[Amps] Drake L4B 50K Resistors HOT!!

[Jim W7RY]

I was just repairing a Drake L4B that I picked up from my want listing on QTH.com. I just happened to measure the temperature of the 50K 50 watt resistors in the power supply with my infrared thermometer and WOW!!  

The middle of the resistors run 510 degrees f !!  I could not believe it!

Needless to say there outta here!  I won’t need them anyway. I’m using the amp to prototype my QSK board for the Drake L4-L7 amplifiers that will use resistor cutoff bias instead of the +120 volts that the resistors provide.

73
Jim W7RY