[< 0.01 ms] I have two systems of these Spark transmiter /reciever set, they work great, the only thing that I would like to change is the battery life...it is to short, to go through a complete streaming event.
To fix this I purchased a power bank and I connect it to the usb port in the transmiter...it works very well.

[7 to 18 VDC] It seems too small and too easy to work but it works really well. I have it working on a Sony FS7 and it's great. Just to be able to transmit video is impressive, but the additional features the app includes like false color, zebras, different aspect markers, and the ability to record on your phone push it over the top. Awesome device. Get a D-tap to USB-C 5v cable too so you don't need to power it with a bulky battery. The only minor issue is the hot shoe connector fits too loosely to really be trusted. Otherwise, get this.

[HDMI: 2-Channel] This will power the Teradek Bolt 500 LT 3G-SDI Wireless Transmitter with a Panasonic battery. Works as expected.
Only thing is how expensive it is for something that probably cost about $10 to make.

[< 0.01 ms] Purchased last week, used on set last weekend.

TLDR: Love, love, love it. Tickled pink. Had Director, 1st AD, Sound (keep the boom out of shot!), and ready room all hooked to video on their phones, and at this price point!

Pros:
- Filming is a team sport: the value of letting people see what is happening in camera (clients, artistic collaborators, helpers, etc.) can NOT be understated  
- options, options, options... USB or Battery power, USB power pass through, mounting (flash/screw)
- ease of access by anyone with a phone, a tablet, or a laptop running Mac silicon
- light weight, can mount on top of camera for use with a gimbal (and power through some gimbals via usb)
- price point: I shoot with a non-profit that helps people tell their stories through film, so price is important to consider, and this is a great value at the price point!

Cons (minor gripes, but no deal breakers in my opinion)
- Plastic body has a little flex in spots
- Light weight = not a lot of heat sink (unit got a little warm, but not intolerable)
- You might hesitate to use for pulling focus (60ms lag might be a little to long for quick action, but might do in a pinch for rack focus shots)

[40 MHz] I love this set of Transiers. Very easy to setup and run. In fact, no setup is required! Pairing is almost instantaneous. They do get hot during use and the internal fan is quite.

[6 W] The Teradek Ace 750 worked perfectly. I had it shipped to an event we were working at. I was anxious to try it out and had it ready to go quickly. Another review said I should update the Firmware first but I wanted to try it out. As soon as both units were powered-on the two Teradeks were connected! I was actually amazed, I didn’t have to pair anything. Like my old units (another brand). It is supposed to be “line of sight” connectivity, so we tested it. We were in a large hotel ballroom, the guy with the gimbal and Teradek transmitter walked outside into the corridor, it was about 40-ft before it finally lost the signal. Pretty impressive. All-in-all I highly recommend the Teradek. Side note… I also purchased the L-Bracket Battery Adapter Plate for Sony NPF batteries!

[< 0.01 ms] Officially Teradek says there is less that 1 millisecond of delay but I couldn't see any delay with my eyes. This is a big step up from other wireless kits from folks like Hollyland that claim .08 seconds but in reality it's more than like twice that. This really doesn't have any latency. The feed is so instant that you can pull focus with the Spark 4k. Even though they don't exactly bill this as a system to pull focus. They seem to be pushing this as more of a live stream or event solution. However wireless video systems designed specifically to pull focus are so incredibly expensive but I'm happy to say you can use this in your regular video production shoots to pull focus without issue.



The other big selling point for me was the quality of the actual video stream you get. You can get up to 4k 30fps 10bit 4.2.2 in the actual stream. Again, this is a big step up from most system that only offer 1080p 60fps max with video quality that is just terrible.


I am not a wireless video guru so the fact that these were so incredibly easy to get up and running sealed the deal for me. Literally just turned on both units and they automatically synced up. No extra button presses to get things running. Nothing to really setup in any menus. Just turn them one, briefly wait and your video signal is flowing.

[6 W] Works as described so far with no noticeable lag between spark 4k transmitter/receiver camera and the other SDI camera.

[2.035 lb] I tried the Hollyland Mars 4K units and they were decent. However, we do a lot a band shots in our production and the delay was noticeable. I wasn't happy with that.


These units have no delay at all on our screens and have been very pleased so far.


They do get hot but that didn't affect performance. Having our camera operator be able to go anywhere in our event tent without wires gave us a great advantage with the shots we were able to get.


Best part, NO WIRES!


Charles
PTP MEDIA

[19 dBm] It is a perfect item. Easy to use. Built in battery long life