How to connect RF transmitter directly to reciever?
How to connect RF transmitter directly to reciever?
(OP)
Hi everyone, I've got a problem that I need some help with. I've got a wireless transmitter and receiver setup (315Mhz) that controls a hydraulic valve system. The problem is that sometimes we need a wired solution. We've got a wired system, but it is a bit old and cumbersome. I had the brilliant(?) idea of using the wireless transmitter as both the wireless and wired controller by running coax between them. Now, my question is, how can I go about hooking the transmitter's antenna output directly to the receiver's antenna input? I'm afraid that the TXs output is probably too large for the RXs input and it'll just fizzle. Am I right in thinking this? Can I avoid this problem by simply placing a resistor inline to attenuate the signal enough for the RX to receive without blowing up? I went ahead and tested it without any attenuation and nothing bad happened, but I need to be sure problems won't develop if I don't attenuate the signal.
The TX output power is typically around +2dBm and the RX sensitivity is -102 dBm.
These are the data sheets for the TX and RX we use.
TX http:// www.linxte chnologies .com/docum ents/TXE-x xx-KH_Data _Guide.pdf
RX http:// www.linxte chnologies .com/docum ents/RXD-x xx-KH_Data _Guide.pdf
Thanks for any help anyone out there can give me. I'm not particularly knowledgable about RF systems, but I know just enough to be dangerous.
The TX output power is typically around +2dBm and the RX sensitivity is -102 dBm.
These are the data sheets for the TX and RX we use.
TX http://
RX http://
Thanks for any help anyone out there can give me. I'm not particularly knowledgable about RF systems, but I know just enough to be dangerous.
RE: How to connect RF transmitter directly to reciever?
You'll want more than the minimum signal at the receiver, thus you don't want the full 104 dB attenuation as the simple math might indicate. More like 30 to 60 dB range (a guess). If the cables are very long, then also account for the cable loss; but that is probably a trivial detail for any reasonable cable lengths.
Since +2dBm is only a bit more the one milliwatt, it is low enough that it is not likely to cause any damage even if connected directly. Depending on the receiver, direct connection might be too much due to receiver performance issues, thus some reasonable attenuation would be a safer bet than none.
Any reasonable receiver will provide sufficient dynamic range that you don't need to over analyse it. It's a very wide target (like the side of a barn from 10 paces). And with +2dBm would don't need to concern yourself with power ratings.
Note - I didn't look at the reference data sheets...
RE: How to connect RF transmitter directly to reciever?
Thanks again.
RE: How to connect RF transmitter directly to reciever?
kch