37-650 buzzing - Printable Version

+- The PHILCO Phorum (https://philcoradio.com/phorum)
+-- Forum: Philco Radio Discussions (https://philcoradio.com/phorum/forumdisplay.php?fid=5)
+--- Forum: Philco Electronic Restoration (https://philcoradio.com/phorum/forumdisplay.php?fid=8)
+--- Thread: 37-650 buzzing (/showthread.php?tid=2839)

---

Re: 37-650 buzzing - Ron Ramirez - 02-03-2011

One end of resistor (46) connects to the control grid of one of the 6F6G tubes, which is pin 5, not pin 4. We'll get to the other end of (46) shortly.

Resistor (52) is connected from the screen grid of one 6F6G (pin 4) to the screen grid of the other 6F6G (also pin 4).

Condenser (47) connects from the control grid of one 6F6G (pin 5) to the screen grid (pin 4) of the other 6F6G.

Resistor (53) connects from the control grid of one 6F6G tube (pin 5, same pin that one end of condenser (47) is connected to) to the other end of resistor (46), and on to B- in the power supply circuit.

Double-check your connections.

You can't always go by a pictorial, they can be wrong. The placement of (46) in the 37-650 under-chassis pictorial looks incorrect to me.

Rely on the schematic instead of the pictorial.

There is a handy website which will give you the pinouts of thousands of tubes, along with their specifications.

http://www.nj7p.org/Tube.php
Using this resource, you can compare these pinouts to the schematic drawing for a clearer understanding of what is going on inside the radio.

---

Re: 37-650 buzzing - wil - 02-05-2011

Yes!!! Switched the resistors per your direction and BINGO...the radio works!! Ron...you've been a hugh help...I really appreciate you sticking with me on this...

Thanks much...Bill

---

Re: 37-650 buzzing - Ron Ramirez - 02-06-2011

Congratulations! Another one fixed...

---