[TenTec] Centurion Plate Current Meter

[Carter - K8VT]

Michael Tope wrote:

>  I am checking out a Ten-Tec Centurion 422 (2 x 3-500z) amplifier for
>  a friend. This morning I fired it up on 20 meters (into a dummy load)
>  for this first time. Everything looked good (output power, tuning,
>  etc) except for the plate current meter. For some reason the plate
>  current meter on this unit overshoots horribly (close to full-scale)
>  and then oscillates back and forth a few times (~+/- 200mA) before
>  settling to the key-down reading. Is this normal for this meter? The
>  grid current/multimeter doesn't do this, nor does just about any
>  other meter I ever seen.

No...my Centurion meter does not act this way. A likely  possibility 
could be that it is indicating what it is actually seeing--some type of 
parasitic or instability. Try subbing an external meter if you can (I 
mean VOM or whatever-I realize you will not have a spare Centurion 
meter) and see if it acts the same way. I suspect it will.

The only control that appears to be in the circuit is R1 (10 K pot) on 
the 81540 Display board that is used to set the correct value of plate 
current.

!!!! BE CAREFUL AROUND HIGH VOLTAGE !!!!

Good luck es 73,
Carter K8VT