Taming the HH Scott 208

[dcgillespie]

A concept schematic is attached to give an idea of how the heater regulator has been implemented into the Scott design. Also shows how the bias circuit has been reworked as much as possible largely according to other Scott designs to minimize any loss of original integrity. In other words, I tried to keep the 208 as much a 208 as possible by minimizing the intrusion of the modification into the design. There's no magic tricks I'm hiding by not drawing out the Heater and EFB regulator circuits. It was more just a matter space and primarily emphasizing the implementation, rather than making the project specifically about those regulators.

Dave

 

[gadget73]

aha, that explains the H-K thing. Its on the ground side, so nothing to be concerned with. I don't know why but I was envisioning the 19EA8 heaters taking the place of the resistors between the rectifier and the first filter cap. That certainly couldn't have worked out having more than 400v difference between the heater and cathode.

 

[kward]

Using the heater string to shave off some volts from the B+ supply would not have been my first inclination, nor even my second inclination on how to solve this! Overall, that's a nice bit of engineering--and simple!

"In every field of inquiry, it is true that all things should be made as simple as possible – but no simpler." That seems to apply here.

Kevin

 

[darbacox]

My model is différent ! without bias adjust .. it's automatic !