I have a Stewart-Warner 9151-A (AM/FM/Phono input) that has weak FM reception even with a hi-fi dipole antenna connected to it. It cannot receive stations above 99.7 MHz; unlike the Philco 52-641 posted below, the tuner is in the correct position. (No problem with AM reception.)

The strongest station comes in at 97.9 MHz; even then, I have to adjust the volume much higher than for receiving AM stations. Recently, I replaced the line filter and output plate bypass capacitors and the FM antenna isolation resistor; all of which seemed to help improve reception. Reception quality varies if I walk around the room. Also, if I connect and disconnect the dipole antenna (using clip leads connected to the unit) the tuner has to be readjusted slightly. The basic FM antenna with this unit is a wire connected to the FM antenna terminal, through a 100pF capacitor, to one side of the AC line cord.

This radio was used exclusively on AM since it was new. Are these old FM receivers just difficult to work with? Or is this another alignment problem? Thank you for your assistance.

: I have a Stewart-Warner 9151-A (AM/FM/Phono input) that has weak FM reception even with a hi-fi dipole antenna connected to it. It cannot receive stations above 99.7 MHz; unlike the Philco 52-641 posted below, the tuner is in the correct position. (No problem with AM reception.)

: The strongest station comes in at 97.9 MHz; even then, I have to adjust the volume much higher than for receiving AM stations. Recently, I replaced the line filter and output plate bypass capacitors and the FM antenna isolation resistor; all of which seemed to help improve reception. Reception quality varies if I walk around the room. Also, if I connect and disconnect the dipole antenna (using clip leads connected to the unit) the tuner has to be readjusted slightly. The basic FM antenna with this unit is a wire connected to the FM antenna terminal, through a 100pF capacitor, to one side of the AC line cord.

: This radio was used exclusively on AM since it was new. Are these old FM receivers just difficult to work with? Or is this another alignment problem? Thank you for your assistance.

Hi Mark

Since you can not receive stations above 99.7 the oscillator might stop working. It is easier for an oscillator to operate on lower frequencies. This might also account for weak signals in general. The oscillator is usually combined with a RF or Mixer stage. It could be caused by the tube itself or low voltages. Can you identify the oscillator tube?
Norm