38-7 Tone Control - 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: 38-7 Tone Control (/showthread.php?tid=18133)

---

38-7 Tone Control - Crist Rigotti - 03-23-2018

I completed my restoration of this console radio and I noticed that the 3 position Tone Control doesn't seem quite right.  In the "first" position after you turn on the radio the tone is lets say bright.  Then in the second position, there isn't any change in the tone.  Then in the third position, there is a marked difference with the tone being lower and a lot less "noisy".  Is this normal?  It seems there should be a difference between all 3 positions. Tone control is #39 in the attached schematics.
Schematics are attached.

---

RE: 38-7 Tone Control - KCMike - 03-23-2018

Crist looks like the control is showing only two connections when you switch it. 1st pos. the .006 cap is in circuit. 2nd pos. no connection and 3rd pos. .008 and .03 cap in circuit. Maybe someone can explain further about why its noisy in pos 3.

---

RE: 38-7 Tone Control - Radioroslyn - 03-23-2018

The 1st position the set is off so it doesn't effect on the tone.
Position 2 looks like it would be the normal position as it doesn't have any high frequency cut .
#3 has a slight bass boost.
#4 has a lot of high rolloff.

Would check the obvious suspects if it's not working. Tone sw contracts, proper connections, and the tap on the volume isn't open.
GL

---

RE: 38-7 Tone Control - Crist Rigotti - 03-26-2018

Yup, the Tap on the volume control was open! I have a new one coming from Mark Oppat.
Thanks everybody!

---