The RedPitaya inputs are 1MOhm terminated. Do we need a 50Ohm feedthrough terminator?

[M4a1x]

At 25MHz I would expect some reflection of the signal at the Red Pitaya when connecting the 50Ohm cables to the 1MOhm Inputs. Do we need a 50 Ohm feedthrough termination (e.g. T4119)?

Wavelength at 25MHz in air: $\lambda = c/f = 12\textrm{m}$ Wavelength at 25MHz in PE (i.e. coax wire) ($\mu_r=1.0, \epsilon_r=2.25)$: $\lambda = \frac{c_0}{f\sqrt{\epsilon_r\mu_r}} = 8\textrm{m}$ So $\lambda/4 = 2\textrm{m}$, which is getting relatively close to our cable length.

[M4a1x]

The inputs and outputs of our specific RedPitaya actually are BOTH 50 Ohm terminated. The feedthrough termination is only necessary on the other end, e.g. the oscilloscope.