Instrumentation and prototype design:

Since 1994 Prototype Express’s instrumentation design activities has been involved with a number of projects. The projects have ranged from designing the electronic circuitry for various multimeters to 10MHz function generator as well as equipping other previous designs with GPIB interface. These have been custom designs for instrument manufacturers.

  • GPIB interface for 600 MHz frequency counter.
  • 3¾ digit full spec autoranging hand-held multimeter.
  • 3½ digit full spec autoranging hand-held and table-top multimeters.
  • 4½ digit autoranging multimeter with GPIB interface.
  • 10MHz full spec function generator.

The multimeters designs incorporate state of the art technology for long battery life and protection. They include features such as autoranging and transistor test for the 3.5 digit hand-held version to top of the range 4.5 digit table-top multimeter with GPIB interface. Prototype Express can provide custom solutions to your needs to complete your product range.

GSM Repeater

‏There are many problems in GSM networks, like as weak signals, and Ping-Pong effect, which causes disconnection during a call. KMR-900 is a very powerful GSM repeater and a comprehensive solution for the above problems. This system is ideal for smaller application to gain the strong signal for the areas like Offices, Underground areas, Factories, Hotels, Shopping malls, Parking Garages, Banks, Restaurants, Houses and any in-building dead zones.

Now with “KMR-900” you can stay connected wherever you are.


  • Compact-design for easy installation and operation
  • Economical solution for in-building dead zone
  • Automatic Gain Control *
  • Level meter
  • Automatic shutdown
  • Alarm LED
  • Long-term reliability
  • *This function limits the output level to a fixed level


Frequency range:  Up-Link 890-915 MHz

                                 Down-Link 935-960 MHz

Output Power: 12dBm max @ 2tone IMD£ -36dBm.

Maximum input power: -25dBm

Maximum gain: 70dB

Ripple:  <= 3dB

NF: <= 7dB

Auto gain control range: 31dB

Auto gain control steps: 1dB

IMD: <= -36dBm

VSWAR: 1:1.5

RF I/O ports: SMA female connector

Power: DC 9V 2A. (AC/DC Switching Adapter, AC 100~240V)

Dimension: 160x200x40mm

GSM Blocker

GSM Mobile blocker provides the final solution in any area where cellular communications frequently cause annoyance either by loud incoming call rings or loud telephone conversations. GSM Blocker is suitable in executive offices, board meetings, conferences, seminars, libraries, cinemas, religious places, public transport, concert halls, restaurants and educational institutions etc.


  • Compact-design for easy installation and operation
  • Adjustable coverage range to eliminate unwanted neighborhood interferences. (5 Steps)
  • Long term reliability
  • Backup battery facility


Frequency band: GSM 935-960 MHz

Output Power: <0.25 watt

Coverage area: 1-15 m (radius) adjustable in 5 steps

Power Supply: 9-25 Vdc/1A

(Possibility of using 12Vdc or 24Vdc backup battery)

Dimensions: 14.5×12.5×4.5 cm

Weight: 500 gr

Prototype Express can provide you with:

  • Low cost development.
  • Fully documented development packages for the designs.
  • Fast development schedules.
  • Custom software development for instruments with Personal Computer user interface.
  • Design of custom instruments for special applications or special requirements such as low power or low weight.