shumifan50
- Jan 16, 2014
- 579
- Joined
- Jan 16, 2014
- Messages
- 579
I have a video cable from a micro camera to a 5.8GHz transmitter. The 2 units are very close together, about 5cm cable length.
1. Do I need to use screened cable or will I get away with unscreened wire?
2. If it has to be screened, do I connect the screening on both modules or only on the one side. The units share a common ground, so I was wondering about ground loops.
The reason for the question is that I get interference on the received picture. I have played with different styles of antenna, following various recommendations(I have another thread on this forum). The units are close together at the moment while I am testing, so the antennas don't seem to make a difference, which is why I suspect the problem is elsewhere. I have tried an Immersion 5.8Ghz rubber ducky antenna and it also made no difference (used a prewired SMA connector).
If I eliminate the transmitter/receiver and connect the camera directly to the monitor, the picture is perfect. However to do this I have to use a specialised cable. I have traced the cable with a multimeter and think I have made identical connections for my cable to connect to the transmitter, but something is off.
Next thing I am looking at is the power supply. It is a polulu adjustable output step up/step down SMPS power supply. Supply is a LiPo single cell. Output is adjusted to 3V (should be 3.3V but the transmitter gets VERY hot at 3.3V and in close proximity testing it seems to make no difference at 3V but runs much cooler). They recommend a 33uF cap over the input, which I am waiting for (tantalum 33uF 16V to keep it small and light). Could the power supply itself be the cause of the interference as it has no screening around it. although at the moment I keep it about 30cm away from the transmitter. It will be about 1cm away in the final installation.
1. Do I need to use screened cable or will I get away with unscreened wire?
2. If it has to be screened, do I connect the screening on both modules or only on the one side. The units share a common ground, so I was wondering about ground loops.
The reason for the question is that I get interference on the received picture. I have played with different styles of antenna, following various recommendations(I have another thread on this forum). The units are close together at the moment while I am testing, so the antennas don't seem to make a difference, which is why I suspect the problem is elsewhere. I have tried an Immersion 5.8Ghz rubber ducky antenna and it also made no difference (used a prewired SMA connector).
If I eliminate the transmitter/receiver and connect the camera directly to the monitor, the picture is perfect. However to do this I have to use a specialised cable. I have traced the cable with a multimeter and think I have made identical connections for my cable to connect to the transmitter, but something is off.
Next thing I am looking at is the power supply. It is a polulu adjustable output step up/step down SMPS power supply. Supply is a LiPo single cell. Output is adjusted to 3V (should be 3.3V but the transmitter gets VERY hot at 3.3V and in close proximity testing it seems to make no difference at 3V but runs much cooler). They recommend a 33uF cap over the input, which I am waiting for (tantalum 33uF 16V to keep it small and light). Could the power supply itself be the cause of the interference as it has no screening around it. although at the moment I keep it about 30cm away from the transmitter. It will be about 1cm away in the final installation.
