I have a 587 that has mini tubes, but the schematics I've been able to find all show octals. Could someone point me to a proper schamatic please? I don't see a chassis number and the label is missing. Thanks much!

Hi Stan

Here are miniature equivalents of octal tubes.

12BE6 = 12SA7
12BA6 = 12SK7
12AV6 or 12AT6 = 12SQ7
50B5 or 50C5 = 50L6
35W4 = 35Z5

These tubes require the same circuitry. They just have different basing. You should be able to use the same schematic.

http://www.nostalgiaair.org/PagesByModel/681/M0004681.pdf

Norm

:I have a 587 that has mini tubes, but the schematics I've been able to find all show octals. Could someone point me to a proper schamatic please? I don't see a chassis number and the label is missing. Thanks much!

Hi Stan and Norm,
50B5 and 50C5 do not have the same pin out. Look for the 150 ohm resistor going to the tube that replaces the 50L6GT. If the 150 ohm resistor goes to pin 1, you need a 50C5. If the 150 ohm resistor goes to pin 2, you need a 50B5.
If it goes to another pin, let me know. 50D5?

Best Regards,

Bill Grimm

:Thanks guys! It's a 50B5. Got the radio recapped and aligned. Sweet radio!! Maybe one day I'll actually be able to help someone instead of always asking for help. It's a great education.

Hi Stan and Norm,
: 50B5 and 50C5 do not have the same pin out. Look for the 150 ohm resistor going to the tube that replaces the 50L6GT. If the 150 ohm resistor goes to pin 1, you need a 50C5. If the 150 ohm resistor goes to pin 2, you need a 50B5.
: If it goes to another pin, let me know. 50D5?
:
:Best Regards,
:
:Bill Grimm
: