Video System Wiring - Help?

[qb7ops]

Hi all,

I picked up a Tx, Rx, and small CCD camera without any wires or cables; price was right. Now I need some advise on wiring the video system. Specifically, what kind of wire or cable and connectors should I use, and where specifically I can buy such supplies? So....type and gauge power wire from the battery to the transmitter and camera. Also, what kind of cable is required from camera to transmitter for video. I have attached a wiring diagram of what I plan if that will help, and a pic my tx and cam minus the battery and two DE regulators. Just to let you know, I did have it wired up at one point using just 18awg speaker wire to test. It does work, but with a lot of interference.

I did a search and found a coax cable that might work well. Take a look when you get the chance http://bwccat.belden.com/ecat/pdf/179DT.pdf. The cable has an nominal diameter of .1" (2.54mm) and is shielded. States it is suitable for digital video. I would think that both the power cables and video cable would have to consist of some sort of shielding from EMI and other types of interference. As shown in the pic, I have the wire that connects into the cam, but would like to replace that as it is old and does not look to very efficient.

Before I install this on my Logo10, I will play around with it on my TrexSE, so I am trying to keep the cabling as light a possible without compromising integrity of video signal. Basically, I will be mounting cam on a small gimbal on the front of the Trex. The av sys batt will be up front as well as the av tx.

So apart from what type/gauge cabling, would anyone also have any specific online sources?

[catfight]

qb7ops,


I don't know what you have available where you are, but, you could use the video cable from a normal dvd (or vcr) to tv connector set (the one with yellow,red,and white with RCA connectors on each end). Strip off the yellow wire (video rated and sheilded) and cut off the connectors. Wire the shield wire on both the tx and camera video out as close to each end to the black solder connection- make this direct - not thru some other ground connection. Then take the center conductor and solder to the video out on the camera and video in on the tx. It should be relatively easy. Make the unsheilded center wires as short as you can. Of course make sure you support conenections with something so they don't get broken :)

Does that help?

[qb7ops]

Thanks Rusty, that did help. I previously checked the PX we have at our location and they do carry an assortment of dvd/vcr and s-cables. What you describe was going to be my alternative if I did not come up with high quality application specific cabling. So I am glad you brought this up. I will buy an already built system at some point as well, but prefer this route for now to help me better understand what makes it all tick. So I don't mind investing the time and money for materials that will best work.

A couple of more questions for you.

1. Are there any application specific connectors you would suggest using? Or, is it better to solder directly to the tx and camera lead?

2. What would you suggest as the minimum guage for the power and ground wires?

3. Is it worth using shielded shrink wrap for soldered locations, or will regular wrap suffice? I found the EMC ShrinkMate which looks good: http://cableorganizer.com/heat-shrink/conductive-heat-shrink.htm.

4. Lastly, should I wrap the tx in some sort of shielding? I have heard some people wwrap plain tin-foil around it, but I think a large diameter of the ShrinkMat would work.

Thanks again Rusty; appreciate your input. By the way, I found out the tx is a Videocomm 2.4Ghz 800mW and cam is a Panasonic CX-151. Both are suppose to be fairly decent.

Lachlan

[catfight]

qb7ops,

1. Unless you plan to plug/unplug the video signal conenction I would say soldering close is better than adding connectors (if the board had been made with connector pads it would be better with connectors).

2. You don't really have to worry about tx feedback too much in the power system- 2.4 ghz does not affect it. This camera and tx draws less than 1/2 amp so wire 24 ga (22 ga also) provides at least 10x over standard current loading and above and would be sufficient.

3/4. I would experiment after installing the video shielded cable (video level signal is most susceptible to noise pickup). I have never used this shrink shielding except on ghz rated radio connectors so have no experience. I don't think I would shield the tx with it because of possible heat build-up issues. The tx is 9 volts at .5 amps which totals about 4 watts or more. Good short grounding systems between the different components will prevent a lot of "ground loop" pickup. Keep wires short wherever you can.

[qb7ops]

Rusty....u da man! Thank you very much for your help on this. Once I get it all hooked up and working I will send you some pics for your critique. I have quite an interesting front mount gimbal you will get a kick out of.

Thanks again - Lachlan