# LimeSDR transmit and receive on the same antenna (half duplex)

**URL:** https://discourse.myriadrf.org/t/limesdr-transmit-and-receive-on-the-same-antenna-half-duplex/3390
**Category:** Uncategorized
**Created:** [27 September 2018 13:57 UTC](https://discourse.myriadrf.org/t/limesdr-transmit-and-receive-on-the-same-antenna-half-duplex/3390 "2018-09-27T13:57:36Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Lukf](https://avatars.discourse-cdn.com/v4/letter/l/a8b319/32.png) [@Lukf](https://discourse.myriadrf.org/u/Lukf)
#### Post date: [27 September 2018 13:57 UTC](https://discourse.myriadrf.org/t/limesdr-transmit-and-receive-on-the-same-antenna-half-duplex/3390/1 "2018-09-27T13:57:36Z")

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Hi,

I would like to use a single antenna for transmit and receive in a half duplex mode, but the power of the transmitter on tx1 output exceeds the maximum power that can safely be fed to any of the receiving inputs.

So my question is: do I definitely need some sort of an external RF switch (a duplexer), or can I use the input shorting switches to protect the receiver?

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### Author: ![AA7QQ](https://avatars.discourse-cdn.com/v4/letter/a/13edae/32.png) [@AA7QQ](https://discourse.myriadrf.org/u/AA7QQ)
#### Post date: [28 September 2018 00:00 UTC](https://discourse.myriadrf.org/t/limesdr-transmit-and-receive-on-the-same-antenna-half-duplex/3390/2 "2018-09-28T00:00:34Z")

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Yes, you will need a Duplexer of some sorts. It is really 2 BPFs that allow signal of different frequencies to go different paths.

Ed