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315MHz and 434Mhz Tx-Rx..do they interfere??

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msd

New Member
I am trying to communicate two wireless nodes having..

Node1. 434Mhz--Tx..315Mhz Rx..
Node2. 434Mhz--Rx..315Mhz Tx..

I have used ht640 and ht648 as encoder decoder for each wireless line(with different addressing)..
My problem is these two pairs does not work concurrently...they work perfectly when powered alone...but when both are powered together only 434Mhz pair works...I want to communicate to and for at same time...
Does these pairs interferes????
 

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ccurtis

Well-Known Member
Any frequency of sufficient amplitude to enter a receiver’s front end will reduce system range and can even prevent reception entirely. Such may be the case when a transmitter at one frequency is located too close to a receiver of another frequency.
 

ccurtis

Well-Known Member
Really? Would explain a problem I had a while back...how do you avoid this problem?

One way is to share a single antenna and switch it between tx and rx, switching to tx when transmitting and to rx otherwise. That method precludes full duplex (simultaneous TX and RX) operation. Another way is to put additional bandpass (high Q) filtering at the receiver's front end. Another way is use as high gain and/or high Q (frequency selective) or cross-polarized antennas (one H pol, the other V pol).
 

ke5frf

New Member
One way is to share a single antenna and switch it between tx and rx, switching to tx when transmitting and to rx otherwise. That method precludes full duplex (simultaneous TX and RX) operation. Another way is to put additional bandpass (high Q) filtering at the receiver's front end. Another way is use as high gain and/or high Q (frequency selective) or cross-polarized antennas (one H pol, the other V pol).

No, sharing an antenna and switching tx and rx is half duplex. The method you just described is not simultaneous, the method the OP is describing is full duplex and is intended to be simultaneous, and requires two seperate and adequately spaced frequencies.

Using a notch filter would be another way to correct desensitization at the frequency that is causing problems.

Edit, I'm sorry, I misread your comment when you said "precludes". Dyslexia I suppose.
You are correct, it does "preclude" full duplex.
Also, I do not think the application here sounds like simple voice communication...probably wireless computer stuff if I get the OPs drift.
 
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PatM

Member
Make sure that you are operating legally in whichever country you reside in.
Some low power transmissions may be legal but most require a proper license to operate.
 

msd

New Member
To all!!
then I should put aside my efforts to make full duplex...or is it any chances to achieve this??
one was saying band pass and notch filter...can you elaborate on that...

and its not voice communication...its simple data communication...(control and feedback)
 
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