Jim,
On 02/07/2015 12:48 AM, Jim Lux wrote:
Only maximal codes have 2^n-1 states/periods. There are other
configurations with shorter periods. A particularly tricky thing is
that if the shift register in a maximal generator ever winds up as all
zeros (e.g. from a upset or bit flip), then the
Hal,
On 02/06/2015 09:42 PM, Hal Murray wrote:
mag...@rubidium.dyndns.org said:
The typical noise generator chips uses a PRNG based on DFFs and XOR
gate(s). A typical weakness is that the chain of DFFs is to short, causing
a relatively high rate of cycling, which hearable as a beating.
mag...@rubidium.dyndns.org said:
The typical noise generator chips uses a PRNG based on DFFs and XOR
gate(s). A typical weakness is that the chain of DFFs is to short, causing
a relatively high rate of cycling, which hearable as a beating. However, for
some uses, that is OK.
The buzzword
A further comment on design of pseudo random code
generators. At some point the code may enter the dreaded all
zeros state. This clocks a zero on the input stage through all stages
and the whole thing just stops. So a AND gate looking
at all stages in parallel is used
to detect the all zero
Several of the reciprocal counters (DC509, DC5010) Tektronix built for their
TM500/TM5000 test equipment mainframes use a National Semiconductor noise
generator chip to dither their reference clock. They do this mainly to handle
the case where the input freq and reference clock are very close.
The typical noise generator chips uses a PRNG based on DFFs and XOR
gate(s). A typical weakness is that the chain of DFFs is to short,
causing a relatively high rate of cycling, which hearable as a beating.
However, for some uses, that is OK.
Cheers,
Magnus
On 02/06/2015 07:16 PM, Mark Sims
mag...@rubidium.dyndns.org said:
The typical noise generator chips uses a PRNG based on DFFs and XOR
gate(s). A typical weakness is that the chain of DFFs is to short, causing
a relatively high rate of cycling, which hearable as a beating. However, for
some uses, that is OK.
The buzzword
On 2/6/15 12:42 PM, Hal Murray wrote:
mag...@rubidium.dyndns.org said:
The typical noise generator chips uses a PRNG based on DFFs and XOR
gate(s). A typical weakness is that the chain of DFFs is to short, causing
a relatively high rate of cycling, which hearable as a beating. However, for
Hi Attila,
On 02/06/2015 08:30 PM, Attila Kinali wrote:
On Fri, 06 Feb 2015 19:29:46 +0100
Magnus Danielson mag...@rubidium.se wrote:
Since then interpolation of single-shot events have been investigated,
and is now down to 200 fs in the best counter I know of (and have).
Which counter is
[mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus
Danielson
Sent: Wednesday, February 04, 2015 5:41 PM
To: time-nuts@febo.com
Cc: mag...@rubidium.se
Subject: Re: [time-nuts] T.I. questions
Joe,
The single-shot resolution of the Option 040 series input is 10 ns.
The T.I. interval option adds
Pulse width modulation.
Suppose the readings go like this:
6,5,5,5,5,5,5,5,5,5,6,5,5,5,5,5,5,5,5,6,5,5,5,5,5,5,5,5,5,5
you would be able to interpolate that result to be 5.1
If it went:
6,6,5,5,5,5,5,5,5,5,6,6,5,5,5,5,5,5,5,5,6,6,5,5,5,5,5,5,5,5
You would be able to interpolate that result
On Fri, 06 Feb 2015 19:29:46 +0100
Magnus Danielson mag...@rubidium.se wrote:
Since then interpolation of single-shot events have been investigated,
and is now down to 200 fs in the best counter I know of (and have).
Which counter is that? I'm only aware of an experimental TDC that does
-nuts-boun...@febo.com] On Behalf Of Magnus
Danielson
Sent: Wednesday, February 04, 2015 5:41 PM
To: time-nuts@febo.com
Cc: mag...@rubidium.se
Subject: Re: [time-nuts] T.I. questions
Joe,
The single-shot resolution of the Option 040 series input is 10 ns.
The T.I. interval option adds jitter
Oops, I missed a digit on that last email. it should be 10,000 s
average for 100 ps resolution.
Joe Gray
W5JG
On Wed, Feb 4, 2015 at 1:58 PM, Joseph Gray jg...@zianet.com wrote:
Sorry for the simple questions. Old hands can simply ignore this
message if it bothers you.
I have an HP 5328A
Sorry for the simple questions. Old hands can simply ignore this
message if it bothers you.
I have an HP 5328A that I have pieced together from broken units. As
soon as I make a ribbon cable for the GPIB card, I want to use it for
T.I. measurements. I know it isn't nearly as good as a 5370, but
Joe,
The single-shot resolution of the Option 040 series input is 10 ns.
The T.I. interval option adds jitter to make the averaging useful.
If your PPS was instead a burst or a clock, comparing it to your clock
would make more sense and you could use that higher resolution.
If I had a GPIB
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