The PHILCO Phorum
Crosley 148 tube ? - Printable Version

+- The PHILCO Phorum (https://philcoradio.com/phorum)
+-- Forum: Various and Sundry Categories (https://philcoradio.com/phorum/forumdisplay.php?fid=37)
+--- Forum: Other Radios (Non-Philco) (https://philcoradio.com/phorum/forumdisplay.php?fid=12)
+--- Thread: Crosley 148 tube ? (/showthread.php?tid=6151)


Crosley 148 tube ? - Eric - 03-06-2013

Question on the tubes on this radio?
looking at the #57 tube
Trying to trace wiring and want to number the print with the proper pin numbers on the tubes figured out the cathode(5), heater(1,6) and the plate(2) (which is the rectangle on the right of each tube?) but the other three got me is the screen grid always in the middle? I see on some tube prints they are labled G1,2,3. Any help would be appreciated.

Eric

Screen Grid ?
Supp Grid ?
Bias ?

http://www.nostalgiaair.org/PagesByModel/276/M0003276.pdf

RE: Crosley 148 tube ? - Radioroslyn - 03-06-2013

1 Heater
2 plate
3 g2 or screen grid
4 g3 or suppressor grid
5 cathode
6 heater
Never heard of the bias connection on a tube socket.
GL
Terry

RE: Crosley 148 tube ? - Eric - 03-07-2013

Terry

Thanks for helping I should have been more clear in what I was looking for but that is the life of a novice. Referencing the print for the Crosley 148 the 57 tube. Starting from the left on the diagram

The first is that the grid cap going to the tuning cap and coil?
Then the next is the cathode 5
Then the 2 heater leads then 1&6
Then screen grid 3?
Then suppressor grid 4?
and lastly the plate 2

Just trying to understand what is going on
Eric

RE: Crosley 148 tube ? - Radioroslyn - 03-07-2013

Perhaps this will help. I'm thinking that you don't know what the symbols mean??
http://en.wikipedia.org/wiki/Vacuum_tube
Scroll down and you will see a diagram of several types of tubes.
GL
Terry

RE: Crosley 148 tube ? - Eric - 03-07-2013

Terry

Got the symbols let me see if I can refine what I'm looking for.

On this print it is not clear what grid is what to me. There are three grids showing on data sheets they show them stacked and labeled G1,2,3 with pin numbers this print doesn't show that. Is G3 always next to the plate? I the grid on the left the grid cap? So when it asks me the voltage on the screen grid which one do I go to? I guess I'm asking on this print how can I tell which is G1, G2, G3. Can you point me to some more reading material and thanks fo the help.

Eric

RE: Crosley 148 tube ? - Radioroslyn - 03-08-2013

Well typically G1 is the control and is connected to the cap This only applies to receiving tubes. Transmitting tubes usually have the PLATE connected to cap. G2 is the screen grid the middle grid. G3 is the suppressor grid closest to the plate.
Terry

RE: Crosley 148 tube ? - Eric - 03-08-2013

Thanks Terry,
That is what I was looking for, trying to number the print with the pin numbers so I can trace the wiring I had the tube data and pin numbers but the layout on the old print thru me G1,2,3 is confusing enough at this point I needed (wanted) to know which grid was which. Also found today Cunningham Radiotron book online in pdf http://www.tubebooks.org/tubedata/RC12.pdf

Which went with what you said when I looked up the 58 tube it had a nice diagram on page 110.
Thanks again now the real work starts somebody made a lot of changes I will probably be back trying to figure out what I did wrong

Eric