[Boatanchors] ongoing Johnson adventure

[Robert Nickels]

On 2/11/2017 7:22 AM, Rob Atkinson wrote:
> Bob,  What are these tv or power transistors I often hear about?  Are they
> still in production?  Do you have any model numbers that can be
> searched?  What transistor terms am I searching for?

Hi Rob,

I got to thinking about using a power FET instead and found that someone 
has already done that, and since FETs are more akin to vacuum tubes I 
like this method better.   The STM part shown is overkill, with an 800V 
11A rating,  but it's $5.57 from Digikey. Cheaper N-channel Power 
MOSFETs with sufficient voltage and current ratings should be fine.

Here is a snippet showing the driver pot replacement from the Johnson 
Ranger redesign by WA4DSP:

http://i.imgur.com/gVP91ui.png

73, Bob W9RAN