I am working on Philco 48-460 that was previously worked on by someone else who installed only two electrolytics condensers rather than the three I notice in the schematic. I am not a good reader of schematics. I see there are three electrolytics, c100A (30MF), c100B (25MF), and c100C (20MF). All three positive connections are near the 35Y4 tube (in the schematic).
Could someone please verify for me the tubes and the pins on those tubes where those positive connections belong?
Thanks.
Posts: 270
Threads: 12
Joined: Nov 2005
City: Nashville, TN
Hi,
Please verify the model of the radio as there's two schematics on Nostalgiaair.
http://www.nostalgiaair.org/PagesByModel...013634.pdf
Both diagrams show the caps mentioned but they are Id'd as C-20 A c-20b and C-20C
The negative is connected to the chassis ground.
The 30 + lead goes to pin 7 (cathode). (Count looking from the bottom of the tube from the keyway, clockwise).
The 25uf is connected to the junction of R8 and R8 also goes to one end of the output transformer.
The 20uf is connected to pin 4 of the 50L6 output tube.
So, as you say, someone worked on the set before you. Often we see added caps across the originals. Bad idea. Other times there are 'extra' caps for whatever reason. Or , they forgot to add one back in.
You are going to use new caps anyway, right? So you will have all three installed correctly.
Gary,
Thank you for your clear advice. This set had two electrolytic connections attached to the junction strip rather than the sole 25MF. The missing link was the connection to Pin 4 of the 50L6.
Thanks,
Decoflair