Tescom ACT6000 - 12.4. Guide for generic manual transmissive measurements

ACT6000 User Guide – January 2021 Page 43 of 52
12.4. Guide for generic manual transmissive measurements
- RMS Noise in Base Band with Generator & Meter
The RMS Noise measurement in Base Band can be performed in wide band, or in limited
band or in weighted band (with Psophometric or C-Message filter).
For this measurement it is possible to use the “RX” section of the Generator & Meter.
Set the instrument as follows:
- dBm by F1
- TX Off by F2
- 4W Bal by F3
- Normal by F4
- DC-Inp * by F5
and then:
- RX Impedance: (eg. 600 Ohm)
- Measurement Mode: (eg. Wide BW)
- Band Filter: (eg. Psophometric)
- Connect the line to a-b of the RTX
Read in RX Level the Noise level.
- Spectral Noise / Level with Spectrum Analyzer
The spectral measurement of the Noise / level, in Base or Medium Band, can be
performed in limited band by the Spectrum Analyzer. Set the Instrument as follows:
- dBm by F1
- TX Off by F2
- 4W Bal by F3
- MaxVal by F4
- DC-Inp by F5 (for maximum level
accuracy in very low frequencies)
- Vo Rif for the best trace display
- dB/Div for the best vertical resolution
- Fc (kHz) for the Base or Medium
Band centre or RX Band (for one of the High
Bands).
- kHz/Div for the Medium Band limit
- Zo RTX: (eg. 100 Ohm)
Connect the line to a - b points of the RTX connector.
The setting on the example shown it is used to measure the noise on the typical copper
pairs for the transport of ADSL2+ stream, where the bandwidth is few kHz to 2 MHz.
Long Time Noise / Level Monitoring
After the measuring parameters setting on Medium Band, connect the USB Pen-Drive
(empty) and press “0” and “Enter” of the keypad. The spectral signal will be saved on the
Pen-Drive every two seconds (about) until the “0” key is pressed again. The analysis of the
storage data (related to the time) will be possible by the new PC Utility named
“Spectrum.exe” downloadable from this web page https://tescomusa.com/pages/act6000-
applications.
Note *) this is the condition for maximum level accuracy, however if a DC Voltage (eg. line feed) is
found, the front-end will be decoupled automatically by two capacitors.