[Johnson] Valiant Drive Resistor mod question

[Mike Pagel]

I have a Valiant II and had noticed how warm the Drive knob gets.  A friend
alerted me to the need to address this issue before the existing Drive
control loses its smoke.  Researching the problem led me to Wireless Girl's
discussion of this topic at
https://wireless-girl.com/Projects/AMTransmitters/JohnsonDRIVEresistor.html.

 

She points out that WA1HRL recommends a 5K 5-10 watt resistor on both the B+
and Ground return sides of the control  but that adding the 5K to the Ground
side compromised her ability to reduce Drive on 160 to Spec.  Instead, she
placed a 22K resistor on the B+ side but no resistor on the ground end (note
that her Drive pot had been replaced with a 20K unit instead of the original
25K).

 

Have you done this mod to protect the original Drive control pot?  If so,
how did you do it?  My tentative plan had been to use a 10K 10 watt resistor
on the B+ side.  I'm curious about how others had handled this.  Are there
any negatives to increasing the resistance on the B+ side and not installing
added resistance on the Ground side?

 

Thank you, in advance, for your guidance.

 

73,

 

Mike, K9UW

Amherst, WI