[Lowfer] Beacon Schematic

[John Hamer]

Kasey,

John is correct about the resistor. I did not mean to omit that.

John,  thanks for linking those messages. I was trying to find them earlier
to show Kasey, but was having trouble.

Regards,
John Hamer
Lowfer JH


On Mon, Nov 23, 2020, 10:23 PM KA4SEY <ka4sey at gmail.com> wrote:

> John D.
>
> John H. has helped me out a lot so I'm hopefully on a good path. With me
> building a new transmitter with all the new things I have learned it should
> do well. I will still leave room for a LPF just in case but like you said
> with the high Q factor it should be fine without one. I'm still very new so
> any information is helpful. Thanks again
>
> Kasey
>
> On Mon, Nov 23, 2020, 10:16 PM J D <listread at lwca.org> wrote:
>
> > Kasey, I'd really recommend not omitting the 2.2 - 10 meg resistor
> > between pins 10 and 11 of the 4060, and the series 1 - 1.8 K resistor
> > between pin 10 and the crystal. Sometimes it'll work without them, but
> > other times there is unreliable startup or instability to struggle with
> >
> > Other than that, I thoroughly endorse John H.'s recommendations,
> > particularly the output coupling arrangement and isolation of the tuning
> > coil from ground losses. His experiences with those issues are
> > documented in our discussions of that topic on the LWCA Message Board
> > last December and January. You can find them in these archives,
> > particularly the one for January:
> >
> > https://lwca.net/mbarchiv/msg1219.htm
> > https://lwca.net/mbarchiv/msg0120.htm
> >
> > The high-Q tank circuit formed by the properly tuned inductor (that's
> > where an RF current meter will help) and the antenna capacitance is
> > normally more than adequate to comply with harmonic and spurious
> > emission limits for Part 15 operation at 1750 meters.
> >
> > I would include provision on your circuit board to add the LPF
> > components later, just in case (1) you find harmonics are a problem, and
> > (2) you are able to actually measure the impedance of the antenna system
> > and adjust the LPF values to match. But otherwise, the filter is likely
> > to result in more problems than benefits.
> >
> > 73
> > John Davis
> >
> > ______________________________________________________________
> > Lowfer mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/lowfer
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:Lowfer at mailman.qth.net
> > Post must be less than 50KB total for message plus attachment!
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> >
> ______________________________________________________________
> Lowfer mailing list
> Home: http://mailman.qth.net/mailman/listinfo/lowfer
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Lowfer at mailman.qth.net
> Post must be less than 50KB total for message plus attachment!
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>