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

Fri, 31 May 2002 00:43:00 -0700

Something looks fishy on this tube list.  Is there a model of the R-390 that
used the 26Z5W V801& V802? I don't have my manuals here-but my R-390 does
not have any.
Glen Galati         KA7BOJ
Tacoma, WA.
----- Original Message -----
From: Norman Ryan <[email protected]>
To: <[email protected]>
Cc: Spence Barton <[email protected]>; <[email protected]>
Sent: Thursday, May 30, 2002 7:13 PM
Subject: Re: [R-390] Tube List For R-390 (non A)


> 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
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