On 7/18/2020 6:25 PM, Magnus Danielson wrote:
Hi,
A similar approach is used in the 10811 replacement oscillator setup for
the 5065, where a 7474 is used to divide 10 MHz to 5 MHz. Signal
conditioning consists of a DC-blocking cap and a pair of resistors to
bias the mid-point. The produced
Hi,
A similar approach is used in the 10811 replacement oscillator setup for
the 5065, where a 7474 is used to divide 10 MHz to 5 MHz. Signal
conditioning consists of a DC-blocking cap and a pair of resistors to
bias the mid-point. The produced noise is at least 10 dB worse than you
would expect.
Hi
One very simple “fix” for the low voltage sine wave:
Put in an L network and transform the load output to a higher
impedance. Voltage goes up as square root of impedance change.
For modest (2X ~ 4X) voltage changes, the lowpass L network still
has modest Q and low component sensitivities.
A long time ago I used a 74AC74 to prescale a 100MHz VCO down to 25, the
74AC74 was AC coupled to the VCO and the signal was a fraction of a volt.
Worked quite well.
Probably not time-nuts quality but in a pinch it did the job at the time.
Didier
On Sat, Jul 11, 2020 at 9:37 PM Alex Pummer
