Review of FPV-Japan DVR

[FPV-JAPAN]

Ok wow ! Thanks for such a detail response. That`s much appreciated.

Ill have a look, one thing Im sure its not is cable lengths. The maximum length of any one cable is one leg of a tripod





Runs to the DVR from the spitter is about 5", same going from DVR out to monitor

Thanks again Ren

ouch! I could have sworn it was long cable runs...

The only other thing that could cause this apart from cascading is just a device that does not have an input/output impedance of close to 75ohms (could be a capacitor is faulty adding impedance). Or a device has some kind of AGC (automatic gain control - this includes our DVR - that doesn't like your signals).

Either way the brighter the video image the hotter the white level. This equates to more current flowing (all be it very small signal levels) which in a poorly matched signal path could push the H-sync pulse's ground up above 0v (thereby creating a more difficult to detect pulse - hence the tearing). An AGC circuit fed with overly hot video (super white) could attempt to reduce the levels on the fly thereby reducing the level of the sync pulse on those lines that contain hot levels.

Please excuse the amount of tech detail here - the reason I am up to date on video signal levels and video in general is because I am working on a video signal generator for a future product.
I have sync/black/white/63.555uS/64uS/525/625/odd fields/even fields rattling around in the brain cell at the moment and have learned a great deal about the topic literally in the last few weeks.

Please do keep me posted on how you fair Ian

thanks,

Ren
FPV-Japan

[Coyote]

Thanks Ren, will do

[FPV-JAPAN]

A quick update on the plastic slide switches.

All requests for a replacement that I am aware of have been shipped. Please excuse the recycled or rough and ready envelopes - very well padded but I didn't have time to get out and get something of suitable size.

So far it's been only a handful and not an epidemic so I'm guessing it was a heavy handed or hurried factory worker.
But just to be safe we have made sure that quality plastic is being used.

Best regards,

Ren
FPV-Japan

[Coyote]

Ok update, I replaced on of my video wires, this improved the battery powered picture so it was fine. Then I replaced the 5v supply with a LM7805 instead and it seems to have sorted it out

Only tested indoors, but its looking promising, the diagonal lines / patterns have gone now so fingers crossed

Oh, the other day while I was flying, I went out of LOS, the DVR stopped, it froze on the static picture and wouldnt respond to and buttons or remote ?

[Charlienofun]

Oh, the other day while I was flying, I went out of LOS, the DVR stopped, it froze on the static picture and wouldnt respond to and buttons or remote ?

Hey Coyote, thats not unique to you. I have reported this quite a while back and I think some users in this thread mentioned it as well.

I find that really really frustrating. I have had it happen while airborne due to flying over the null point of the stock 5.8Ghz antenna's before I switched to CP. Now it only happens when I power down the plane before stopping the recorder but I would be really really upset if it happens when I get in a bad situation where the signal loss is due to a fly off or something. I think the only reason its not an issue for me currently is because I don't fly out of range. Still not very confidence inspiring if my video signal drops and it freezes then I go down beyond LOS it basically defeats the purpose of recording my ground feed. I mean I have cameras onboard that record at high quality the DVR is just for me to have a log of what happened in the event I lose the plane etc.

Ren any updates on this? I know we exchanged a few emails but you hadn't been able to repeat it. I'm using fox tech (sky-RF) 5.8Ghz gear (international frequency set not the usa specific one).

Anyway Coyote the only way I can get it working again after it locks up like that is by removing the battery. The file won't "close" properly if you have to do that (no way around this I have found so far) but VLC will play it back and you can transcode it back to a valid file that can be used in editors etc.

Hopefully this gets addressed with a firmware update. If not I hope someone leaks the source code and keychain so we could just come up with our own software.

[imagebuff]

Hey Coyote, thats not unique to you. I have reported this quite a while back and I think some users in this thread mentioned it as well.

I find that really really frustrating. I have had it happen while airborne due to flying over the null point of the stock 5.8Ghz antenna's before I switched to CP. Now it only happens when I power down the plane before stopping the recorder but I would be really really upset if it happens when I get in a bad situation where the signal loss is due to a fly off or something. I think the only reason its not an issue for me currently is because I don't fly out of range. Still not very confidence inspiring if my video signal drops and it freezes then I go down beyond LOS it basically defeats the purpose of recording my ground feed. I mean I have cameras onboard that record at high quality the DVR is just for me to have a log of what happened in the event I lose the plane etc.

Ren any updates on this? I know we exchanged a few emails but you hadn't been able to repeat it. I'm using fox tech (sky-RF) 5.8Ghz gear (international frequency set not the usa specific one).

Anyway Coyote the only way I can get it working again after it locks up like that is by removing the battery. The file won't "close" properly if you have to do that (no way around this I have found so far) but VLC will play it back and you can transcode it back to a valid file that can be used in editors etc.

Hopefully this gets addressed with a firmware update. If not I hope someone leaks the source code and keychain so we could just come up with our own software.

+1

Mine locked up twice in one flying session requiring battery removal both times. On at least one freeze the timer read 29:xx minutes at the point of the freeze. My settings are set to limit a single file to 30 mins.

Thanks
Chris

[Coyote]

Yeah only taking the battery out resolves the situation for me too. Its only happened the once, when it lost the video link, but yes it need addressing

[FPV-JAPAN]

Hi guys,

As regards the freeze issue. It's been covered in detail although maybe not in the form of a fix announcement but basically rather than release a different firmware the fix is to select medium quality if you find your rig is prone to causing this.
I have experienced it once myself and after a lot of attempts at trying to reproduce it at the factory we came to the conclusion that the most likely cause is the high quality (low compression rate) which is pushing the codec to it's limit.

Sometimes my DVR will freeze while recording. What is the cause and what can I do to avoid it?
While this has only been reported by a few customers we have spent a while looking into this issue. Its been damn hard to reproduce on demand but one or two customers have been able to reproduce it at least once or twice and it invariably happens when the TX is turned off after a flight.
Several factors can contribute to this issue. A high data rate coupled with a receiver that has a large bandwidth which is then subject to video noise (no signal). And as mentioned above, a TX turned off while still recording would appear to be the most likely trigger for this to happen.
This is no real fault of the DVR (or certain receivers), rather we have chosen to go for good image quality by using an exceptionally high data rate (that admittedly might be just a bit too high for some receivers).
If this has not happened with your setup then there is nothing to worry about. However if you have experienced a freeze then the issue can be avoided by stopping recording before turning off your transmitter. If the issue happens at any other time, you might want to try changing the quality setting to medium.

I've cleared up my PM folder so that method of communication is open again.

thanks,

Ren
FPV-Japan

[imagebuff]

Hi guys,

As regards the freeze issue. It's been covered in detail although maybe not in the form of a fix announcement but basically rather than release a different firmware the fix is to select medium quality if you find your rig is prone to causing this.
I have experienced it once myself and after a lot of attempts at trying to reproduce it at the factory we came to the conclusion that the most likely cause is the high quality (low compression rate) which is pushing the codec to it's limit.


I've cleared up my PM folder so that method of communication is open again.

thanks,

Ren
FPV-Japan

It sounds like high shouldn't be quite that high if it is prone to failure. Why not tweak the high setting very slightly lower in the firmware so it actually functions properly? A ground based recording unit should be reliable at any factory setting.

This sounds like " Hey Doc it hurts when I move my arm like this ..." Doc says " Well then don't move your arm like that".

[FPV-JAPAN]

Hi imagebuff,

There have only been a handful of reported instances as opposed to an outright epidemic and it is something that can be prevented easily otherwise I would have pushed relentlessly for a fix.
If we get some down time I may push the factory to work on a new firmware release but for now the fix is to use medium compression.

edit: I should clarify - if and when I get the time to twist another arm at the factory there will be a fix in firmware - I for one certainly would like to be able to record in the highest quality possible. But unfortunately for now the fix is medium quality.

thanks for your understanding,

Ren
FPV-Japan