I will mention that TI has a neural net chip/eval board now for as I recall
$99.
Like so many things maybe it makes sense.
Regards
Paul
WB8TSL
On Tue, Jul 9, 2019 at 11:02 PM Chase Turner wrote:
> Hi Glen,
>
> This is actually something I know a little about.
>
> Neural nets are most useful for
Has anyone tried to use a Neural net to control oven tmep, rather than
the ye olde PID ?
IE the algorithm learns from previous beheviour and successfully
predicts behaviour (or not).
I'm sure there are a few out there proficient with machine learning
algorithms.
Might make a good masters
Hi
TCXO’s are very different beasts than OCXO’s. In an OCXO, the crystal is not
exposed
to any significant temperature change.
Bob
> On Jul 9, 2019, at 8:05 PM, Mark Goldberg wrote:
>
> That is the dirty little secret of crystals. Manufacturers will test the
> temperature response in one
Thank you for the experience / instruction!
Em ter, 9 de jul de 2019 12:05, escreveu:
> Luiz,
> Ch1-75 Hydrogen storage details.
> “The compound LaNi5H, is used for storing molecular hydrogen.
> The LaHi5H, is characterized by high hydrogen partial pressure (2 to 5
> atmospheres) at +(20-50)
I've seen questions here about GPSDO disciplined frequency sources for =
odd frequencies. I recommend the RFZero: http://www.rfzero.net. For
$60 US or so, this unit will provide same. Is programmed using the
Arduino IDE, several examples provided. All that's needed is a UBLOX
compatible patch
That is the dirty little secret of crystals. Manufacturers will test the
temperature response in one direction, but if you heat and then cool
crystals and measure the frequency, they do exhibit significant hysteresis.
I've not been able to get a supplier of TCXOs for me to characterize this
as I
Hi
Well, if you ever get back into it:
You play games with varicap diodes to straighten out the curve. You may bias
them, you might
put them in parallel, you might put a coil or a cap across them. You can get
the curve plenty flat
enough for a control loop.
Hopping / discrete steps
Forrest,
Thanks very much for the extensive comments, they're greatly helpful.
I thought I might say a little more about my goals, and add some notes
on points that you made.
As mentioned, my main focus at this point is measurement of HF radio
signals, with a goal of 1 millihertz accuracy.
and non monitonicity in the device is the death of a control loops.
My attempts at building good OCXOs using cheap AT crystals in the 90s
was thwarted by non monotonic bending crystals !
And everytime they would wake up, the monitonicity would be in a
different part of the control
HI
Actually a monotonous ( = un-exciting) GPSDO is a *really* good thing :) Having
one that
does exciting stuff from time to time is *not* at all what you are after :)
Now we get to find out what auto spell check did to all of that …...
Bob
> On Jul 9, 2019, at 3:57 PM, David G. McGaw
>
Leo -
I do believe you mean non-monotonic, rather than non-monotonous. Not
being monotonous is a good thing. :-)
David N1HAC
On 7/9/19 1:20 PM, Leo Bodnar wrote:
> It's not very good, it is highly non-linear and even worse - nonmonotonous.
> It sometimes produces runt pulse glitches when you
It's not very good, it is highly non-linear and even worse - nonmonotonous.
It sometimes produces runt pulse glitches when you roll time backwards.
I have used them in GPS clocks for many years but never enabled them for end
user mode.
It's really a very primitive delay line series and I don't
RobertThat was my wrong take, since as long as I have messed with timing GPS
receivers the difference was price and the fact that saw tooth data was present
in hardware. Juerg did his first M12/Dallas/Maxim in 2004 driving a PRS 10
only replacing it when he bought a Tbolt through TARP.Working
In message <8e74832c-58e6-c2ef-f68c-48e116718...@leapsecond.com>, Tom Van Baak
writes:
>The plot is beautiful. The reason this delay line technique isn't used
>much anymore is that AFAIK the Dallas chips are no longer produced. So
>almost every uses s/w sawtooth correction now.
So...
On Tue, July 9, 2019 10:50 am, Tom Van Baak wrote:
> chip. Look carefully and see the DS1023-50, which is an 8-bit
> programmable delay line (~0 to ~127 ns in 0.5 ns steps).
...
> The reason this delay line technique isn't used
> much anymore is that AFAIK the Dallas chips are no longer produced.
Let's put the Bert vs. Dana misunderstanding aside.
To me the key feature in Bert's photo is the Dallas/Maxim digital delay
chip. Look carefully and see the DS1023-50, which is an 8-bit
programmable delay line (~0 to ~127 ns in 0.5 ns steps). This is a
technique used to remove sawtooth error
Bert,
My take on the issue is that Mark Sims had not seen manufacturer documentation
on how specifically to use the sawtooth correction value. You posted a picture
of what we now know was an implementation of a use of the correction value. Did
you have manufacturer documentation on how the
Luiz,
Ch1-75 Hydrogen storage details.
The compound LaNi5H, is used for storing molecular hydrogen.
The LaHi5H, is characterized by high hydrogen partial pressure (2 to 5
atmospheres) at +(20-50) degrees C.
250 grams of the compound contains 18 liters of hydrogen at normal
pressure.
It is
I wrote:
> I'm guessing there are some time nuts here who might be able
> to give me some pointers.
And there were! Thanks for the suggestions & comments.
Dana Whitlow wrote:
> in the absence of a PPS or other electrical output from your
> "computer", what is the nature of the time "output"?
On 7/8/19 8:33 PM, Hal Murray wrote:
jim...@earthlink.net said:
Free space propgation delay for 5500 m is 18.5 milliseconds - compared to
16.67 millisecond period of 60Hz. A velocity factor of about 90%
Neat. Thanks.
What's going on? I'm used to calculating the velocity from the
Dana
This was in response to Mark Sins " I don't think that I have ever seen what to
do with the sawtooth value
documented in any receiver documentation"I did this 4 years ago it, is a
sawtooth corrected ublox. First pass. Always do a follow on board but never
did any thing with it since
In message <20190709053037.2d244406...@ip-64-139-1-69.sjc.megapath.net>, Hal Mu
rray writes:
>What's the advantage of a PSRR in the MHz range? Is it as simple as reducing
>the number and size of the caps needed?
The caps have only ever acted as a low-pass filter, to move the
noise
Um, you're quite right that DC lines have no phase angle - unless you call a
polarity reversal a 180 degree shift.
I was referring to the phase angle of the AC side of an inverter with respect
to the average phase angle of the grid that it is connected to.
It behaves just like a synchronous
>> Not only are they low noise, but they have spectacularly good HF
>> rejection across the regulator up to 10s of MHz.
> In the 5071A, I wanted high bandwidth PSRR and stumbled across a designer's
> manual (HP internal document) for the MMS Modular Measurement System. They
> described a
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