Jinx,

 FYI, some canned oscillators use the 4th pin for a tristate signal.
 So, you now have pin 14(8) as +5V, Pin 7(4) as Ground, Pin 8(5) as
 Output and Pin 1(1) as O/P enable.  Chances are the ones you have
 are not the tristatable type, but you never know.

                                            Regards,

                                              Jim



On Thu, 27 July 2000, "Thomas C. Sefranek" wrote:

>
> Jinx wrote:
>
> > I was trying to knock up an external clock for the PIC. I say "was"
> > because every single can I tried, 8-pin base and 14-pin base, gave
> > a less than useful output. I've a selection of 30 from 4MHz to 50MHz,
> > mostly carefully salvaged from old PCs and a couple of new 10MHz
> > ones as well. Connection seems to be simple enough 0V, +5 and
> > o/p. AKAIK none use the fourth pin functions, I think they may be a
> > bit old, but I tried anyway. None give anywhere near a full logic swing,
> > most < 1Vpp and the best only +0.8 to +2, which isn't enough to use a
> > buffer gate. Looked up circuits using them and pdfs from Toyocom and
> > Kyosera but can't for the life of me see what the problem is. As per test
> > circuits, can supply is regulated and decoupled and a 15pF test load,
> > which seems to make no difference. Any suggestions ? I can't believe
> > all 30 are hopelessly stuffed. Well, not yet. I haven't had a chance to get
> > them in-circuit and do evil things to them.
> >
> > TIA
> >
> > --
> > http://www.piclist.com hint: The PICList is archived three different
> > ways.  See http://www.piclist.com/#archives for details.
>
> I ONLY dirve my PIC with 4 pin oscillators and have had NO problems.
> The signal output is a full 0 to 5 volts.
>
> Could you be trying to drive an output pin?
> Or a mis-configured Oscillator option?
>
> --
>   *
>   |  __O    Thomas C. Sefranek  tcs@cmcorp.com
>   |_-\<,_   Amateur Radio Operator: WA1RHP
>   (*)/ (*)  Bicycle mobile on 145.41, 448.625 MHz
>
> ARRL Instructor, Technical Specialist, VE Contact.
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>
> --
> http://www.piclist.com hint: The PICList is archived three different
> ways.  See http://www.piclist.com/#archives for details.

jim@jpes.com

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http://www.piclist.com hint: The PICList is archived three different
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