RC India

RC Equipments => Servos, Gyros and All Electronics => Topic started by: linked on June 02, 2012, 05:42:37 PM



Title: 5.8Ghz video tx/rx
Post by: linked on June 02, 2012, 05:42:37 PM
Hi,

I am making a project that consists of three wireless cam. I have already bought 520tvl NTSC 12V cam. Now I am confused with transmission system. Is it possible to get video feed from three different 5.8ghz transmitter through one 5.8ghz receiver? Or I should buy three receivers? I am not veteran on this.
Please let me know.

Thank you.


Title: Re: 5.8Ghz video tx/rx
Post by: girishsarwal on July 10, 2012, 04:12:31 PM
Technically yes, practically, depends on your receiver.

If your receiver has support for more than one channel (slightly apart in frequency), Each camera can be set to transmit on a different channel (so no interference is caused). On the receiver, you can cycle through each channel, and a different feed will be shown. If you have a manual with the unit, it should have all the information.

GS






Title: Re: 5.8Ghz video tx/rx
Post by: gauravag on July 10, 2012, 04:19:10 PM
IMO, Bad idea to have multiple transmitters on your airplane in a frequency band so close to each other. Use a RC video switcher, to switch between cameras, and use a single Tx/Rx.


Title: Re: 5.8Ghz video tx/rx
Post by: girishsarwal on July 10, 2012, 04:36:05 PM
I tend to agree with gaurav, its better to be safe than to be sorry, the more waves you have meeting in space, the higher the chance of rogue signals, and it can be bad if they interfere with someone else's model if not yours

These systems can fairly provide clear feed at adequately separated channels. I use a 2.4 Ghz surveillance camera at home, giving out 4 feeds from separate cameras, and all in close proximity (~3ft) to my wifi router, which is again 2.4 Ghz - all works great on separate channels, but then it wouldn't hurt me if my internet connection goes down for a minute, which is not the case with a flying model...

In all cases, please test and consult the manual.


Title: Re: 5.8Ghz video tx/rx
Post by: rcforall on July 10, 2012, 04:37:33 PM
A 3 way camera switch with a single tx is the best bet .
Dont know about humidity levels in your area but  in humid cliamtes 5.8 G is a very bad option http://fpvlab.com/forums/archive/index.php/t-896.html?s=ee1408fdd0a929947f904b16a673ae80

I have never been able to get range out of 5.8 g @ Chennai , I suppose it is to do with the humidity , spoke to another taiwanese friend and he also said 5.8 does not work well there due to humidity.
So check out the humidity before selecting your  frquency.

Further we have experienced that a high power video tx in 900 mhz has masked a 2.4 G RC rx on board when they were in close proximity the problem was resolved by shifting the 2.4 G rx to the tail and placing the 900 mhz closer to the nose.
so with 3 tx's operating in very close proximity though in theory the frequencies are different in practice there could be interference due to rouge or spurious emissions.

Sai