Model 40-180 - 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: Model 40-180 (/showthread.php?tid=22694)

---

RE: Model 40-180 - Radioroslyn - 08-15-2021

This is how 37 works. On the pri the 455KC IF signal is delivered from the plate from the 7B7. Thru inductive coupling the signal is transferred to the secondary. 37A is used the adjust the resonant frequency. If you follow the green wire it connects the the plate of the 7C6, diode section. The cathode section is grounded it develops a negative voltage heading back down the green wire. That is your audio signal it goes down thru the secondary of the IF transformer and thru 37 B,D, and C. Those value are not very critical, they are used to filter out IF signal from the audio. As long as 37b and c are not shorted. From there it goes to the top of the volume control and into the audio amplifier.

I'd double check the wiring to be it's correct and there is no shorts from missing insulation. Is your generator in good order and calibration?
If you would keep your measurements in the same decimal place as listed on the schematic. Like mmf, pf, uuf, mf,and uf are fine.

---