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It's unfortunately one of those manufacturers who happily says "Firmware upgradeable" in the feature list, but who never ever released an upgrade, it's even impossible to find a copy of the original one... <_<

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Okay, getting paranoid now! I thought I'd nailed this problem:

Mobibox clone PVR has ?faulty firmware that sets the ?White balance too high - Result: video recorded from composite IN is too bright, and washed -out.

Solution: Although AGC tries to correct at first, increasing attenuation of the composite IN (with a simple 100 ohm pot) eventually cuts down brightness.

However, I have been using the Oracle diversity switcher. Recording to miniDV is fine, but as distance increases (so neither signal is particularly good) the picture on the Mobibox 'wobbles' for a second or so after switching. I presumed this worse performance was due to the signal amplitude being so much smaller post-attenuator for the Mobibox, so it struggles to re-establish sync (turn the attenuator up, and the picture is washed-out again, but the post-switch wobble stops).

Anyway, in search of a better PVR, I came across a cheap Rollei ea2020g - Rollei a reputable firm, surely they wouldn't skimp on the video input setup? But once again, the video is washed-out :o ... They're following me... :(

Again, I can counteract this with an attenuator, but surely one PVR having trouble = PVR, two having trouble causes me to wonder again if there is a problem further up the line. Okay, my miniDV camera is OK, but it will have a different AGC etc.

So, any more suggestions? Would it make more sense to adjust the amplitude at the transmitter (the diddy trimmer on the diddy RC Tech transmitter boards) than at the receiver end? Is there any way of leaving the amplitude of the sync pulse alone, while attenuating the amplitude of the luminence part of the signal?

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No single change if changing the level on the TX - the result will be the same or worse as less of the dynamic range of the TX will be used...

Terry's solution might be good indeed, but pricey... and we can only hope the correction range it offers will be enough. Not really worth the bucks if it's to be used on a cheap recorder anyway IMO... better directly get a good recorder.

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Terry - thanks, I knew there had to be something like this out there... a means of "pre-post-processing"!

Kilrah - well, on paper the Rollei _was_ a good recorder! Higher bit rate than usual (3MB/s), DivX.

For some reason I'm obsessed with finding a small hard disk/flash pvr that records miniDV format. MiniDV looks just so much nicer than these non-interlaced formats, and after all, an hour of miniDV is "only" 10GB. The video equivalent of those higher-end MP3 players that will also record & playback .WAVs.

I'm slightly antagonised by miniDV cams since, over the years, I've become convinced that my miniDV tapes wait for something exciting to happen so they can run out just beforehand...

... oops, more paranoia...

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There's no DV recorder that will record to flash drives that I know of. Maybe in the professional market, but then you could expect a price tag you could buy 3 DV camcorders with...

There was some company that had said they were making an embedded full-resolution, high-bitrate MPEG-2 recorder. Not as good as DV, and even that was more than 1 year ago and I haven't heard from them anymore.

You can go for DV. There's a substantial number of new miniDV-based devices that still get released now, and even in the professional market.

There's pretty much no new format that offers the same flexibility/quality ratio out there yet, so it still has some years to live.

And then even once it's obsolete: remember Digital8? That was replaced by DV 10 years ago, and you can still find tapes everywhere. I've even been at places where it was actually easier to find those than DV ones...

Your camcorder will be dead/replaced by some new high-definition thing WAY before you won't find tapes anymore.

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I just thought I had better add that you can get that gadget cheaper if you shop around. It's good for converting old tapes too :)

Terry

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The CTB 100 seems to achieve its ends by digitising each frame, adjusting the picture, then re-constructing the analogue signal - brute force! And of course this is the only way to do it across so many video standards. But it therefore clearly is possible to adjust brightness independently of the other parameters (chrominance, sync amplitude etc.).

I'm left still wondering if there is a simpler piece of circuitry that can do this, for the brightness.

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I'm left still wondering if there is a simpler piece of circuitry that can do this, for the brightness.

The circuitry is not as easy as it seems. Have you checked eBay? Low cost consumer video processors were common years ago when folks needed to clean up bad video tape images. I suspect they are bargain auction items nowadays.

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Indeed, that's what you have in any analog TV that can adjust brightness/contrast/saturation...

But to adjust that you can't do it directly on the composite video, you first have to demux at least Y/C/Sync, apply your gain to Y only, and remux, thus the complexity of the circuitry...

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(oops, on closer examination, I see those aren't exactly the same frames! Here's the miniDV frame that matches the PVR one more closely)

I had the same problem. That is if I only connected the video goggles to the RX. However when I have connected the PVR and goggles using the "Y" splitter then It was ok. I tried the DV recorder too washed out. With Aiptek recorder it is great. I believe that Aiptek while sharing the output with the goggles made it ok for the video. Goog Luck Doofer.

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LVS, that sounds like you have a bad video level setting on the RX (way too high). By using the Y you divide the level by 2, and it happens to come back to something more sensible. If both your goggles alone and DV recorder alone show a washed out picture it's most likely the reason. Unless you like it that way and always use the Y, why not. It must still not be optimal though.

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I've come across the PMC-500R (sold as PVR 500r); Mark at Dogcamsport (!) assures me that it out-performs the Mobiboxes and Archos recorders easily, and :D:D:D has user-adjustable video recording parameters (colour, saturation & contrast) :D:D:D .

Mind you, 250 quid is not cheap in anyone's money - anyone on this list come across this player, before I assume it will put to bed all these "too light, too dark etc." problems?

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It's indeed definitely not cheap, but so far from the specs I haven't found anything that good yet.

But then, as the $ difference with a camcorder is getting low, why not put the little bit more (if any) and have the best out there while you're at it? I bet it would be a hard decision.

Edited by Kilrah

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It is difficult, especially as I can get a camcorder that records, about half the size of the one I currently use, for half that price! And most of these include adjustments of the picture too.

In my mind, the advantages of PVRs are:

- smaller

- longer battery life (sometimes)

- more rugged (miniDV is a mechanical jewel - but susceptible to dust)

- (effectively) unlimited recording time - not that my FPV flights are more than a few minutes, rather that I find tapes run out just as something interesting is happening.

- dub to PC in seconds, not minutes

- non-linear sequence access (also a boon when editing)

- can work when tucked in a rucksack pocket, rather than switching off when you close the screen

Disadvantages

- often need to first convert to miniDV format for easy editing!

- expensive (cf miniDV) hardware, it seems

- need to think about archiving (rather than just changing to a new tape)

Perhaps this is becoming a different thread!

However, my bigger uncertainties are all those other parameters of interest to FPV recording which are never in the manuals e.g.

- how does it cope with transmission breaks: does it just switch off after a second or two?

- How well does the recording codec compress sky: smooth gradation or lots of dancing contour lines?

- How well does it cope with video switches e.g. Oracle diversity switcher?

- Does it encourage or discourage 'tearing'?

- How good is the audio channel separation ie. is there much breakthrough if you record 'plane sounds on L & ground sounds on R?

At this price, I'm less likely to just get one and experiment - it would have to do okay at least on these points to make it worthwhile.

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