Frequency Range 1.5MHz-1.2GHz useful indications to 2GHZ. AM and FM measurement over full range LED indication of lock, level low and high Analogue display CCIT VP53 Psophometric Filter De-emphasis network.
Description:
The Automatic Modulation Meter TMM2800 has been designed to simplify the task of measuring amplitude and frequency modulation on signals on the range 1.5MHz to 1.2 GHz. By eliminating the need to tune a local oscillator and make level adjustments the TMM2800 speeds up measurements and reduces errors.
AM and FM measurements can be made at full accuracy over the frequency range 1.5MHz to 1.2GHz and with reduced accuracy and sensitivity to 2GHz. On FM, five ranges are provided with fullscale readings of 1KHz, 3KHz, 10KHz,30kHz and 100kHz deviation. Peak positive, peak negative or mean deviation can be displayed. On AM five ranges five full scale readings of 1%, 3%, 10%,30%,and 100%. Peak, through or mean of percentage modulation can be displayed.
For ease of measurement, three bandpass filters with nominal upper cut-off frequencies of 60KHz, 15KHz and 3.5KHz, a CCITT psophometric filter the recovered modulation.
The different ranged and functions are selected by front panel push buttons with LED’s providing positive indication of function.
Specification:
RF INPUT
Frequency Range 1.5MHz to2.8MHz, 3.2MHz to1.2GHz with a useful response, with reduced sensitivity, to at least 2GHz.
Tuning Automatic tuning selects the largest available signal. Correct operation requires spurious signals to be >10dB below the wanted signal.
Acquisition Time Typically les than 100ms to locate and lock to carrier signal. Setting time for the demodulation and AF circuits is additional and is typically 1 second.
Lock and Level Indicator A LED indicates that the instrument is locked to an input signal and that the level is within range.
Input impedance 50 ohms nominal.
Input Level The unit will lock ad measure modulation for input carrier levels in the range 2mV to 1V. Full specification for noise, accuracy etc. only applies over the input 10mV to 1V.
Maximum Safe Input Level 0.5 continuous.
Local Oscillator Feed-out Typically < -60dBm.
FM MEASUREMENT
FM Ranges Five ranges with full scale deviations of 1KHz, 3KHz,10KHz and 100KHz.
Accuracy 2% of full scale. See Audio filter specification for additional error due to AF response. Residual FM is additional. Resdual FM<20Hz at 100MHz. <100Hz at 500MHz,<200Hz at 1000MHz.
Distortion <1% at 50KHz deviation with a 1KHz tone.
FM Measurement Modes Peak + Ve, Peak Ve and Mean deviation.
AM MEASURMENT
AM Ranges Five ranges with full scales indications of 1%,3%,10%, 30%,100%.
Accuracy 2%of full scale. See Audio filter specification for additional error due to audio response. Residual AM is additional.
Residual AM less than 0.5% with a 15KHz bandwidth selected.
Distortion <1% for 50% AM with a 1KHz tone.
AM Measurement Modes Peak, Through and Mean of peak and Through.
AUDIO FILTERS
60KHz Bandpass Filter 25Hz-60KHz 1dB, typically 12Hz-72KHz 3dB with HF roll off at 80 dB /decade.
15KHz Bandpass Filter 25Hz-15KHz 1dB, typically 12Hz-19.5KHz 3dB with HF roll off at 60dB/ decade
3.5KHz Bandpass Filter 25Hz-3.5KHz 1dB, typically 12Hz-4.0KHz 3dB with HF roll off at 100dB/ decade.
CCITT filter complies with CCITT Volume VP 53
De-emphasis network 750us de-emphasis, 3dB bandwidth typically 12Hz to 212Hz.
HF roll off 20dB/ decade.
AF OUTPUT
Demodulated AF Output Front Panel BNC.
AF Output Level OdBm corresponding to scale deflection.
AF Output Impedance 600ohms.
IF OUTPUT
IF Output Front Panel BNC.
IF Output Level Typically 100mV
DISPLAY
Type Moving coil meter with 0-3,0-10 and 20dB scale with % and KHz notation.
Frequency Range 1.5MHz-1.2GHz useful indications to 2GHZ. AM and FM measurement over full range LED indication of lock, level low and high Analogue display CCIT VP53 Psophometric Filter De-emphasis network.