Wireless Video

[FredB 0]

Doing a job where we are putting 3 cameras on a wood pole. Can not run wire to the DVR. Getting power from the pole.

 

Distance to DVR building: 200 feet.

Only a couple of trees in between.

Thinking about something like this.

 

Questions

1. Are the specs overkill or...?

2. Are using 3 cameras, so do I need to get 3 kits and set them on different channels or? Any chance of interference that way or?

3. Is there a 4 camera transmitter reciver or...?

 

Is this the best soulution?

 

 

http://www.videocommtech.com/index.php?SCREEN=view_catalogue_level4&model_ID=303#galleries

[rory 0]

These are supposed to be their best ones ..

http://www.videocommtech.com/index.php?SCREEN=view_catalogue_level2&add=edit&prod_ID=10

 

I used 1.2Ghz before and cell phones would mess up the signal, as well as other unknown occcasional interferences ..

[FredB 0]

Seems like they recommend either 900MHz or 2.4 GHz. Any thoughts about that. Guess I should just call and ask them.

A new area for me.

[DataAve 0]

You will get a lot of interference in those ranges.

[C7 in CA 0]

That's a good question. I have been looking at this equipment today. I was looking at this chart: http://www.videocommtech.com/uploaded_files/pdf_archive/Frequency_Performance_150.pdf

 

I was hoping for one receiver. Reading things like "selectable channels" makes me think it's a receiver for each channel. That makes for one ugly install on the receiver end when you need them all in one spot. But then I look at all the weather tight fittings and now I don't know what to think.

[rory 0]

the TX is inside the weatherproof box, just take them all out and make your own .. or ask them for a custom application.

[C7 in CA 0]

Good idea.

 

If they are really good I could mount them in the attic...

[rory 0]

Just watch out for heat, those things put off alot of it. The ones I had that I put in the attic, I hooked up a CPU fan from a computer, with the heat sink and all, and attached it to the TX, in a 4x4 gang box. i also drilled holes in the gang box to let out the hot air. Kept it reasonably cool since the attic was well over 150 degrees or more in the summer days down here, and even in the winter.

 

The heat wasnt the real problem why i stopped using them, it was the concrete buildings here, and AC ducts, that blocked alot of the signals and then had to run all kind of wire to get around that, and plus, the High Voltage that caused the interference, as well as cell phone interference when it rang! Also, I got the TX in the end up high, but the RX was a different story and that is where alot of my issues were. So basically if you are goign to do it, take into account that they have to go well above any objects that could block it and far away from any high voltage. It was just alot easier in the end to run wire

 

Apparently 900mhz can punch through concrete alot easier, so depends where you are installing them, The 900mhz dont have the distance of the others though.

 

Now they were not VideoComm Wireless, but from reading their info its similar in the way you have to install them.

 

I may have a large wireless job coming up actually, and could use the help of some of you DIY guys that like to "build" things ... ill post when the time comes (in the dealer section). Im talking 4 mile distances in a gated community full of million dollar homes... so would be alot of fun also ...

 

We'v e already got the job to re-do the security gate, and the cameras are here so thats happening next week ... after that then we will work on getting the rest ..all extreme CCTV IR and Wireless VideoComm 5.8Ghz.

[bryan1656 0]

FredB:

 

The 1st rule on wireless video tx is "Don't do it."

 

The 2nd rule on wireless video tx is "Ah, ah, ah... Dooon't do it."

 

The 3rd rule on wireless video tx is "I'm really not kidding. Don't do it."

 

900MHz is going to be very susceptible to RF interference and will be very vulnerable to RLOS problems.

 

These vulnerablities only increase the higher you go up the freq food chain up to 5GHz, etc.

 

Only some trees? Let me tell you, all the water in the leaves of those trees *WILL* cause problems with RLOS in those freqs.

 

The higher freqs that we see in wireless video have a hard time carying all of the information in that 1V ptp @ 75Ohm composite video signal.... even if you get good distance and good RLOS with absolutely no RF interference.. the signal is still not going to be great.

 

The only time I use wireless video tx is if I absolutely must have live monitoring of the signal and if I absolutely under no circumstances am able to run cable and if the video signal IS NOT absolutely critical. (lower freq audio back up, eyes on target, local system back up, etc.)

 

and this is just when considering ONE signal... you're wanting to run THREE ... which is sort of like installing your own RF interference in the exact same freq range that you are trying to use... PLUS you are going to need weatherproof..

 

If you absolutely MUST do wireless... then I'd recommend going with directional yagi ants on both ends - and use at least 5watt transmitters - asalready noted, these things will put of some fairly serious heat.

 

And what about signal encryption? Is this a video signal that you want braodcasting"in the clear"? Any encoding/decoding is going to add data on that already vulnerable RF tx.

 

Really... wireless = bad ju ju.

 

Jus my opinion - worth what you paid for it.

[WirelessEye 0]

We use *high* frequency for our video transfer. Send anywhere from 1-4 feeds over each radio too...

 

Don't know if everyone is just to scared or wireless, or if they don't know anyone who can do it correctly...

 

900MHz is a non-line-of-sight frequency that is decent at short range where there is a huge amount of physical barriers between your points, but does not have the throughput needed for efficient video transfer on multiple feeds.

 

You can use 2.4GHz, but I don't recommend it. You would have to do a PTP link, and with 3 feeds, you'll more than likely get only 5-15fps(Max).

 

5GHz is by far your best choice for video transmission, (unless you want to pay for a licensed frequency), as it has the available throughput for video transfer. Since it is a higher frequency it is more susceptable to line-of-sight problems than lower frequencies. Although, we've shot through oak trees at 65ft height and still got a 35 meg link. (At 6 miles)

 

If you do your homework, you can find the "right combination" for video transmission. Don't let nay-sayers discourage you. You can get 20-30 fps at 10 miles with great picture if you do it right.

 

Don't worry about wireless security either, too many people have heard horror stories of open networks and hacking. Encryption methods are abounding for wireless, and our wireless uses military level rotating keys every 15 minutes).

[rory 0]

well ... first we dont have any licence issues here, so I can use 5.4Ghz Encrypted, or any other down here..

 

Second, the tower we were going to use, were well over the height of any trees inbetween, hence the cost .. Our pine trees here arent as tall as yours in the US.

 

Wireless Eye, send me a PM maybe we can work on something with this ..

 

thanks

 

Rory