433mhz repeating.

Hello one prblemishes I'm having with the 433mhz transmitters and receivers is range and going through walls. I have a bunch of sensors in different rooms that are battery operated and in sleep most 93% of the time. But being there in different rooms the ones that are future away can't get a signal to the recriver. I was looking g I to maybe possible building some kind of repeater. I have tried different length of wire and moved things around but still nothing. Wouldn't be fees able to making a repeater for it. I have a whole bunch of the 433mhz transmutters and receivers. Maybe I can use them. Can someone help with a fix on my project?

You will get the best range, even through walls, if you use a decent antenna.

I routinely get over 300 meters range in the open with a balanced dipole antenna, as shown below. The antenna is 32.6 cm from tip to tip, with one inner conductor connected to ANT and the other to GND on both the transmitter and receiver.

Switching to the little yellow receivers, the cheap rxb12 ones based on the syn470, will get you significantly better range too (combine with antenna recommendation above for best result)

Hello thank you both. I was thinking of maybe going with a Solid core Wire And instead of having the current wire coil up that is on mine now as i have seen many times online to have just a straight Wire antenna. I will also look into the other chip as DrAzzy said. Thank you

HelloJremington which LCD is that? I'm looking for a small one like that.

How are you powering the transmitter?
Chances are you're underpowering it, and the easiest way to boost range is to just give it more power.

which LCD is that

Complete robot controller, Pololu Orangutan.

i have seen many times online to have just a straight Wire antenna.

That only works if there is a ground plane at the base of the antenna to act as a reflector.

Hello Right now I'm powering with 3 Double AA batteries for a 4.5v I have a arduino pro mini. Also have a Dht22 on it. The pro mini sleep for 15 minutes then wakes up takes a temperature and humidity reading and transmit it back to a receiver base station with another arduino uno board and a small LCD on 5v power adapter.

A Simple Setup. The problem is when doors are closed no signal. When doors are open i get a very week signal. but if i move closer then i get a stronger signal.

The transmitters work on 3-12v, with more voltage = more distance.
The tiny FOB remotes use a 12v battery (just 4 small 3V button cells stacked in series, really) and I've gotten 200meters from those.

I use the RFM22B in most my projects, which is pretty much a vanilla 433 MHz. transceiver. I had a little trouble crossing a whole house with these, so I just set one up as a relay node. Any other unit which is supposed to use the relay node transmits to the relay node's address, with info added to it's payload as to where its headed. The relay node then sends the payload forward to the final destination node. Works very well, and increases my comm reliabilty to 100%.

jrdoner:
I use the RFM22B in most my projects, which is pretty much a vanilla 433 MHz. transceiver. I had a little trouble crossing a whole house with these, so I just set one up as a relay node. Any other unit which is supposed to use the relay node transmits to the relay node's address, with info added to it's payload as to where its headed. The relay node then sends the payload forward to the final destination node. Works very well, and increases my comm reliabilty to 100%.

Relays are relativly easy to set up with these devices, and can as you suggest significantly improve reception.

If your RFM22B circuit is wired so that you have control of the SDN pin (grounding it is bad) then the LoRa RFM98 device is a pin compatible replacement. Different code of course, but you should see a range improvement of between 10 and 30 times, higher noise immunity too.