[Drake] R7A service manual

[Dan Cotsirilos K9DTC]

Just so everyone knows the 78L24 is not discontinued by everyone. Mouser has 
plenty of them for about .32.


Dan K9DTC



----- Original Message ----- 
From: "Garey Barrell" <k4oah at mindspring.com>
To: "Drake" <drake at mailman.qth.net>
Sent: Friday, February 29, 2008 9:00 AM
Subject: Re: [Drake] R7A service manual


> Dennis -
>
> Thanks for the info.  Just goes to show...  Even a blind squirrel finds an 
> acorn once in a while, if ...   :-)
>
> I didn't see how there would be much of a market for a 24V regulator. 
> Wonder what they had in mind?
>
> 73, Garey - K4OAH
> Glen Allen, VA
>
> Drake 2-B, 4-B, C-Line & TR-4/C Service Supplement CDs
> <www.k4oah.com>
>
>
>
> Dennis Monticelli wrote:
>> My company manufactured both types and Garey guessed right.  The 24V
>> part became obsolete due to low demand and the adjustable 317 series
>> was the recommended replacement.  It's performance is a little better
>> to boot.
>>
>> Dennis AE6C
>>
>> On Thu, Feb 28, 2008 at 2:24 PM, Garey Barrell <k4oah at mindspring.com> 
>> wrote:
>>
>>> 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
>>>  >
>>>  >
>>>  >
>>>  ______________________________________________________________
>>>  Drake mailing list
>>>  Home: http://mailman.qth.net/mailman/listinfo/drake
>>>  Help: http://mailman.qth.net/mmfaq.html
>>>  Post: mailto:Drake at mailman.qth.net
>>>
>>>
>>
>>
>>
> ______________________________________________________________
> Drake mailing list
> Home: http://mailman.qth.net/mailman/listinfo/drake
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:Drake at mailman.qth.net