EGSM900 (880 – 915MHz)
GSM1800 (1710 – 1785 MHz)
UMTS 2100 (1920 – 1980 MHz)
SA918-196 Directional Antenna System
The SA918 antenna system is designed to enhance the detection capabilities of the GSM196 mobile phone detector. The lightweight assembly (approx 600grams) allows operators to more accurately pin point the location of an operational phone. The detection characteristics also allow the unit to reject unwanted signal reflections from other sources. The antenna effectively amplifies the signals being supplied to the 196 thereby increasing the range of the unit by as much as 50%.
The assembly can be used, either with the handle or mounted on the operator´s forearm. When used on the forearm, a velcro strap is provided to ensure the safety of the assembly. For external searching the unit can be inverted and elevated by means of a variety of standard extension poles which can be fitted into the hollow handle. The assembly also incorporates a standard camera fixing so that it can be attached to a normal photographic tripod.
Use in Prisons
The SA918-196 was designed specifically for use in prisons and can greatly increase the detection capability. In situations where multiple mobile phones are in operation on a wing at the same time, it can be difficult to identify the cell containing an active phone simply by using signal strength alone. The GSM196 when used with the SA918 allows the officer to a scan specific direction with rejection of signals in all but the direction the antenna is pointing – see polar plots.
The assembly can be mounted on the officer´s forearm who can then simply walk passed cells on each landing /level. The GSM196 will then indicate which cell(s) have active phones in them. Once activity has been detected on a wing the assembly can be setup to monitor specific parts of the wing from one end over a period of time.
The SA918 assembly greatly improves the detection and location capabilities of the GSM196 by reporting direction as well as signal strength to search team. With a line of sight range in excess of 500metres for 2G registration signals, the SA918 can be used to identify which accomodation block contains an active phone.
On approaching the block the antenna system can help quickly identify which part of the block the phone is actually located in. The SA918 assembly can also be used with the new GSM196R, which a special version of the 196 which contains a radio transmitter. The 196R in conjunction with SA918 can be left to monitor a specific accomodation block and signal back to the security office all incidents of phone activity.