TV EXPLORER HD+ manual - Promax

USER’S MANUAL. TV EXPLORER HD +FM Deviation:Measure the frequency peak deviation for any modulatedanalogue carrier in FM.WARNINGWhen at the RF input appear an important number of carriers with a high level the tuningcircuit may become out of control, giving as a result wrong level measurements. To beable to determinate the equivalent level of a carrier group (with similar levels) at the RFinput, it is possible to use the expression:L t =L + 10 log NL t : equivalent total levelL: average level of the carriers groupN: number of carriersSo, if there are ten carriers with a level around 90 dBµV, their equivalent level will be:90 dBµV + 10 log 10 = 100 dBµVObserve that in this case, loss of tuning by overload of the RF input may occur besidesother effects such as tuner saturation and generation of intermodulation products thatmay mask the spectrum visualization.5.14.2 Analogue TV: Measuring the Video / Audio ratio (V/A)In the Audio/Video measurement mode, on the screen appears the followinginformation:Figure 24.- Measurement of the video/audio ratio.In addition to the video carrier / audio carrier level ratio (16.2 dB in previous figure)it also shows the frequency or channel, depending on the tuning mode selected, and theCarrier/Noise ratio.Page 50 01/2011