A while ago I bought an Hallicrafters S-53A shortwave radio. It covers 530 KHz to 54 MHz. It works poorly on the broadcast band and worse on the upper frequencies. Lots of strange noise and dead spots as I tune across the dial
I have found that 2 of the carbon composition resistors have changed vale dramatically. The 27 ohm resistor associated with the oscillator tuning circuit is now 83 ohms. The 330K screen grid resistor on the mixer tube is now 1.36 Meg. All the other resistors are within about 20% . I will replace the 2 obviously bad resistors but I wonder if replacing anything more than 10% off nominal value is worth the effort.
Now about the capacitors, I will replace all those waxy tubular capacitors but just how reliable are those square capacitors with the colored dots? The ceramic disks?
Manual and schematic http://jptronics.org/Hallicrafters/manuals/halli.s-53a.pdf
I have found that 2 of the carbon composition resistors have changed vale dramatically. The 27 ohm resistor associated with the oscillator tuning circuit is now 83 ohms. The 330K screen grid resistor on the mixer tube is now 1.36 Meg. All the other resistors are within about 20% . I will replace the 2 obviously bad resistors but I wonder if replacing anything more than 10% off nominal value is worth the effort.
Now about the capacitors, I will replace all those waxy tubular capacitors but just how reliable are those square capacitors with the colored dots? The ceramic disks?
Manual and schematic http://jptronics.org/Hallicrafters/manuals/halli.s-53a.pdf