Building a 1KHz Clock Signal Timer using a 555

[Winzer]

I need to build a timer(using a 555) with a frequency of about 1KHz and a duty cycle of about 25% to provide my clock signal. So the 555 is obliviously in astable mode. From my engineering data sheet:
D=\frac{R_B}{R_A+2R_B}
f=\frac{1.44}{\left(R_A+2R_B\right)C}
where C is my capacitance value and the two R's my resistance values. This should be a strait forward calculation right?
then from the above equations
R_B=\frac{D 1.44}{C f}
andR_A=\frac{D 1.44}{C f}\left[\frac{1}{D}-2\right]
right?
I get R_B=36k\Omega and R_A=72k\Omega
This is a capacitance value of 0.01\mu F
Does this look correct?
Thanks

 

[Redbelly98]

Looks good.

72 kΩ isn't a standard resistor value, but you could just use two 36k's in series.

 

[dlgoff]

Or a potentiometer. You would be able to adjust out the tolerances from the other resistor and capacitor.