(28-08-2014, 07:08 PM)pwdrive Wrote: I'm not an expert in this field, just trying to get a handle on it all.
Lawrence.
Lawrence - then that makes two of us!
Just one further thought. Despite the reference to using a bulb to monitor crystal current, which repeatedly appears in successive editions of the RSGB H/B and the ARRL H/B (up to 1974: I don't have a later edition), in "Radio Amateur Techniques" (4th. ed., 1974, Pat Hawker, G3VA), refers to that practice as dating from the 1930s when the old and chunky 10X crystals were available. Now looking at the cct. that John has presented, (which is clearly an American drawing), the cct. refers to 'pin2' and 'pin 4' of the crystal. Modern crystals don't have 4 pins in my experience. Therefore . . .
However, be that as it may - as soon as I can find a bit of spare time, I shall build a simple crystal oscillator as close as I can to the one that John has presented in his OP. Then I can take some measurements, which, hopefully, will throw some light on this matter.
Al.
