Hello friends
Years late as usual, but I've just completed the pic based LC meter 2.0
http://electronics-diy.com/lc_meter.php
Although the device works as it should, current consumption is running at 100 mA , not 10 mA as spec.
'Scoping the crystal oscillator suggests its running at 20 MHz, not the stated 4 MHz.
And my third puzzlement is no cCal ( 1000pf +/-1% ) is fitted or required to be fitted. The assembly instruction states in black and white 'no component in c4 position' and parts list 'C4 - no component.'
To my dissapointment a 1 percent tolerance silver mica capacitor of 1500 pf reads as 1619 pf, well outside the tolerance band of 15pf either way.
Any tips/suggestions/advice to get it more accurate appreciated
Years late as usual, but I've just completed the pic based LC meter 2.0
http://electronics-diy.com/lc_meter.php
Although the device works as it should, current consumption is running at 100 mA , not 10 mA as spec.
'Scoping the crystal oscillator suggests its running at 20 MHz, not the stated 4 MHz.
And my third puzzlement is no cCal ( 1000pf +/-1% ) is fitted or required to be fitted. The assembly instruction states in black and white 'no component in c4 position' and parts list 'C4 - no component.'
To my dissapointment a 1 percent tolerance silver mica capacitor of 1500 pf reads as 1619 pf, well outside the tolerance band of 15pf either way.
Any tips/suggestions/advice to get it more accurate appreciated