U-47/ ef14 voltage question

[telefunk]

David,

Did some maths and figured out the R8 should be 56k to get back down in the right voltage.

But I still have the problem of mic working in cardiod and fig.8 BUT if i try to go even one step to direction of omni the whole mic gets silent and the sound gets back when i go back to cardiod. In about 6-7- seconds....


Any ideas?

 

[telefunk]

David,

Closer examination shows that if I change the polarity voltage in gets silent but comes back in 15-20 seconds.

Do you have the same situation?

If using 100M and 60M bias resistors what about the R10? It's 1G in Oliver's schematic...