[Drake] R7A service manual

[Garey Barrell]

Dan -

My R-7 Service Manual Power Supply Board schematic, dated 12-80, shows 
the LM317LZ.  Since R1922 and R1923, which would NOT have been needed 
with the 78L24 IC, are the last two resistors on the board it certainly 
implies a production change.

The 78L24 was probably NOT an easy part to source, so they just went 
with a variable IC and two resistors.

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 4-B, C-Line & TR-4/C Service Supplement CDs
<www.k4oah.com>



Dan Cotsirilos K9DTC wrote:
> Does anyone have access to a R7A service manual? I only have a R7 that I can refer to. According to the R7 manual on the multi regulator board the one with the DC to DC is supposed to have a 78L24 regulator. The one that is on my board in that same place is a LM317Z?
>
> What I would like to know is this a 7A update or did someone put the wrong part in. thanks
>
>
> Dan K9DTC
>
>
>