The PHILCO Phorum

Full Version: tube numbering
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
Hi Guy's,
Does anyone know the numbering sequence on a number 42 tube(6 pin).
I need to know which is number one pin.
murf
The two thick pins are 1 and 6. Pin one should be the thick one on the right viewed from the tube bottom IIRC.
That's what I thought.
Wanted to make sure.
Thanks
No, no, no, no!

Pins 1 and 6 are indeed the larger of the two pins, but as viewed from the bottom Pin 1 is the large pin on the left. You then count clockwise from there - 2, 3, 4, etc.

Take a look at this link - it shows the correct numbering for the 42:
http://www.nj7p.info/Common/Tube/SQL/Tub...hp?Type=42
Looking at the tube from the bottom? Under the chassis looking at the bottom of the socket I thought it was on the right... Yikes... Hope I didn't hose you up!
Yup, from bottom because that's how the repairmen or builder sees it. The fatt pins on old tubes are always the filament.
An RCA Receiving Tube Manual is a good thing to have. They diagram each tube and have the pin numbers (bottom view).

For the older sets with tubes like the 42 you should have an older manual, as the newer ones list the older tubes in the back of the manual but do not include the pin diagrams.

FYI a tube substitution manual is another good resource to have on your bench.
The anti-intuitive nomenclature was no doubt invented by a very clever Kangeroo.

You can get old time manuals and keep you reading for the next century here:

http://www.tubebooks.org/technical_books_online.htm