Video Transmission

Undercover Portable Video Surveillance Equipment

There are a number of methods of carrying out portable or mobile video surveillance. In this document we try to provide an overview of what we can recommend and what has been successful for us.

Video Glasses Camera
The glasses are typical glasses. The only way to hide the cables is in the glasses frame. The camera can not be seen except by very close inspection and even then, it is not recognisable as a camera.

The advantage with the glasses is that what you look at is where the camera is focused. This is ideal for 1 man operation.

The camera chip is built into the nose bridge. Cables are from the CCD chip in the nose, along the frames, through a neck strap and into a small box that clips to the belt. This box also contains batteries to power the camera and there is a video and audio output sockets. The glasses captures both video and audio.

From the box we usually connect to :
a) A Portable video recorder for direct recording. The recorder must be activated before the start of the operation unless it is a type that can be fitted with a remote controller. This records video and audio. Excellent quality.
b) Attaching a video transmitter with battery to your belt and connecting from the camera box to the transmitter.

The advantage is that a remote operator can view and listen to the meeting and will be available if help is required. The suspect will not have access to the tapes even if he discovers the transmitter system.

Care must be taken to avoid blocking the radio signal from the transmitter. The receiver side can be more mobile and may have to change positions to improve the signal. This is the reason we have a number of different receive aerials. Practice is essential.

Also available is a button, pen, wrist watch camera and many other ideas. It is not always easy to align the camera to get the right pictures.

Miniature cameras can also be built into other items by us such as a tie, badge, brooch or a plain flat packet that fits into a pocket with a hole.

VIDEO CELLPHONE
We have taken a GSM cellphone case and installed inside a colour camera with good resolution.

Our transmitter is also built into the cellphone case. The battery pack is modified to provide the correct voltage to the camera and transmitter. The aerial is made to look like a normal cellphone aerial. Low power transmitters are used for size and battery consumption.

Altogether the unit looks like a normal cellphone. Unfortunately it does not work as a cellphone as we needed the space for our equipment. If any one asks - "sorry the battery has gone flat."

Because the transmitter is not close to the persons body, the transmitter is more efficient. With our receiver system and on 2.4 Ghz, we average about 300 meters distance at ground level and almost line of sight. Battery life is about 3 hours depending on its charge. Distance will definitely be better if the receiver is higher up.

The cellphone has become one of the most common items that every one is carrying and is therefore the least obvious.

We have had very good results.

MICROWAVE VIDEO RECEIVERS
The most popular receiver we sell is the VRX-2400B complete self contained attache case system.

A person carrying an attaché case into a hotel, offices or other places is completely natural.

The attache case contains the microwave video receiver, channel selector switch, field strength meter, four field motion detector. Outputs are provided for an earphone, video & audio to an external monitor or recorder. The input sockets are for playing back a video from an external source.

A remote control output socket allows for connection to a suitable recorder. This socket is controlled by the internal motion detector. This is ideal for long period observation so that the operator does not have to watch the monitor continuously. If a suitable recorder is connected, this socket will automatically activate the recorder.

Monitors are optional.

A 4.5" colour LCD monitor can be included in the case for the operator to view the scene. A separate recorder must be fitted.

A Sony portable Hi-8 video recorder with colour monitor can be installed. This will allow viewing and recording at the same time. A remote controller for the Sony is also available. This provides simulated time lapse recording with remote control.

AERIALS
The transmitter aerial is limited in size as it must usually be hidden or disguised.

We therefore rely a lot on the receiver section to be sensitive.

Different aerials are available with different gains and results.

The normal aerial is used where the signal is strong enough. When the signal gets weak, we switch to the 10db Yagi for improved performance. If this is not strong enough, we then use the 30db Yagi. The operator must use his judgement and the signal strength meter and experience to select the right aerial.

The stronger the aerial, the more directional it becomes and if it is too strong, the picture will start ghosting.

Practice makes Perfect.

TRANSMITTERS
We also supply other types of transmitters. Available are 1 Watt, 2 Watt and 5 watt. A portable repeater is also available.

Our standard type is 100mW. This can accept any composite video signal for transmitting. It operates from 12v DC.

It is an ideal unit for fixed installations. The camera can be at a remote place and wired to the transmitter. It requires 12v DC. The output socket is a 6 pin circular type that feeds 12v DC to the camera and video/audio back from the camera. We usually use about 10 meters of 4 pair ordinary telephone cable to the camera. This cable is not as suspicious looking.

Our VID-PIR is a camera built into a PIR case and comes with 10m cable and 6 pin plug complete. It can plug directly into the transmitter. This applies to other disguised cameras we can build.

Please note that we have the ability to build transmitters from 1.2 Ghz and up to 10 Ghz. Different output powers are also available. These parameters depend on your licence or the restrictions in your country.

Video Transmission -> Video Surveillance