[Lowfer] BCY

[Dale Rice]

Jerry,

I don't know what frequency you are starting with, but I have also built
things with the 4024 that didn't work . The 4024 is a fairly low speed
device and I had forgotten that. A selected 4024 or higher Vcc might help,
but what I have done is to go to the 74HC series for the divider so nothing
needed changing that I had already built.

Dale Rice


> Bill:
> I'm looking over different oscillator circuits and I did come across the
> MPF102 . I just might go that route . I did a breadboard prototype of
> the 4011/4024 circuit and for some reason it doesn't work, even did it
> twice with same result, the 4011 works well , but the 4024 isn't
> operating, even changed out the 4024 with no luck. I am using the 4024B,
> which should be a direct replacement for the 4024, or at least according
> to my references. I will have to tinker with it some more. The
> oscillator with be inside a building, however it isn't heated a great
deal.
>
> Jerry
>
> Bill Ashlock wrote:
>
> > Jerry,
> >
> > I used to find the 4011 stability fairly descent, although, as of
> > late, I've been starting out with a separate MPF102 xtal oscillator
> > because I have more control over the feedback capacities and bias
> > currents which can have an effect on the temp coefficient and the long
> > term stability.  Are you planning to keep the exciter inside the
> > house?...... highly recommended.
> >
> > Good luck!
> >
> > Bill A
> >
> >
> >> After checking the oscillators output on the exciter and found it not
> >> stable at all, I have decided to replace it. I obtained a schematic
> >> for the TM-1 transmitter and the model I have is different. The
> >> oscillator on the model I have uses three I/C's that are no longer
> >> available (or at least hard to find), but the schematic shows using a
> >> CMOS 4011 as the oscillator and a 4024 as a frequency divider. The
> >> circuit is very similar as shown in my 6th edition of the Low and
> >> Medium Frequency Radio Scrap Book.
> >> Has anyone here or is anyone here using this circuit on their LF or
> >> MF transmitters.? and how stable is it. or would you recommend a
> >> different oscillator circuit.
> >>
> >> Thanks
> >> Jerry