High power video transmitters

[Thomas English]

I don't think you want to be anywhere near 10 watts of video RF. You may also be interested to know that the company of which you speak has no refund policy.

 

 

I would like to testify to the importance of this. It is better to have to buy one unit and have it fixed 5 times for free than to buy 5 infinately poorer and less versitile units and replace them regularly as they break.

 

I have been through 7 x 2.4ghz RX s and 2 x 2.4ghz TX s in my short career as a steadicam operator.

[Brad Grimmett]

Speaking of wireless....I had an interesting situation recently and I'm wodering what you guys think. I was shooting in a bar and was having trouble with the image breaking up (transmitting with a modulus 2000, receiving with a sharkfin), so I brought out my omni-directional antenna and told the A.C. to switch them back and forth and see what was better. They put the omni antenna on a C stand next to the sharkfin and as soon as they did that the picture got much better. They moved it away and it got worse again. So we ended up just leaving the BNC plugged into the sharkfin and leaving the omni sitting right next to it. Has anyone experienced this before? I guess one antenna was just helping the other pick up the signal. Am I nuts or is this actually possible? I certainly plan on using this method again any time I'm having reception problems.

[Thomas English]

It is very possible that the other antenna was absorbing a reflected wave.

 

Try getting a small sheet of metal on a Cstand and shifting that around your sharkfin, blocking any reflective waves.

 

It is also possible that it is contributing to the antenna! Your own body can contribute to the antenna sometimes! because your other ariel was "cut to the correct" wavelengh, it could have set up a standing wave accross it enabling the signal strengh to increase on your ariel.

 

With UHF/VHF sometimes just the fact that there s lots of metal in an area can "attract" the EMF. Like an inductor in a transformer or lightening! Thus decreasing any reflective interference because you have brought all the energy over to u rather than letting it bounce off the back wall. This is much less possible on microwave.

[Larry McConkey]

The 2 problems with a delay are: 1) using video for cueing actions including focus pulls and zooms and 2) listening to audio at the same time. You can buy fairly inexpensive audio delay units to match the video delay roughly (the delay will vary with bandwidth availability) but then looking at the actors in realtime will be difficult. Most of the directors I work with like to do both: watch the actors directly while referring to the monitor from time to time as well... were it not for the delay, I would be using a WIFI system of some kind because the signal can be so good!

 

Larry