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Ok, Next issue. I was testing my 500mw 2.4 system today with odd results. When viewing through new 545 video glasses I'm getting a strobe effect. It's a fast flickering of the brightness thats at it's worst with a scene of both of dark and bright areas. Only parts of the view flicker. This is with a 131kx, Lawmate 2.4 500mw TX, lawmate receiver and the glasses.

My troubleshooting results:

Replaced googles with both a lcd, and crt and it did NOT strobe.

If I replace the camera with a DVD feed, the tx / rx / glasses do NOT strobe.

If I hook the camera directly to the glasses there is NO strobe???????

Used a video spliter/ amp, and adjusted levels with no improvment.

It's the combo of all 4 items in the chain. I'm very fustrated after a long day with bad results from my efforts! I can't pin the problem to any one part of the system. Any thoughts on this one? I have hit a wall!

Edited by wmacky1
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I do!

I too get some minor strobe lines on my Rvision specs, which are probably a similar chipset to the 545. It's mildly irritating, not as bad as wmacky's problem, but only there on the RF link.

What do you suggest we look for?

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This is hard to judge without a look at the signal's waveform. You could try the following instead:

1) Place the camera in a dark room or just put its lid over the lens to cover it and see if the the strobe effect still occurs.

In comparison to that vary the amount of exposure up to bright day daylight and see if there are any changes in the amount of strobes.

2) However you might like to try another camera with your TX/RX setup as well, for example the AV-out of a camcorder.

3) Put the video amp/splitter in series between the camera and the transmitter and play around with the levels. If this helps a next step could be to adjust video level sensitivity on the lawmate.

But again, I would definitely try to get access to an oscilloscope, maybe there is a friendly TV-service near your place where you could ask if you could bring your setup to have a look at the waveform. It takes about 10 minutes, so it should be not too much trouble.



Edited by Hartwig
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Still not sure what I'd look for on the waveform - especially when the composite video waveform is so complex!

However, I've got a 2-channel scope, so when I have time I'll compare 'Direct' with 'By downlink' signals, and see if there is anything obvious.

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Hi Doofer, the syncs need to be in "good shape" and the video levels must be correct, that means from 0V to 1V absolut range, not more, not less. (a little overhead of up to 0.2V might be tolerated by most devices, but that is not a "Must". However there must not be a DC offset, and the video level of black must not be lower than 0.3V! Otherwise it will screw up your syncs.)

You might like to take a look at this page for a simple example of the video waveform (vid_wf.jpg) :


As a real life example, I attached a pic that shows the waveform of a black screen with a light grey vertical bar in the middle of the picture. (Timebase 10us/DIV).


Edited by Hartwig
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I'll try to record waht I am seeing in the glasses soon. I tried again and I'll try to describe better what I see. There are no lines or static, but rather a clear picture, and the dark areas of the view seem to rapidly pulse in brightness. The brighter areas seem to be fine. in other words, the whole view does not pulse? only parts of the image.

Example: If doing the test with the camera inside the house and pointed outside towards a window, the view throught the window would be ok and the darker part around the window pulses.

Thoughts: Replace anyone of the 3 parts ( googles, camera, or Monitor) and everything is great.

I'm using the most popular stuff, and no one else has reported the issue, therefore it should not be a compatability issue?

It will be much cheaper to start eliminating parts rather than buy a scope. Which part would you replace first, TX. RX, Googles, Camera? As noted they all work fine with just one part eliminated?

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  • 2 weeks later...

How are you supplying power to the system you are using? What kind of vreg and capacitors do you have on this system?

This may also be a problem caused by not enough juice on the vreg. Is the vreg hot when you are transmitting?

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I have a set of cy-visor goggles, with the stock default settings, I get a lot of flicker, if I go through all the menues, there is a flicker setting which removes the effect. There is an adjustment for left and right sides. Not sure why, but the stock settings are pretty bad, color is off too. Once I did some adjusting, they look much better.

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