Quote:
Originally Posted by Jarvamundo
I'll look into frequency stability problems... i must say i don't seem to share this issue... but a technical explanation is required.... of course.
best & thanks for great questions.
Alex
|
That is because you didn't build one ... try it and you will see what I mean.
BTW, 555 is far from being stable enough either (1% over very tight voltage power supply range as best result). Hardly a time keeping circuit.
The only simple oscillator frequency controlled element that comes closer to pulsar (in terms of frequency stability) is quartz crystal resonator.... and it is essentially a MECHANICAL device
http://en.wikipedia.org/wiki/Crystal_oscillator
It can be used to build oscillators with =<0.01ppm accuracy/stability... still far away from pulsar's (10^-8, compared to pulsar's observed stability being better than 6 x 10^-14))
The next best thing is rubidium standard:
http://en.wikipedia.org/wiki/Rubidium_standard
And so on.
However, the relaxation oscillator model we are discussing here, albeit being interesting as an alternative speculation as a first preliminary candidate, if considered in more details from astrophysical aspect, can't explain the observed behaviour of pulsars.
The first problems (not only issues..) encountered are as follows:
- power (how? from where? how the current is channelled (there are no isolated wires in space)? mind you, this is NOT a simple schematic of neon tube oscillator - it is an object the size of Earth-Moon system maximum).
- Capacitor (again.. where is it? formed from what? it must be very solid in terms of mechanical structure because the frequency of proposed circuit is linearly proportional to capacitor's value. The same applies for resistor (or current value.. it must be VERY stable over long time periods to explain fr. stability)
- discharge element ( discharge is very chaotic and hardly repeatable process... ) what is the mechanics (or physics) of it? Where is it located?
- subjectiveness to noise - any small disturbance (outside and/or inside) will be VERY detectable in frequency change or pulse phase shift.
Too many problems to account for only one single property of pulsars with this model..
Rotating compact object model, on the contrary, does fit the bill consistently, including majority of other things - but this is up to Carl and others to point out to you. I'm only RF electronics engineer and I am saying the relaxation oscillator model is totally inadequate to explain this aspect of pulsar's physics (frequency stability - 6 x 10^-14 at least over couple of months)..