# Power Over Tether Fathom X

**URL:** <https://discuss.bluerobotics.com/t/power-over-tether-fathom-x/2767>\
**Category:** Communication Interfaces\
**Tags:** fathom-x\
**Created:** [June 7, 2018, 8:03pm UTC](https://discuss.bluerobotics.com/t/power-over-tether-fathom-x/2767 "2018-06-07T20:03:27Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![CarlosG](https://avatars.discourse-cdn.com/v4/letter/c/ecccb3/32.png) [@CarlosG](https://discuss.bluerobotics.com/u/CarlosG)\
**Post date:** [June 7, 2018, 8:03pm UTC](https://discuss.bluerobotics.com/t/power-over-tether-fathom-x/2767/1 "2018-06-07T20:03:27Z")

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Hello, I’m working with a quadrotor powered over tether, I’m using almost 400 VDC from a ground station, on the vehicle I use a step-down converter. I want to transfer video from the quad, so my question is, can the fathom X work with 400 VDC?

Thanks in advance.

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**Author:** ![jwalser](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/jwalser/32/2234_2.png) [@jwalser](https://discuss.bluerobotics.com/u/jwalser)\
**Post date:** [June 11, 2018, 7:05pm UTC](https://discuss.bluerobotics.com/t/power-over-tether-fathom-x/2767/2 "2018-06-11T19:05:13Z")

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It is designed to handle 400V, and some customers have had success with this. We do not support this type of use though.

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**Author:** ![arikarbel](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@arikarbel](https://discuss.bluerobotics.com/u/arikarbel)\
**Post date:** [July 19, 2019, 12:55pm UTC](https://discuss.bluerobotics.com/t/power-over-tether-fathom-x/2767/3 "2019-07-19T12:55:46Z")

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Hi Carlos,

Did you end up using the fathom-x on your system?  
Does it work ok?

Tnx.

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**Author:** ![BlueLink\_PS](https://avatars.discourse-cdn.com/v4/letter/b/838e76/32.png) [@BlueLink\_PS](https://discuss.bluerobotics.com/u/BlueLink_PS)\
**Post date:** [July 20, 2019, 6:18pm UTC](https://discuss.bluerobotics.com/t/power-over-tether-fathom-x/2767/4 "2019-07-20T18:18:27Z")

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Hello Arikarbel. I have bench tested at 350VDC (albeit with a slightly different PCB for the LX200V20) and it worked fine. I have yet to test in the water but don’t anticipate significant issues. Depending what your input filter at your step-down regulator looks like, it may be necessary to alter your input impedance. I used a 68uH/10A inductor (in parallel with a 47Ohm resistor) in series between my data connection and the input of the 500W power supply. It worked fine on the bench, but was only a test with 30m of tether. Power wires were untwisted 22AWG, voltage was just over 350. however, I use a tether with 2 twisted pairs + power, so I haven’t really needed to run this option. I am now experimenting with running the FathomX (with added zero-cross circuity) over 240VAC. I’ll post once we have some good field data. Please let us all know how your setup goes.