Reddit mentions of BlastCase 4xAA Battery Holder to DC Barrel Jack Connector for Arduino(pack of 2)

Very cheap option: If you already have a BMDVA then you could use a consumer HDMI home transmitter depending on your room distance.

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So your signal flow would go: Source->Cheap (maybe monoprice) SDI to HDMI converter -> HDMI Wireless transmitter -> HDMI Wireless Receiver -> HDMI cable from receiver into BMDVA.

Example: https://www.amazon.com/J-Tech-Digital-Wireless-Supporting-Transmission/dp/B071VCK1FG/ref=sr_1_3?keywords=hdmi+wireless+transmitter+and+receiver&qid=1549747552&s=gateway&sr=8-3

To power the receiver in a wireless way you'll need power on the go. This provides 5v with the standard 5.5mm plug. Never put more than the rated amount of voltage into a device, or else white smoke magic will happen.https://www.amazon.com/Generic-Battery-Holder-Connector-Arduino/dp/B00O5AZI12/ref=sr_1_11?keywords=5v+5.5+battery&qid=1549747721&s=gateway&sr=8-11

Laggy option on the cheap: If you have a macbook get a BMD SDI Recorder : https://www.blackmagicdesign.com/products/ultrastudio, shove it into the macbook and OBS, and private stream over platform of your choice (Youtube/Twitch etc) and monitor with the Ipad wirelessy (as long as you have a house wifi network, or your own of course).Windows option: Elgato H60 is a piece of trash but does work.. most of the time. This option total would be around or less than $200. Hope that helps!