[Heathkit] DX-40 Questions

[Glen Zook]

RCA started out with 3.75 mA for the maximum grid current of the 6146.  Then they dropped it to 3.5 mA and finally to 3.0 mA.  I have found that the 6146 series is very happy with less grid drive.  In fact, all the way down to about 1.75 mA works fine with no drop in output.

Over driving the 6146 series is the most common cause of failure.

Glen, K9STH

Website:  http://k9sth.com


--- On Wed, 11/3/10, rbethman <rbethman at comcast.net> wrote:

The DX-60 manual specifically states to tune the grid to NO MORE THAN 2.5mA or damage to the final will result.
 
It would appear that "they learned from the past".
 
I know in tuning according to this, I have NEVER taken out the single 6146!