[Collins] KWM-2 S-Meter Sensitivity

[Byron Tatum]

Hello-
    Recently I  took a  516F-2 chassis and built a new power supply using the 
Heyboer power transformer and matching 3 chokes. In general I followed Jim 
Garland W8ZR's build that is detailed on his website.
    This newly-built 516F-2 lowered my low-B+ coming from 325 VDC (measured on a 
standard 516F-2) to 285 VDC. Plus, the filament voltage is a little closer to 
spec. I am using the 125 VAC tap on tyhe Heyboer primary as my line voltage 
runs between 125 and almost 130 VAC at times.
    I noticed a change in the receiver section operating a this lower 
voltage: In oder to get a full scale S-Meter reading with the RF Gain backed off 
fully I need to run the "Receiver Gain Adjust" pot wide open now, whereas 
previous to lowering the voltage I was running the gain adjust at about the 70% 
position. I do not wish to have to keep the gain adjust wide open as the 
receiver has more than enough gain at 50% to 75% open on this adjustment, but as 
I lower the setting of the gain adjust pot the S-Meter full scale reading is 
lowered correspondingly, and quite considerably. I plan to always operate this 
KWM-2 on this newly built power supply so I need to make a permanent change in 
the S-Meter circuit.    
    Seems like I heard mention of a resistor to adjust the value of that set the 
S-Meter full scale range. Thank you for your time,
                                                                                
                Byron WA5THJ