[R-390] Tube List For R-390 (non A)

[Norman Ryan]

Hi, all,

Here is a list of the tubes in the R-390 (non A) taken from TM-856 plus
some hints on substituting 12AU7s:
 
V201 6AJ5
V202 6BJ6
V203 6C4
V204 6C4
V205 6C4
 
V401 6AJ5
V402 6AJ5
 
V501 6BJ6
V502 6BJ6
V503 6BJ6
V504 6BJ6
V505 6BJ6
V506 6AK6
V507 12AU7
V508 5749/6BA6W
V509 6BJ6
V510 12AU7
V511 12AU7
RT512 3TF7 (ballast)
 
V601 12AU7
V602 12AU7
V603 6AK6
V604 6AK6
V605 6082
V606 6082
V607 6BH6
V608 5651
V609 5651
 
V701 5749/6BA6W
 
V801 26Z5W
V802 26Z5W
 
V901 12AU7
V902 12AU7


Substituting the 12AU7 with 5814A:
The 12AU7 can be substituted in some cases with the 5814A.  Be aware
that its filament current draw is slightly higher than for the 12AU7; i.
e., 150 ma (12AU7) versus 175 ma (5814A).  This will pose a problem for
the R-390 because most of the tubes filaments are wired in series off
the 26.5 VAC.

You can substitute 12AU7s where they are not wired in series with
another type tube as long as you replace BOTH 12AU7s with 5814As.  Here
is the list of the series filament circuits in the R-390 (non A):

V202   V203   V204   V205
6BJ6   6C4    6C4    6C4
 
V401   V402   V201
6AJ5   6AJ5   6AJ5   (Only three tubes here @ 18.9 VAC plus four chokes
wired in series.)
 
V501   V502   V503   V504
6BJ6   6BJ6   6BJ6   6BJ6
 
V505   V506   V511
6BJ6   6AK6   12AU7
 
V507   V510
12AU7  12AU7  <---  OK to use pairs of 5814As.
 
RT512  V508   V701
3TF7   5749   5749
 
V601   V602
12AU7  12AT7
 
V603   V604   V607   V509
6AK6   6AK6   6BH6   6BJ6
 
V901   V902
12AU7  12AU7  <---  OK to use pairs of 5814As.

Each row represents a filament series circuit.  The 12AU7 in V511 should
not be substituted with the 5814A as the latter's filament voltage will
drop and voltage will increase across V505 (6BJ6) and V506 (6AK6).  V601
(12AU7) should not be substituted since V602 is a 12AT7.

The 12AU7s in V507 and V510 can be substituted, but use 5814As for
BOTH.  The same applies to V901 and V902.  These are the only instances
where the 5814A will work properly.

Whew!!  This was a lot of effort to get us back on topic.  :-)

73 de Norman KG4SWM