Hello all,
We have been perplexed by a discrepancy we have on a Quadrax HDSDI video line for a mission system on an aircraft. We were performing the replacement of a component and during the evolution the video line was damaged and the Quadrax contacts were ripped out. The connector is a 4 contact Quadrax connector. The connector only has 2 contacts pinned for 3 different video outputs. I initially rebuilt the connector because on one video mode the video was cutting in and out and the other two modes were completely inoperable.
After rebuilding the connector one of the video modes checked good while the other two were completely unusable with a shaky crackling display on one and a completely black screen on the other. We verified that the component was outputting all 3 video modes properly with testing cables and a monitor. We have another aircraft with the same system on it. I removed the video lwirr harness from that aircraft that the system worked on and got some strange results.
I slaved the wiring harness into the aircraft with the discrepancy on it and lost the video mode that my connector rebuild made work and instead the video feed was a very dark pasty green, the second video feed was showing what the third video feed is supposed to be and the third video feed had no output. Both wire harnesses were checked for proper wiring and all passed resistance checks.
This discrepancy is killing me!! I'm thinking there could be an impedance match issue with the connector. Because as far as I know Quadrax lines rely heavily on proper impedance matching. If anyone could enlighten me with some more in depth Quadrax theory or possible steps to take it would be greatly appreciated.
Also would the wires being slightly different lengths within the connector cause a total loss of video or miscoloring?
Thanks!!
James
We have been perplexed by a discrepancy we have on a Quadrax HDSDI video line for a mission system on an aircraft. We were performing the replacement of a component and during the evolution the video line was damaged and the Quadrax contacts were ripped out. The connector is a 4 contact Quadrax connector. The connector only has 2 contacts pinned for 3 different video outputs. I initially rebuilt the connector because on one video mode the video was cutting in and out and the other two modes were completely inoperable.
After rebuilding the connector one of the video modes checked good while the other two were completely unusable with a shaky crackling display on one and a completely black screen on the other. We verified that the component was outputting all 3 video modes properly with testing cables and a monitor. We have another aircraft with the same system on it. I removed the video lwirr harness from that aircraft that the system worked on and got some strange results.
I slaved the wiring harness into the aircraft with the discrepancy on it and lost the video mode that my connector rebuild made work and instead the video feed was a very dark pasty green, the second video feed was showing what the third video feed is supposed to be and the third video feed had no output. Both wire harnesses were checked for proper wiring and all passed resistance checks.
This discrepancy is killing me!! I'm thinking there could be an impedance match issue with the connector. Because as far as I know Quadrax lines rely heavily on proper impedance matching. If anyone could enlighten me with some more in depth Quadrax theory or possible steps to take it would be greatly appreciated.
Also would the wires being slightly different lengths within the connector cause a total loss of video or miscoloring?
Thanks!!
James
