It would be helpful to give some specific info about the circuit and
regulators used for these experiments, such as operating voltage, load
current, and regulator type. I may have missed some points in the
discussion on this, but I think the following things are the case:
1. The circuit exhibi
Thanks, John!Just ordered two and looking forward to receiving it. 73,
Christopher de AI6KG
On Wed, Dec 7, 2016 at 11:45 AM, John Ackermann N8UR wrote:
> I'm happy to report that TAPR is now accepting orders for the TICC
> timestamping / time interval counter. We've placed an order with th
Hi
The problem with a “simple” filter is that they rarely work as well as you
might think
they do. Grounding and other layout issues generally get you sooner than you
would
think. Coils and caps are often not as broadband as you would hope….
Bob
> On Dec 8, 2016, at 12:34 AM, Hal Murray wrote
kb...@n1k.org said:
>> the cool thing about those parts is that their PSRR extends
>> up to several MHz. A lot of LDOs have good PSRR to kHz.
> Which to bring it back to noise in radios â¦.. could be the issue there. The
> device isnât oscillating, itâs just not blocking the crud from upstr
Hi
> On Dec 7, 2016, at 11:36 PM, jimlux wrote:
>
> On 12/7/16 4:20 PM, Scott Stobbe wrote:
>> Yes, the short hand I like to use is 4 nV*sqrt(R/1000).
>>
>> 2 nV/rthz off a bandgap is pretty darn impressive, that includes a delta
>> vbe gained up ~10x.
>>
>> On Wed, Dec 7, 2016 at 7:03 PM Bob
On 12/7/16 4:20 PM, Scott Stobbe wrote:
Yes, the short hand I like to use is 4 nV*sqrt(R/1000).
2 nV/rthz off a bandgap is pretty darn impressive, that includes a delta
vbe gained up ~10x.
On Wed, Dec 7, 2016 at 7:03 PM Bob Camp wrote:
H
the cool thing about those parts is that their PSRR
On 12/07/2016 08:57 PM, Mark Sims wrote:
The files should wind up in your heather directory. Type in ? at the keyboard, scroll
down to the end of the command line help info and there should be a line that says
"put heather.cfg in directory " The actual directory depends upon the
opera
Yes, the very low frequency noise of these regulators isn't anywhere near as
impressive as their high frequency noise.However for some RF circuits the low
frequency power supply noise may not be as significant as other effects.
Bruce
On Thursday, 8 December 2016 2:59 PM, Gerhard Hoffmann
Am 08.12.2016 um 01:20 schrieb Scott Stobbe:
Yes, the short hand I like to use is 4 nV*sqrt(R/1000).
2 nV/rthz off a bandgap is pretty darn impressive, that includes a delta
vbe gained up ~10x.
Methinks the advantage comes from converting their reference (whatever
that may be)
to a really high
The files should wind up in your heather directory. Type in ? at the
keyboard, scroll down to the end of the command line help info and there
should be a line that says "put heather.cfg in directory " The actual
directory depends upon the operating system and how Heather was started.
T
Am 08.12.2016 um 00:50 schrieb jimlux:
On 12/7/16 3:32 PM, Richard (Rick) Karlquist wrote:
On 12/7/2016 12:16 PM, Clint Jay wrote:
I was looking for a low noise regulator to power a log amp/detector
earlier
this year and was rather surprised to find the 78xx regulators were
considerably better
For Windows 10, what is the file name for the Lady Heather dump
screen command? What folder is it in?
For the specified time (/nd=hh:mm:ss), is it GPS time or system
time?
I want to capture the precision survey plot without using
Windows Print Screen; my Lady Heather screen resolution is
Hi
At the often quoted 1.5 ns / meter error level, that would be almost 3.5 ns. At
the “worst case” 3 ns / meter
you would almost get to 7 ns.
Bob
> On Dec 7, 2016, at 7:17 PM, Mark Sims wrote:
>
> It depends upon your lat and lon, but figure about 10 feet. Basically
> earth circumferen
Yes, the short hand I like to use is 4 nV*sqrt(R/1000).
2 nV/rthz off a bandgap is pretty darn impressive, that includes a delta
vbe gained up ~10x.
On Wed, Dec 7, 2016 at 7:03 PM Bob Camp wrote:
> Hi
>
>
>
> Just for reference, KTB in 1 Hz at 50 ohms is roughly 0.9 nV at room
>
> temperature.
It depends upon your lat and lon, but figure about 10 feet. Basically earth
circumference is 24,000 miles * 5280 feet per mile divided by (2**24) (bits in
the sign+significand of a 32 bit float). The math works out to 7.5 feet, but
one always has to pay some imprecise math tax...
One can s
I've no doubt there are many excellent low noise regulators out there that
are orders of magnitude better than the 78xx series, but there are also
many that claim low noise as a headline feature and are actually worse
when you dig into the specification.
On 7 Dec 2016 23:42, "Richard (Rick) Karl
Hi
Just for reference, KTB in 1 Hz at 50 ohms is roughly 0.9 nV at room
temperature. The previously mentioned 2 nV is equivalent to about 250 ohms.
Bob
> On Dec 7, 2016, at 6:58 PM, Scott Stobbe wrote:
>
> You can buy opamps off the shelf with an input referred noise less than a
> 50 ohm resi
You can buy opamps off the shelf with an input referred noise less than a
50 ohm resistor to build up a preamp (of course you can build up something
even lower with discretes, but then it's a time commitment over a basic
opamp preamp)
Even if your regulator is low noise if it's running with low ph
Hi
You can indeed find regulators with noise densities that work out to be
uV/sqrt(Hz) advertised as
“low noise”. Who knows how marketing justified making the claim other than “not
as totally rotten
as our older part”.
Bob
> On Dec 7, 2016, at 6:32 PM, Richard (Rick) Karlquist
> wrote:
>
>
On 12/7/16 3:32 PM, Richard (Rick) Karlquist wrote:
On 12/7/2016 12:16 PM, Clint Jay wrote:
I was looking for a low noise regulator to power a log amp/detector
earlier
this year and was rather surprised to find the 78xx regulators were
considerably better than many of the "low noise" devices.
On 12/7/2016 12:16 PM, Clint Jay wrote:
I was looking for a low noise regulator to power a log amp/detector earlier
this year and was rather surprised to find the 78xx regulators were
considerably better than many of the "low noise" devices.
Are you kidding me? Check out the Linear Technology
On 12/7/2016 5:49 PM, Artek Manuals wrote:
All the talk a few weeks ago about the 5370B reminded me I have an
original Operating & Service manual for the beast.
This is a slightly earlier manual for serial prefix 2313A ( with no
change pages) # 05390-90020. Pages are no longer glued in the b
So some more specific detail in how I am running LH with multiple TBs. I am
actually running three instances of LH all with unique command line input for
each TB and each with a different COM port specified. The three TBs are running
from the same antenna using a Symmetricom 5853A 4-way splitter
ch...@chriscaudle.org said:
> Mark has explained previously on the list, but it is actually kind of
> convoluted. The command to set the position does not accept enough numeric
> precision to accurately set the position which was determined from
> long term averaging...
What does the chop-off t
All the talk a few weeks ago about the 5370B reminded me I have an
original Operating & Service manual for the beast.
This is a slightly earlier manual for serial prefix 2313A ( with no
change pages) # 05390-90020. Pages are no longer glued in the binding so
it you will need a 3 ring binder b
I don't think so. I first ran into a batch of LM340-5's
that were excellent oscillators back in the 1970's... long
before counterfeiting was even remotely possible.
The symptom is the regulator puts out only 4.5 out of 5V.
LM309's were, however, totally immune.
Usually, I had to be really bad t
Hi
There are a *bunch* of people making stuff like 78xx regulators. Even
20 years ago, there was a lot of difference between brand M, brand T,
and brand F on these devices. Today the spread is even larger. Toss in
outfits that sub contract the work to who knows where this week ….
What you get t
I was looking for a low noise regulator to power a log amp/detector earlier
this year and was rather surprised to find the 78xx regulators were
considerably better than many of the "low noise" devices.
But!!
I've also had odd experiences with some brands of 78xx devices (and way
before the 'net w
No, the SL keyboard command on TSIP receivers should do the
"multiple-single-point-surveys-until-it-gets-close" thing to set the
lat/lon/alt to better than single precision floating point accuracy. .
The advantage of doing a full 48-hour survey is that the surveyed position was
calculated by th
Lady Heather can only talk to one device at a time, but you can fire up
multiple copies of Lady Heather to control multiple devices. You would need to
specify a different serial port to use on the second instance's command line.
Version 5.0 will let you swap serial ports and receiver type on
Could the low noise parts actually be counterfeit, relabeled as such?
Is the circuit the regulator feeds sensitive to a narrow band of voltage
that the "good regulator" is outside of?
Try replacing the regulator with a battery supply and resistor divider
to attain the working voltage. Move th
I replaced the original caps, and I added caps, I substituted good Jonhansen RF
caps, and Tanceram caps.
No help at all.
The layout and routing is as good as I could do, and the only improvement I
could see possible would be to move one cap closer to the reg.
The difference would be less than
So need to do two long surveys then - what a pain ...
Oh well
Dave
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Caudle
Sent: 07 December 2016 19:54
To: time-nuts@febo.com
Subject: Re: [time-nuts] Question on LH
On Wed, December 7, 2016 12:51 p
On Wed, December 7, 2016 12:51 pm, David C. Partridge wrote:
> But in any case at the end of the LH 48 hr survey, the survey location
> will be stored into the currently connected TB. If both TBs are connected
> to the same antenna, I think you'll need manually to set the location of
> the second
The probes don't seem to affect anything.
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Andy
Sent: Wednesday, December 7, 2016 7:56 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Totally unrelated, but..
>
> I loo
I'm confused here, LH can be connected to only one TB at any one time
(depending on command line options).
But in any case at the end of the LH 48 hr survey, the survey location will be
stored into the currently connected TB. If both TBs are connected to the same
antenna, I think you'll need m
Hi
Usually what happens is you have a broadband oscillation at 3.5 to 4 GHz (based
on your 3 GHz
upper limit). The “munge” mixes with this and that creating interference at RF.
Bob
> On Dec 7, 2016, at 1:28 PM, Van Horn, David
> wrote:
>
> Well so far at least #3 is not true.
>
> It may be
Once upon the time, there were some "three legged" voltage regulators,
which were very sensitive to the ESR value of the capacitor which was
connected to their output. With to low ESR values they oscillated, [the
oscillation was "inside" of the regulator, which became warm, or
sometimes hot, be
Well so far at least #3 is not true.
It may be something happening below the noise floor or outside the bandwidth,
but I was looking from 0-5MHz.
I have 3Ghz+ available, but I wouldn't expect these parts to be that fast.
It's a mystery, but I love solving mysteries.
-Original Message-
F
I'm using the latest version of LH connected to two Thunderbolts. Whenever I
do a precision 48-hour antenna survey, I'm confused on if the derived best
coordinates are automatically loaded into the Lat & Lon registers when it
completes. What is the procedure at the completion of the precision surve
Remember that the internal Voltage reference in the original three terminal
regulator designs is a Zener.
(Zeners are also useful as RF white noise sources.)
The regulator is generally an amplifier with DC feedback.
If you look at the application notes on the early regulators, they require
capacito
Hi
You probably have proven one of the most basic design truths: Parts will
*always* oscillate just
outside the bandwidth of your test gear” :). A few other possible issues:
1) Something else is oscillating and it is simply interacting with the
regulator in an odd way.
2) The oscillation / noi
>
> I looked at the reg input and output with scope and spectrum analyzer, and
> I don't see anything that indicates excessive noise or oscillation.
>
Does the receiver's noise persist with the scope or spectrum analyzer
attached? Connecting their probes might temporarily "fix" the problem so
tha
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Is part of the problem that the level of noise that is of concern is
below what a scope can see anyway: PPB? If the noise is not narrow
band it might also be not observable using a spectrum analyzer?
Pete.
On 12/7/2016 4:09 AM, Poul-Henning Kamp wrote:
In message , "Van Horn, David
In message , "Van Horn, David" writes:
>So what is it that a monolithic regulator (linear) can do which
>is not observable on a scope or SA, which would cause a receiver
>to think it's getting a signal or significant noise in band?
You have to pay really good attention to specs on some l
46 matches
Mail list logo
