[Pillo69]

In the diagram 80 Philco pin 4 of the second valve 36 is grounded. 

In my Philco is connected to ground, so it also has a resistor and capacitor to the central terminal of the oscillator coil. 

I've seen some pictures where also other devices have that connection. 

The connection of the resistor and capacitor is correct ?. A which is due ?. 

Thank you.

[Image: http://s3.postimg.org/jkheaeg5f/106_1.jpg]

subirimagenes

[Radioroslyn]

It appears to be parts 5 and 6 as per the diagram. Your fine.
Terry 

http://www.nostalgiaair.org/PagesByModel...013843.pdf

[Pillo69]

Thank you for your attention.

[Radioroslyn]

You may want to measure the resistance from the unground side of the resistor to the cathode pin of the mixer tube. This will tell you if you will need to rewind the feedback section of the osc  coil.
To check ant coil unplug set turn on with the volume control all the way up (loudest). Measure resistance from the ANT post to gnd post. Both osc and ant coil should read 10 ohms of less. If higher it's time to break out the magnet wire.
Terry

[Pillo69]

The question is that the terminal 4 is connected to ground, the scheme does not go directly to ground, it first goes to the coil, then the resistor and capacitor and finally to ground.

[Radioroslyn]

The 36 tube that is connected to the coil is the mixer, the one with the grounded cathode is the detector tube.
Terry