avr300 said:Couldn't think when I was asking, sorry. It's a "of cause", it gives no meaning terminating a 18M wavelength after just 5mm.
i think we have all thought of it.
does make you wonder about the coax between dac and decoder
or the coax connectors for the tranport cable?
allan
ps more various calculators
http://www.audioscientific.com/Auto Calculators & References Links.htm
Hi guys,
Just for the record: the wave we are talking about is a square wave, with lots of higher order harmonics, that have much shorter wavelengths. Also the velocity in a cable is not light-speed, but less.
The point: the actual wavelength is about 20x? shorter than it seems at first glance. Not an issue here, just putting things into perspective. Am i being too much on the details?
.
Regards,
Ray.
Just for the record: the wave we are talking about is a square wave, with lots of higher order harmonics, that have much shorter wavelengths. Also the velocity in a cable is not light-speed, but less.
The point: the actual wavelength is about 20x? shorter than it seems at first glance. Not an issue here, just putting things into perspective. Am i being too much on the details?
.Regards,
Ray.
No no, its fine Ray. But I don't measure the waveform out of the Tent XO near square. I don't know whether my scope is the limit, but this is what I get from it. Doesn't seem to be a comperator output.
But I do agree, the square wave has much more energy than the sine.
/avr300
But I do agree, the square wave has much more energy than the sine.
/avr300
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avr300 said:
Hi avr,
Same as Allan, the square looks like a sine on my scope. If you do a search on this topic you can find more about it, and how to do a proper measurement with a terminated cable.
The closest I got to a square was on the scope of a friend of mine:
Ray.
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Hi,
Not sure you need to square up the sine...
A simple Colpitts FET oscillator should do it.
http://www.diyaudio.com/forums/showthread.php?postid=886328#post886328
http://www.diyaudio.com/forums/showthread.php?postid=891879#post891879
Not sure you need to square up the sine...
A simple Colpitts FET oscillator should do it.
http://www.diyaudio.com/forums/showthread.php?postid=886328#post886328
http://www.diyaudio.com/forums/showthread.php?postid=891879#post891879
6h5c said:
That's true ash,
When I pull the AD8561 out of it's socket and replace it by a 10n coupling cap, everything runs fine. Haven't done any A-B comparing yet though, could be worth to try. It would sure make the clock a lot cheaper
Ray.
Ray,
Without the comparator...
I'm not too sure how we should power the oscillator.
Would you know how to calculate the power supply consumption of the oscillator?
ash_dac said:
Ray,
Without the comparator...
I'm not too sure how we should power the oscillator.
Would you know how to calculate the power supply consumption of the oscillator?
Use a TL431/BC550 as in the KwakClock.
Check the output of Jocko's clock - no comparator!
The arrangement workswell. I have used a similar circuit on the back of a simple colpitts oscillator, in a couple of CD63's.
Andy
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6h5c said:
terminated cable will give more or less square wave but it's still distorted.
if i am looking for a problem with the clock signal, i get a distorted
signal.
question is.
Is the clock signal distorted or the terminated circuit to clean up the distorted signal.
my head hurts
I was looking for a similar signal in and out of devices
(like using a logic probe--- there, not there or there at the wrong time
)allan
avr300
ray or andy, 1volt ac signal?
ash_dac said:Ray,
Without the comparator...
I'm not too sure how we should power the oscillator.
Would you know how to calculate the power supply consumption of the oscillator?
That's not too difficult. The offset voltage across the FET's 1k source resistor is about 2.5V, so that would mean 2.5mA. It wouldn't hurt to load the output of the PSU with an extra 1k in this case, to ensure minimum current draw.
poynton said:
I would prefer the more passive approach, with a pre-regulator, like this circuit that Guido uses for his XO-module. That's one potentially noisy TL431 less to worry about. Output is a little over 5V with these resistor values, and that will result in a nice 5Vpp sine wave.
Ray.
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awpagan said:terminated cable will give more or less square wave but it's still distorted.
if i am looking for a problem with the clock signal, i get a distorted
signal. question is.
Is the clock signal distorted or the terminated circuit to clean up the distorted signal. my head hurts
allan
avr300
ray or andy, 1volt ac signal?
Hi Allan,
The more capacitive load you put on the square wave output, the more sinusoidal it becomes. The cable acts as a low-pass filter between the signal and the scope, and filters out all the higher harmonics. If you load the output as little as possible, you'll get a square more or less. Also the amplitude of the signal gets less the more you load it. The scope picture I posted was measured with a decent 10x probe, and still shows a lovely 5Vpp output.
Ray.
I read somewhere else on this forum some issues with an ad826 opamp (i've ordered one), this opamp went in oscilation in a certain cd player (no marantz).
When i'm gonna put an AD826 in de my 67se is there a risk that this happens also on my 67se?
How can I prevent this? Puttting a capacitor between pin 4 and 8 on the opamp?
When i'm gonna put an AD826 in de my 67se is there a risk that this happens also on my 67se?
How can I prevent this? Puttting a capacitor between pin 4 and 8 on the opamp?