telefunken: Low AM volume

Hello All:

I could use some direction on troubleshooting this radio.  I have recapped it and replaced the selenium rectifiter.  The radio plays beautifully on FM and with an outside source through the phono input.  On AM, however, I have to turn the volume all the way up to barely hear the strongest AM stations.  The schematic only gives a few voltage specs which are all fine.  I've tried substituting tubes and have checked resistors but haven't found any issues.  I do have continuity from the antenna jacks to the AM switch, but f I touch the ferrite antenna there isn't any change in reception.  I've used a signal generator to generate a 460khz signal connected to an AM antenna to "broadcast" it and the radio picks up the tone.  On FM, the magic eye responds as expected.  On AM the magic eye stays open and doesn't move when tuning anywhere on the dial.  Poking around with a wooden stick hasn't uncovered any bad solder joints.

 

Any suggestions would be appreciated.

 

Thanks,

 

Mark

Attachments:

• Gavotte Schematic 2 (131 KB)

To thank the Author because you find the post helpful or well done.

Problem solved.  Turned out there was one bad resistor in the AGC circuit that tested OK when the radio was off.  

To thank the Author because you find the post helpful or well done.