In fact I notice, now I am starting to completely wake up this
morning, in my link if you remove all the tuning components and
buffers, short the 330pF cap, and replace the inductor with a crystal
it becomes a standard crystal oscillator circuit used with the 'HCU04.
Seems to me it should work with the 'HC86 but there is always the
possibility of spurious oscillations with such buffered gates.

Steve VE3SMA

PaoloC wrote in message ...
Hi,
thanks to all those who replied and discussed this topic, providing me
with a lot of good suggestions.

I have built a few LC oscillators (VFOs) using a single gate of a
74HC04. Yes I know the 'HCU-4 should give less trouble, but I didn't
have any at the time. For an example, see

http://www.arsqrp.com/ars/images/bac...mages/Vfo1.gif

It should be possible to insert a crystal somewhere in the feedback
path to get a single-inverter crystal oscillator, though I have not
tried it. The key is that the tuned circuit is used to provide an
extra 180 degree phase shift.

Steve VE3SMA


PaoloC wrote in message ...
Hi,
thanks to all those who replied and discussed this topic, providing me
with a lot of good suggestions.

In fact I notice, now I am starting to completely wake up this
morning, in my link if you remove all the tuning components and
buffers, short the 330pF cap, and replace the inductor with a crystal
it becomes a standard crystal oscillator circuit used with the 'HCU04.
Seems to me it should work with the 'HC86 but there is always the
possibility of spurious oscillations with such buffered gates.

Steve VE3SMA

PaoloC wrote in message ...
Hi,
thanks to all those who replied and discussed this topic, providing me
with a lot of good suggestions.

Hi,
thanks to all those who replied and discussed this topic, providing me
with a lot of good suggestions.

In the end I might use a BJT/FET oscillator instead, especially if it
works with the ex-CB XTAL of my other post. Troubleshooting with a
receiver and a DVM is fun, but time consuming and often demotivating.

I dream of an oscilloscope as much as I dream of an HF dipole up on the
roof. Hopefully both will come with time, as well as children, a better
wage, ... ;-)

73,
Paolo IK1ZYW

I have a working 74HC14 oscillator:
"One gate of a 74HC14. 470ohm resistor from gate output to the parallel
of 1Mohm//XTAL. 10pF and 33pF (from the junkbox) capacitors to ground on
each side of the XTAL."

I have successfully made a circuit using a single gate of the 74HC86 similar
to you describe. I used 1K from the gate output to the 10MHz crystal. 12p
capacitor on either side of the crystal to ground. It works very nicely! See
the circuit diagram he
http://www.hanssummers.com/radio/qrs...mod2/index.htm .

73 de Hans G0UPL
http://www.HansSummers.com

I have a working 74HC14 oscillator:
"One gate of a 74HC14. 470ohm resistor from gate output to the parallel
of 1Mohm//XTAL. 10pF and 33pF (from the junkbox) capacitors to ground on
each side of the XTAL."

I have successfully made a circuit using a single gate of the 74HC86 similar
to you describe. I used 1K from the gate output to the 10MHz crystal. 12p
capacitor on either side of the crystal to ground. It works very nicely! See
the circuit diagram he
http://www.hanssummers.com/radio/qrs...mod2/index.htm .

73 de Hans G0UPL
http://www.HansSummers.com