Avatar HD Digital FPV VTX - Power & Thermals Deep Dive

[@Tokyo_Dom]

Interesting stuff, I had assumed it was the SOC that needs the most cooling, and it seems that's how Caddx intended it too since the mipi is on that side, and the wires to the fc are on the PA side (shortest route to camera/fc has the SOC facing up). Well, so far no overheating, I have airflow anyway

[@sullytrny]

Thanks as always, for me on an M7 elrs prebuilt it hit 90c 45 seconds after goggle binding with a flashing temperature warning. After binding the radio it seems to stay cool enough long enough to get airborne. My only regret is the first video is of my messy kitchen. I've got the full size also for a friend's build and this being my only HD experience I can't imagine a better view

[@lemonsquareFPV]

Thank you Ian! Great overview! Can we do the Whoop lite (maybe even Race V2) next, that’s the other board I have mostly been beating on other than the Avatar stuff… haven’t been able to break any of them yet. Have been very pleased!

[@MCsCreations]

Thanks for testing, Ian! Fantastic info!!! 😃 Stay safe there with your family! 🖖😊

[@BowserMG]

Very interesting video. Great content Ian, looking forward to more videos like this.

[@GeorgeCee]

With spacers giving Air flow above & below this VTX for ventilation, what side should be facing up for ideal heat dissipation?

[@johncgibson4720]

Great info. I im curious if you can remove the heat sink to save weight. If that can save 7 grams or more, I will order it now.

[@RobotZhUntER]

I have 2 Ufl that in flight fails I believe due heat fatigue, I have a photo from my microscope, and you can see burning areas in the plastic side of the connector

[@MadRC]

I’m not shocked it gets to 90+

[@WATCHMAKUH]

Speaking of thermals….I stumbled upon this upcoming camera…foxeer ft640 thermal analog cvbs camera. The smallest 640x512 pixel thermal FPV camera! Simple hookup to standard VTx. It’s $3,500+ (probably a lot of markup just to make it worth while on not many units being produced I’m assuming). Thermal imaging on an fpv would be a great step into surveillance and surveying. I hope you can convince Foxeer into reviewing this camera!

[@nmrlab3807]

Very nice, can I use softserial instead of UART for the VTX? I have no UART left on my FC. I have F411-WTE, and been using its two UARTs for the ELRS and GPS connections. Thanks

[@narr0wm1nd49]

Great work Mads. I had a question if mounting the VTX in a PLA printed part was going to be a problem. While the VTX does get hot it seems the thermal shutdown kicks in well before it should be a problem for PLA.

[@jorgeneo560]

i was using analog 5.8 ghz on a fpv plane and had to use a minicooler, i had switched to walksnail and for what i see the cooler will remain on the plane

[@Vorname_Nachnahme]

Is it possible to replace the stock heatsink with a bigger, more powerful one? (no flight application)

[@MrAlucardDante]

Great video as always. Since a lot of fairly recent FCs have a digital plug that powers the VTX, it could have been interesting to measure the current draw at 9V too, just to make sure that the BEC can handle it

[@MadRC]

9v will be 900mah.

[@MrAlucardDante]

@@MadRC thanks

[@Simofly]

Very interesting ! So it’s better to mount the vtx even the Full one , with the soc and pa facing up have I understand it right ? Do you have any insights or feeling that caddx will release a new V2 full VTX version soon ?

[@fpvskills]

Great Channel Bro

[@McLogo76]

great interesting vid! The 1s VTX is 350mw max as far as I know?

[@MadRC]

Yea sorry I was thinking of the HDZero

[@CXBFPV]

​@@MadRCso in your test you were at 350mw for the 1S VTX? Do you think a 5V 1A BEC from an AIO would be ok? I'm planning on putting this in a Happymodel Larva X which runs on 3S but has a 5V 1A BEC.

[@salukikev]

I think the scenario where current draw most comes into play is when folks want to run minimal hardware on their cinewhoops at 2-6s, this means you'd likely hope to power via 5v BEC, and a lot of times they are rated to 1A- not sure what sort of margin they might have.... 1.1A is a pretty tempting spec. to try it. I wonder if heat & assorted video modes would cause a higher current draw.

[@Vousie]

Just remember that sometimes there are other things on the 5v BEC as well, so just make sure the total isn't over its rating.

[@craigreynolds4449]

I found the full size vtx overheats in standby mode. can you shed some light on why you think it overheats in standby please?

[@larrys8645]

Great thermal info. I have noticed that my Micro VTX , when in standby mode , issues a temperature warning after some period of time. Could you investigate how long it takes to issue the warning from a cold staart in standby mode? Thinking this would be useful to know prior to take-off waiting for GPS lock. Thanks.

[@sivisjoe9877]

You can turn off the goggles and the vtx will go into a lower power state

[@sivisjoe9877]

use telemetry to view gps

[@visioneerone]

for the first flight of the day I power up the fc, rx and gps of my quads with a usb power pack. I monitor the satellite status on my transmitter. Once I have a lock I plug in the main battery and go fly. No overheating!

[@williamwebster2490]

How did you delid the CPU? I was planning on putting an aftermarket heatsink on it, and that would actually help the two chips be level

[@MadRC]

A fine blade around the sides, there is some soft adhesive.

[@williamwebster2490]

@@MadRC Have you tried doing your own cooling solution?

[@Camilookb]

The fact that the heat sink doesn't get warm makes me question how effective that heat sink is...

[@Vorname_Nachnahme]

Someone probably forgot the thermal compound between the chips and the sink ... Oo

[@willwill5539]

Or it's really good.

[@marc_frank]

love the DMM

[@MadRC]

We all love Dave ;).

[@arvidbjorkstrom6554]

A comparison to DJI and HDZero would put this in perspective. This video makes it sound like having a hotter heated part than heat sink is a non standard outcome and to me that sounds like standard thermodynamics? Sure, thermal conductivity of fiberglass is worse than aluminium, but the copper traces on top of the pcb are more thermally conductive than aluminium. And have much less mass. The silver screen is probably a little bit insulating, maybe making the or read a little less than the heat in the copper. But with a slow heating proceeds it should have time equalize.

[@ibeginge113]

In your opinion Mads how quickly would you cause damage to a V2 dual antenna VTX if powered without antennas connected?

[@MadRC]

It’s possible it would damage eventually however I would not expect it to happen instantly. Iv seen no evidence of any burning out even after some time.

[@ibeginge113]

@@MadRC thanks for the reply, in my heist to get a new V2 vtx fitted and setup i had it running for 15/20 mins on the bench with out antennas connected. appreciate the reply

[@terminsane]

I bet you could calibrate the thermal camera using a soldering iron

[@w1llyFPV]

Do you have similar video regarding Hdzero vtxes?

[@MadRC]

Coming soon.

[@w1llyFPV]

@@MadRC thanks 👍

[@terminsane]

Id like a heavier vtx with more cooling. Currently, Walksnail is for wings imo.

[@EnglishTurbines]

This is why you shouldn't stick your VTX to the carbon frame using double sided tape. Or even a tywrap. Mines on M2 hardware spaced off to give all round airflow...Bad form of Caddex to not provide long M2 bolts and nuts IMO. The US doesn't even know what M2 is...🤔😳😏😏🇬🇧

[@kozotto]

how was temperature Max at 1s avater? my one get 100℃　in 3mini.