In-line A/V tester for LNCs

Most low-noise converters (LNCs or LNBs) for satellite TV reception require either a fixed supply voltage of + 15 V Of one which is switched between + 13 and + 15 V. This voltage is supplied by the tuner, via the coax cable. The LNC current consumption is typically between 100 mA and 400 mA. The low-cost V/ A tester described here allows you to detect short-circuits in the coax cable, and faults in the tuner. The little instrument has a current range of 0-1 A and a voltage range of 10-20 V.