NRF24L01+ Longer wires or add antenna cable?

I am using a network of simple 2.4 ghz Nordic NRF24L01 radios (with the stubby SMA antennas) together with pro mini Arduinos. I have to place one radio and sensor inside a metal tube about 6 to 9 inches from the end. I want the antenna to be as close to the end of the tube as possible in order that it stays in range of its base unit.

Am I better having longer wires connecting the pro mini to the nrf24, or am I better off using a small piece of antenna cable?

I ask this question because I do not want to risk diminishing radio signal. i.e.

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Arduino================Nrf24+Antenna ))) ) )
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Or

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Arduino+Nrf24================Antenna ))) ) )
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What would you do, does such a short distance make any difference?