Hi everyone.
I have an old pair of transmitter and receiver. On the transmitter theres a SAW resonator.
Now, i found an other newer pair online but there is no SAW resonator. Theres a 13.560M Crystal Oscillator.
How does that work? How is it possible to work without resonator?
Id be happy if anyone could provide schematics so i can make it on my own.
Thank you!
hmm i wonder if we could answer better if we had links and knew what you were talking about. In fact, just blindly looking online to try to find what you are looking at seems like a waste of time
this is what I found it has a 433 Mhz resonator on the transmitter. The resonators are not expensive but I have no idea what you mean.
You have to post some information about the "newer pair online" to get a real answer. Just giving the crystal frequency isn't helpful. I have a collection of 433Mhz schematics if you can come across with some info.
Devices with a resonator typically have an oscillator at the transmit frequency and it is simply turned on/off to transmit a coded signal. This is the case with the FS1000A pictured in post #1 above.
Devices with a lower frequency crystal typically have a phased locked loop synthesizer that generates the transmit frequency (or some related local oscillator frequency). The advantage of this approach is that the frequency can often be tuned to many different channels without employing a separate resonator for each. This a much more sophisticated approach, but given the state of the art in RF integrated circuits, radios of significant complexity can be built on an inexpensive integrated circuit. One example common in the Arduino world is the HC-12.
If you're looking to reproduce a particular radio, figure out what is the core IC is and the manufacturer of that IC will probably have published reference designs in the data sheet or application guides. That said, unless you're building significant quantities, it usually makes more sense to use a prefabricated module.
Hi everyone.
I found online that "new ones" use syn115 chip for transmitter and syn480r for receiver.
What posted walframore is the old ones that I have with the SAW resonator.
I found schematics online. I ordered them from China. Have to wake 1-2 months now to try..
I couldn't find them in Europe or USA. Only ready made boards with those chips. But I need the chips so I can add them On my prototype.
Does anyone have any other better suggestion to use for transmitter and receiver at 433mhz?
Are those supposed to work for long distance like 20 meters? Or 10 with walls in between?
Thank you!!!
did you understand the message?
chris700:
Hi everyone.I have an old pair of transmitter and receiver. On the transmitter theres a SAW resonator.
Now, i found an other newer pair online but there is no SAW resonator. Theres a 13.560M Crystal Oscillator.
How does that work? How is it possible to work without resonator?
Id be happy if anyone could provide schematics so i can make it on my own.
Thank you!
Firstly a quartz crystal is a resonator, a very accurate one, so no problem there.
32 times 13.56MHz is 433.92MHz, so clearly the transmitter is multiplying the frequency of the crystal by
a factor of 32, probably using a VCO and PLL. Crystal oscillator frequencies can be slightly modified (known
as "pulling") allowing the signal to be frequency modulated by a signal (FSK). And of course an oscillator can be turned on and off allowing on-off keying (OOK).
I've also seen versions that use a 64x multiplier... I'm not seeing good reviews about this version although I like superheterodyne, just not much transmit power. It will need a good antenna to be usable.
wolframore:
It will need a good antenna to be usable.
Yes, however, a good antenna is easy. Just a 95% of a quarter wavelength of wire.
bonus points if you know the length
MarkT:
Firstly a quartz crystal is a resonator, a very accurate one, so no problem there.32 times 13.56MHz is 433.92MHz, so clearly the transmitter is multiplying the frequency of the crystal by
a factor of 32, probably using a VCO and PLL. Crystal oscillator frequencies can be slightly modified (known
as "pulling") allowing the signal to be frequency modulated by a signal (FSK). And of course an oscillator can be turned on and off allowing on-off keying (OOK).
Hi my friend.
Thank you and all the people for your replies.
Do I need to flash any code on those chips syn115 that I bought or they are all ready flashed and ready to Do that job? I found the schematic of syn115.. Do I just make it on a breadboard etc and then just "feed" It from an arduino board?
Thanks everyone
chris700:
Hi everyone.
I found online that "new ones" use syn115 chip for transmitter and syn480r for receiver.
What posted walframore is the old ones that I have with the SAW resonator.I found schematics online. I ordered them from China. Have to wake 1-2 months now to try..
I couldn't find them in Europe or USA. Only ready made boards with those chips. But I need the chips so I can add them On my prototype.
You'be better off using a premade RF board as a daughterboard, RF design is not a beginner's game.
I'd suggest looking at transceivers like the RFM12 RFM22 etc, which are much more civilized in their
use of bandwidth and flexibility. Many of these small modules can be surface-mounted direct to a host
pcb.
Does anyone have any other better suggestion to use for transmitter and receiver at 433mhz?
Are those supposed to work for long distance like 20 meters? Or 10 with walls in between?
Thank you!!!
RF range is a function of frequency, RX sensitivity, TX power, modulation bandwidth, antenna gain, and how
quiet the band they use is.
thank for your advises.
I will try to buy those boards and try them since they will prob offer better range however since I can find the bellow schematics and chips online, if i make them on the breadboard would they work as is or they would need any code into the chip to be uploaded by me?
Thanks!!
Best Regards
aarg:
Yes, however, a good antenna is easy. Just a 95% of a quarter wavelength of wire.
Ideal length depends somewhat on the wire thickness, and the nature of the groundplane it works against.
Without a groundplane its more like guesswork!
Thank you for finally sharing images it helps to save time for people trying to help you when you share information.
How did you come to the conclusion they have better range? Better range than what? How far? That chip puts out 10 dBm max, the others are 20 dBm.
Radio circuits do not do well (don’t work) on breadboards where every bit of inductance and capacitance affect your resonant frequency. But perhaps you should try it.
MarkT:
Ideal length depends somewhat on the wire thickness, and the nature of the groundplane it works against.
Without a groundplane its more like guesswork!
I have some great books on the subject wish it was as easy as just attaching a piece of wire.
wolframore:
Thank you for finally sharing images it helps to save time for people trying to help you when you share information.How did you come to the conclusion they have better range? Better range than what? How far? That chip puts out 10 dBm max, the others are 20 dBm.
Radio circuits do not do well (don’t work) on breadboards where every bit of inductance and capacitance affect your resonant frequency. But perhaps you should try it.
Hi my friend. Thanks or your post.
In the past i ordered from somebody a pcb design of one board.then i uploaded it in one website and i bought the prototype. The board arrived to me and then i had to solder the parts. Those parts were big enough to solder them on my own.
On the board that im trying to design on my own(first time) i will try to include that schematic so i can order the prototype and try them on a real board and not on a breadboard because as you said it might have issues.
However those parts now are so small/tinny that i cannot solder them on my own.
Is it possible to suggest me a place where they do the prototype of the PCB but they also solder the parts?I would prefer them to get the parts and not expect me to send them to them.
Thanks
I’m not sure who will solder one board for you.
Hi everyone.
Why everything has a value on that schematic but not what i point with the red arrow? If thats because this is the antenna then why antenna is connected to 2 points? All antennas i know are connected to one point and the other one is not connected anywhere lol.
Also what is the 2 to 3 arrow that i point with the blue line?
thanks everyone for your help
Its a PCB antenna, its written there for you!
If you don't understand RF electronics you will be blundering in the dark here, the normal rules of low
frequency electronics completely breakdown as Kirchoff's laws no longer work as approximations, you have to understand the full repercussions of Maxwell's equations, especially for antennas, where layout and stray
reactances are completely dominant. Rather than thinking of currents going round circuits you have to
consider the electromagnetic waves and fields in space between things.
