Nominal input impedance is 1M. The kit is supplied with a small plastic case complete with a screen-printed front panel. It requires a 9-to-12vDC power supply. A standard plug pack, center positive, can be used. Current consumption is approximately 175mA.

Case dimension: 13 x 7 x 4 cm.

The kit is constructed on two printed circuit boards (PCBs). One is double-sided, through-hole-plated, and the other is single-sided. Both PCBs have a component overlay for ease of assembly.

Assembly is straightforward. Start with the lowest height components (resistors, diodes, etc).

Note: There are five (5) links that need to be installed. These should be added before the IC sockets. Use the wire offcuts from the resistors as the links. Fix the 5V regulator and heatsink to the PCB using the nut and bolt provided. When inserting diodes D3-6, space them up from the PCB by about 3mm (1/8"). This will help with heat dissipation.

Before applying power, check your wiring and assembly very carefully. Make sure that polarity sensitive components such as diodes, transistors, ICs and electrolytic capacitors are inserted correctly. If everything seems OK, connect a 9-to-12V DC plug pack to the power input socket. The LCD display should spring to life. The "Gate" LED should be flashing and one of the other two LEDs should also be on. With the signal input "floating" it is very likely that the display will show a random reading due to stray RF pickup. If the unit appears "dead" then check the 5 volt output from the regulator. If there is no 5 volts there, check the input to the regulator. It should be greater than 7.5 volts. If there is no voltage there at all, check the polarity of the plug pack - it should be centre positive. Are diodes D3-6 inserted the right way around? It you get a reading but it is less than 7.5 volts then you may need a higher voltage plug pack or you may need to strap out some of the diodes. Once you have determined which board has the fault, check it for shorts between the PCB tracks themselves. Look for solder "bridges" between component pins. If all still looks OK then start taking out the 100nF decoupling capacitors across each of the ICs. These have been known to go "short circuit". Another possibility is that the regulator is faulty, although this is unlikely. If all seems well then the next thing to do is connect it to a repetitive signal source. A frequency generator or the calibration output of a CRO will do fine. Check that you get a reading on the display. If not, check the signal on X1 and X2, using either a CRO or a logic probe. If there is no signal on those pins then the fault is on the interface board.