Tony Williams wrote:

Note: The OP has a similar thread in sci.electronics.design.

Yeah, I tried to post the same thread to more than one group in Google
Groups ("separate multiple groups with commas") but it didn't work for
me. Don't know if you have to have a space either side of the comma or
something...

So I had to rewrite my post and put it in sci.electronics.design

Not very neat but there you go.