Cy Suckerton II
September 8th 09, 06:42 AM
When the only tool you have is a hammer, every problem looks like a
nail.
Pete Millett is professionally involved in CAd drafting and board
design, so all his tube projects use a big PCB.
This one has some good ideas but I think he would have been better
off with a simpler circuit:
http://www.pmillett.com/hp_8903_software.htm
Since a LOT of cheap TV tubes are out there' I'd have used a
different driver as well, something more linear. TYhere's no reason
to stick with 6.3 v heaters if you are doing DC regulation.
I'd have put the extra money into a custom PT with 1) a full laddered
primary and 2) used a bridge rectifier with center tap for a half
voltage rail. Marshall does that sometimes. In fact using a Marshall
PT and a separate fil and bias xfmr might have been a better way to
go.
I mainly would prefer to do it as a point wired design though. Much
more modifiable and actually cheaper to build.
nail.
Pete Millett is professionally involved in CAd drafting and board
design, so all his tube projects use a big PCB.
This one has some good ideas but I think he would have been better
off with a simpler circuit:
http://www.pmillett.com/hp_8903_software.htm
Since a LOT of cheap TV tubes are out there' I'd have used a
different driver as well, something more linear. TYhere's no reason
to stick with 6.3 v heaters if you are doing DC regulation.
I'd have put the extra money into a custom PT with 1) a full laddered
primary and 2) used a bridge rectifier with center tap for a half
voltage rail. Marshall does that sometimes. In fact using a Marshall
PT and a separate fil and bias xfmr might have been a better way to
go.
I mainly would prefer to do it as a point wired design though. Much
more modifiable and actually cheaper to build.