[Hallicrafters] A question on tube socket pin-out

[Chuck McGregor]

Skip & all
I just sent Skip a scanned tube base chart from the 1935 ARRL handbook. 
  Then I read Mike's posting and realized that it didn't match..... 
There apparently was a change in the pin numbering standards sometime 
after 1935.  The 1935 ARRL data, attributed to RMA standards, shows the 
large pins as always numbered 3 and 4.  This doesn't match later data.

73,
Chuck

Mike Everette wrote:
> Do you not have access to an older ARRL Handbook?  Base diagrams for most tubes are given in the handbooks prior to about 1970.
> 
> As you look at the base of the tube, at the actual pins, the #1 pin of tubes like the 86C6, etc is always the LEFT and LARGE pin and the others are numbered clockwise from that one.  So, pin #6 of a 6C6 is the RIGHT hand large pin.
> 
> The large pins of these sorts of tubes are the filaments.
> 
> For 5 pin tubes, the "isolated" pin is always #3.  If you count counterclockwise from #3, you will discover that the two pins FARTHEST from #3 are #1 and #5.
> 
> You need a tube manual or an old Handbook.
> 
> 73
> 
> Mike
> WA4DLF
>