 23:20:02 +0000, foxbrain
wrote:
-

hi
i'm just new to this field and i need some help on it and i appreciate
any help...
my aim is to make a 315 or 433 transmitter and receiver so what ics is
the best for that and where can i buy them and so for the antennas(but i
would like to build them)...
thanks-


For the antenna use a piece of wire, a length of lamda/4 is fine.

w.

is it a straight wire or curved ? shouldn't i look at it's impedance and
make matching with it ?
what about it's ICs




Use lots of ICs. It doesn't matter which ones. Just put a lot in.

315mhz/433mhz transmitter
 

On Sat, 21 Jul 2012 14:02:29 +0000, foxbrain
wrote:


i want to make a remote control for 3 relays using the
encoders/decoders: pt2262 and pt2272 , it doesn't mine what kind of
modulation...
i recently found these 2 ics : u2741b and ata3741 . but what kind of
antenna do i need? is there any other thinks i have to know?

Yes, thinkalot.

Why not buy such a thing as this he

http://tinyurl.com/c2pku44


w.

315mhz/433mhz transmitter
 

On Thu, 19 Jul 2012 23:20:02 +0000, foxbrain
wrote:

i'm just new to this field and i need some help on it and i appreciate
any help...
my aim is to make a 315 or 433 transmitter and receiver so what ics is
the best for that and where can i buy them and so for the antennas(but i
would like to build them)...

This sounds like a school class project. If so, we should not be
doing your homework as you will not learn anything.

Some general direction:
http://www.linxtechnologies.com/en/products/modules/kits
http://www.rfsolutions.co.uk/acatalog/RF_Development.html
http://www.ti.com/tool/cc1101dk433
http://www.radiotronix.com/products/proddb.asp?ProdID=216
etc. Google for "433 MHz development kit". These development kits
are NOT cheap, but will give you a clue as to what's involved in the
product development.

For antennas, Google for "433 MHz antenna". There are plenty to
choose from. Most likely, a 1/4 wave wire whip antenna will be
sufficient.

For antenna design help, Google for "433 MHz antenna design". This
might be useful for comparing different types of antennas:
http://www.ti.com/lit/an/swra161b/swra161b.pdf

i want to make a remote control for 3 relays using the
encoders/decoders

There are also commerical products that do roughly what you propose.
Reverse engineering the design and using similar components for your
project is possible:
http://www.ebay.com/itm/170740349762
http://www.ebay.com/itm/170854388957
etc...


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

315mhz/433mhz transmitter
 

foxbrain wrote:

i want to make a remote control for 3 relays using the
encoders/decoders: pt2262 and pt2272 , it doesn't mine what kind of
modulation...
i recently found these 2 ics : u2741b and ata3741 . but what kind of
antenna do i need?

How would anyone here know that as it depends on what kind of range you
exepect to get.

The simplest antenna would be a quarter wavelength piece of wire.

is there any other thinks i have to know?

Probably.

thanks that helped...
BTW i'm making a project for my own not any kind of homework.
i have one more question : if i wanted to make my device have a bigger range like 500-1000meters should i put an amplifer before the antenna?
i should change the antenna in to yagi shouldn't i?