Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

77 low volume
#1

While waiting for parts for my 87 I finished up my 77. All excited I fired it up. No volume until I touched the volume control shaft, top of the 1st rf tube (24), or the coil #5. Checked coil resistance 6.2 ohms from cap of 24 to gnd. matches other coils, volume control pod, ground connections, and voltages, all look ok. Ran a jumper from 24 cap connection on coil to ant. got a little better, but not as good as if you touch it. Some stations you can hear faintly, but others not until you touch. Tried swapping tubes, no difference. Probably something simple staring me in the face. Frustration got the best of me at this point. Any and all ideas welcomed. Thanks ahead of time, Richard
#2

Check for continuity in both windings of transformer #2;
Both sections of coil #5;
All three sections of coil #9 and #10.

Check for B+ on plates of both RF tubes. If missing on either plate, it's a coil winding associated with that tube.

(I assume you already replaces all the wax-paper caps and any out of tolerance resistors.)
#3

Hi Chuck, Thanks for the reply. #2 from volume center tap to gnd. 20.9 ohms, gnd. to tab for coil #5- 6.2ohms. Coil #5 center tap 6.2 and 6.1 ohms. Coil #9- 45.7, 6.3, 1.5 ohms. Coil #10- 48.5, 6.2, 1.5 ohms. B+ voltage on plates 154. All capacitors and out of tolerance resistors were replaced. Also before replacing anything there was a wire bridge on the bc resistor connecting H & J. I removed it since I could not find it on any schematics or updates. The resistor tests good between H & J 2,054ohms. specs. 2,000 ohms. Also a 24k dog bone resistor was in parallel with resistor #12 a 100k. I also remove it. Both seem to have been added a while back. Thanks, Richard




Users browsing this thread:
[-]
Recent Posts
Philco 46-480 Electronic Restoration
I forgot to make mention of it the other day, but last week I corrected another error on my schematic (applies to both R...jrblasde — 09:27 PM
Gloritone 27 Radio
I have a model 27 that someone painted the cabinet brown. I've been trying to sell it for awhile but the cabinet paint m...Jim Dutridge — 02:30 PM
Restoring Philco 96
Joseph Yeah. The situaction is complicated by me living with my family in NJ while mom is in FL. Were it not for my ...morzh — 10:55 AM
Restoring Philco 96
Best of wishes for your mother. I hope she recovers well. My mother struggles with sciatic pain as well, so I am familia...jrblasde — 10:41 AM
Restoring Philco 96
Well, because I am away, I cannot check it. Hope mom becomes better enough for me to get back. I think I will be here f...morzh — 10:27 AM
Restoring Philco 96
Nice find! I hope it completes your console.jrblasde — 08:45 AM
Gloritone 27 Radio
Hello john, That, is the first time I have have seen or heard of that brand and model. Welcome to the party !! Sincer...radiorich — 08:08 AM
370 Norman Bel Geddes trim pieces
Thank you! I’ll probably use the half-round molding and tone it to match the original. Thanks for the replies!Max T — 06:34 AM
Gloritone 27 Radio
I'm kind of late to this thread, but Buzz1151 has a 3 part restore series on the model 27: A little bit of extra t...Eliot Ness — 05:48 AM
370 Norman Bel Geddes trim pieces
You can get half-round moulding in various diameters at any home improvement store. That way the flat edge is uniform. ...GarySP — 12:03 AM

[-]
Who's Online
There are currently 1865 online users. [Complete List]
» 1 Member(s) | 1864 Guest(s)
Avatar

>