[Heathkit] Heath SP-2717a power supply

[Rich Post]

Yep, check the zeners and diode(s) that supply the fixed negative voltage 
reference.   The 2717(a) was the last of the breed and used zeners and 
diodes in place of the rather hardy 6X4 and gas regulator tubes in the 
previous generations.  There is a pic of the three prior Heathkit models, 
all of which use nearly the same circuit.  It's at the bottom of this 
linked page.

<http://oak.cats.ohiou.edu/~postr/bapix/Kepco605.htm>

73 de Rich KB8TAD



At 11:33 AM 12/15/2009, Dave Merrill wrote:
>Dave,
>
>Take a look at the negative 300 volt circuit.  It's needed for the
>voltage divider that includes the B+ control to work properly.  If you
>need a copy of the manual, I have it as a PDF and could send it.
>
>/dave
>N9ZC
>
>On Mon, Dec 14, 2009 at 4:43 PM, Dave <w8qwdave at peoplepc.com> wrote:
> > I have one of these sypplies and while it works, I am having trouble 
> regulating the B+ high voltage.  I get 300vdc at the low end to 350vdc on 
> the high end, and can not vary the voltage otherwise. The 6L6GC tubes are 
> brand new and the 6AU6 tested more than ok.  The resistors all test 
> within a nominal tolerance. Anyone out there with a suggestion as to 
> where to look next?
> >
> > Dave, W8QW
>______________________________________________________________
>Heathkit mailing list
>Home: http://mailman.qth.net/mailman/listinfo/heathkit
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:Heathkit at mailman.qth.net
>
>List Administrator: Duane Fischer, W8DBF
>** For Assistance: dfischer at usol.com **
>
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html