CMA-100 Countermeasures Amplifier
Countermeasures Amplifier (CMA-100)
The Counter Measures Audio Amplifier (CMA-100) is a high gain audio amplifier used to detect and identify certain
types of surveillance devices attached to building wiring such as
telephone wiring, LAN and server systems, AC Power, Alarm wire etc.
The CMA-100 is designed to provide flexible features and will prove
to be very useful in many situations. This amplifier is quite
useful for checking telephone lines and other wiring for hostile
microphones, testing for hook switch audio leakage, and detection
of eavesdropping devices that are sensitive to bias voltages or
The CMA-100 has a balanced input impedance of 50K ohm, can
withstand being attached to live power lines with voltages up to
250V, and provides up to 115dB of gain.
Additionally, the CMA-100 utilizes a unique AGC that can
automatically adjust gain from -20 to 120dB.
Signals as large as 10V peak-peak can still be monitored with
minimal distortions. Manual gain control can be set to 0, 25, 50,
75, or 100dB. Filters can be positioned to FLAT, LOW PASS, HIGH
PASS, or BAND PASS.
This multifunctional amplifier has a built in AC/DC digital
voltmeter, selectable audio filters, and an extremely wide dynamic
Balanced and Unbalanced high impedance inputs provide connectivity
to a variety of suspect wiring.
The CMA100 also provides a bias voltage adjustable between -15V and
+15V DC that is used to activate possible devices that are voltage
or current sensitive. The bias generator is compatible with most
types of line conditions.
All of these functions employ a sophisticated automatic gain
control circuit that is superior to most audio amplifiers.If you would like to purchase this or our other products, or
require a quotation; please contact Granite Island Group by
telephone at: (978) 546-3803, or via E-mail at: firstname.lastname@example.org
- Input Impedance: 50k balanced
- Common Mode Rejection: >75 dB
- Maximum Usable Input: 10V p-p
- Preamp Auto attenuator: 0 to -20 dB ( with overload warning LED )
- Automatic Gain Control: -20 to +120 dB ( includes preamp auto
- Manual Gain Control: 0, 25, 50, 75, 100 dB
- Headphone Gain Control: 0 to 15 dB
- Maximum System Gain: 115 dB manual mode, 120 dB in Auto Mode