Just finished with Countdown Phaser from Lectric-FX and managed to get hold of a DMM measuring Hz, I tried to calibrate it.
I have changed the Clkrange and Maxfre trimmers to "multi turn" ones.
I jumper T and R, I turn the big pots to full CCW, I switch on the board. It measures 9V and 15V where it should.
I connect black cable (COM) to ground and red (Hz etc) to TP and switch over to Hz. I get about 1.290 MHz. No matter how I turn, it is the same. (If I move around on the board I can get a couple of 50Hz which I guess is from the wall wart or what might remain from any AC). I can also get a few other readings on some of the legs, so I think the DMM is sound, battery and all.
Since this was a big project I decided to solder each component in, then check for continuity from its leg to the eye(s) on the PCB where it was connecting to. Also for each of the socket "holes". It was painstaking and made it all take much longer, but I am trying to avoid cumbersome troubleshooting with so many parts.
So I cannot swear I did not do any mistakes, but I feel I have at least minimized that part a bit.
Any ideas on what could be the problem, why there is no change when dialing the trimmers?
I have changed the Clkrange and Maxfre trimmers to "multi turn" ones.
I jumper T and R, I turn the big pots to full CCW, I switch on the board. It measures 9V and 15V where it should.
I connect black cable (COM) to ground and red (Hz etc) to TP and switch over to Hz. I get about 1.290 MHz. No matter how I turn, it is the same. (If I move around on the board I can get a couple of 50Hz which I guess is from the wall wart or what might remain from any AC). I can also get a few other readings on some of the legs, so I think the DMM is sound, battery and all.
Since this was a big project I decided to solder each component in, then check for continuity from its leg to the eye(s) on the PCB where it was connecting to. Also for each of the socket "holes". It was painstaking and made it all take much longer, but I am trying to avoid cumbersome troubleshooting with so many parts.
So I cannot swear I did not do any mistakes, but I feel I have at least minimized that part a bit.
Any ideas on what could be the problem, why there is no change when dialing the trimmers?