David C. Partridge wrote:
Cough - the rubidium clock or oscillator does have an intrinsic frequency,
which is the rubidium hyperfine transition of 6 834 682 610.904 324 Hz, it's
just that the frequency generated by the transition in question isn't used
to DEFINE the second, so by definition, it
When the 5071A product line was sold to Symmetricom ~4 years ago,
the production manager and his team of 15 moved with the product.
The manager left Symmetricom a few years ago, and recently most
of the rest of the team left Symmetricom. The 5071A will now
be made on the east coast at the facilit
Bruce Griffiths wrote:
Only if the noise figure of the following amplifier is 4dB or so.
With no extra amplification is used one only needs a signal level of
+1dBm to achieve a phase noise floor of -178dBc/Hz if the output is
extracted through the crystal in such a way that the thermal noise
Don Collie jnr wrote:
I`m not sure that questions like these is welcome on this list, but here goes anyway :
1/ What are the the 10 sources of the most constant [invariant] frequencies
known to man, in order of decreacing constancy? Four immediately come to mind.
I vaguely remember reading t
For a simple crystal oscillator the two word answer might be "Leeson's model". That of course is a cop out since it clearly defines multiple things that contribute to phase noise.
Bob
And Leeson's model is basically the same as Edson's model, circa 1950
(Edson: Vacuum Tube Oscillators)
It is entirely possible that a 10544 could have excellent aging and beat
a 10811. The SC cut doesn't improve aging. The other "disadvantages"
of the 10544 in terms of electronics also don't affect aging. The
main advantage of the 10811 is that it is much better from a cold start
in an instrumen
Bob Camp wrote:
Hi
Tough to believe that HP worried a lot about SKU inflation back when they
did the 5370 :)
I'm assuming that the 5370 was a Santa Clara design. That would put the
counter designers down the hall from the oscillator factory. Unlikely that
there was a communications gap ab
Samuel DEMEULEMEESTER wrote:
Hi Rick,
My goal is not to design a killer prescaler useable for all applications,
but just to get the same specs than the original HP/Agilent prescaler board,
and why not a bit better. The original HP board is a very basic design :
4-stage of MMIC and a good-old M
What the 10811 production line did was to compare two 10811's
to each other by driving a high level mixer. Anzac AM-123
amplifiers were used to increase the output level of the 10811's.
You can homebrew the AM-123 if you read the patent and can
get a 2N5109/2N5943 type of transistor. Amplify the
We have a bunch of sweepers at work, and many of the them have
died and can't be fixed. The only way they can be repaired is
to cannibalize one to fix another, assuming they don't have
the same bad module. We have given away an 8510 to a school
and have others gathering dust.
Rick
jimlux wrote
Samuel DEMEULEMEESTER wrote:
Right now, the performance is really good up to 3.5 GHz :
50 MHz : -7 dB
100 MHZ : -15 dB
250 MHz : -26 dB
500 MHz : -30 dB
1 GHZ : -32 dB
2 GHz : -32 dB
3 GHz : -30 dB
The real deal on the performance of prescalers is the ability to count
noisy sources. If y
Hal Murray wrote:
Several years ago, I found a web site for a commercial place that made them
for museums. (I forget why I was looking for that sort of stuff.) You might
find interesting stuff/ideas via google but I didn't find a similar site with
a bit of searching.
The Museum of Scie
ulm...@vaxman.de wrote:
blinked. This problem was eventually solved by driving the LED with a discrete
transistor instead of a free 74AC14 gate and decoupling this driver with an
RC-combination.
CMOS logic gates have a totem pole output that is famous for "overlap"
where both transistors on b
Hi, I was the designer of the board, but I don't remember the
part number of the reference. I will try to consult my paper
schematic when I get a chance, if no one else can help you.
I do remember that I originally used some convenient reference
which seemed OK from the data sheet, but turned out
On 11/17/2014 5:54 PM, Bert Kehren via time-nuts wrote:
I ground one side of the tuning diode and use the 2 to 12 V as the external
OCXO for my FRK's along with increasing the time constant. I have not
verified it but I think removing the zener Voltage should also improve ADEV.
Bert Kehren
nstant over mil temperature ranges.
Mail_Attachment --
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Brooke Clarke
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Richard (Rick) Karlquist wrote:
On 11/17/2014 5:54 PM, Bert Kehren via time-nuts wrote:
I ground one sid
See:
http://newsoffice.mit.edu/2014/portable-atomic-clocks-1112
Any comments?
Rick Karlquist N6RK
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and follow the instruction
I did some checking around for low noise buffer amps earlier
this year. They needed to have 200 MHz bandwidth, so this
isn't directly applicable to 10 MHz. I also needed isolation.
About the only information in print is from the usual suspects
at NIST. They wrote a series of papers taking a fai
On 11/27/2014 7:07 AM, Tim Shoppa wrote:
For a hobbyist doing things a few at a time, what advantage is there to
buying RF transformers made by Mini-circuits etc., vs winding them using
commonly available ferrite cores/binocular cores?
If I needed to do a production run of 1000+ boards with ti
On 11/27/2014 9:09 AM, Tim Shoppa wrote:
On Thu, Nov 27, 2014 at 10:28 AM, Bob Camp wrote:
The main complaint is the difficulty of getting the correct cores. I seem
to have a few dozen bags of cores.
The mainline distributors (Allied, Newark, Mouser, etc.) have excellent
selection of Fai
On 11/27/2014 11:03 AM, Didier Juges wrote:
Another reason is reproducibility. If you or someone else wants
to reproduce your design, using a well defined and available
commercial part makes it much easier to achieve the same
performance, particularly for RF components.
Didier KO4BB
On 11/28/2014 10:08 AM, Dave M wrote:
Rick,
Thanks for the brief review of MiniCircuits stuff (I'm not connected
with them in any way except as a customer).
Since you've characterized some of their parts, perhaps you could help
answer a question that someone else posted, and one that I would li
On 11/28/2014 1:04 PM, Bob Camp wrote:
If you do need to run substantial current through a choke core, the larger
binocular cores with a half turn through them are a better choice.
Still useless for 20A (or even 2A) though …
Bob
The binocular cores come in several hole sizes.
All other t
On 11/30/2014 11:09 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:
I think I have a flaw in my understanding of this.
How can something like an SR620 measure the ADEV of an oscillator, if the
oscillator is of a similar or better than the reference fed into the SR620?
What HP did with th
On 12/1/2014 4:08 PM, Bob Camp wrote:
Others did a similar thing by simply taking production OCXO’s to the limit of
their EFC range. That let you do a coarse sort to find some number of “likely”
units. Next step was to pop a few of them open and short this or that out to
get a reasonable be
Please Gerhard, more details on your choke
(medium size red Amidon core & two 220 uH Siemens chokes).
Maybe I can use it for 160 meter antennas.
Your T1-1 measurements make sense according to
my experience with these things. The "-6"
series (T1-6, etc) has larger cores and should
withstand more
On 12/8/2014 4:53 PM, Bert Kehren via time-nuts wrote:
We solved that problem by attaching the regulators to the FRK back plate
which is with fan control is kept within 0.01C. We did not do it for that
purpose but found that we needed some more heat in order to keep the fan in an
optimum fan
hat really matters.
Bob
Mail_Attachment --
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html
Richard (Rick) Karlquist wrote:
On 12/8/2014 4:53 PM, Bert Kehren via time-nuts wrote:
We solved that
rnment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html
Richard (Rick) Karlquist wrote:
On 12/8/2014 4:53 PM, Bert Kehren via time-nuts wrote:
We solved that problem by attaching the regulators to the FRK back plate
which is with fan control is kept within 0.01C. We did not do it for
that
p
On 12/9/2014 1:30 PM, ed breya wrote:
buried zener for lowest noise - this eliminates all the low voltage
references and three-terminal etc regulators that use band-gap
references. The down side is that the good kind of reference ICs will
need a higher (like 10V and up) operating voltage than ma
On 12/9/2014 3:02 PM, Bob Camp wrote:
Here's an overnight ADEV plot against the new Cs of where we are in
the project. Red is ADEV. Green is the TIC. Blue is the output of the
GPSDO to Channel A and the Cs to Channel B of my 5335A measuring TI,
using the 1PPS from my GPSDO to trigger the
On 12/11/2014 4:20 PM, Bob Camp wrote:
Hi
Those OCXO’s were made to the spec’s of an OEM customer. The spec’s are owned
by that customer and can not be released without authorization from them.
Anybody who wants to stay in the business would be a bit crazy to release
somebody else’s intelec
We have DirecTV with some receivers standard
definition and others High Definition. The
delay is considerably greater on the HD version.
Even OTA HD is delayed considerably, as noted
if you try to listen to a football game on the
radio while watching. Sometimes you hear "touchdown"
before the ba
On 1/20/2015 7:59 AM, Martyn Smith wrote:
Hello,
I have both the HP3048A and Timepod Phase Noise test Sets.
I have two low noise 100 MHz PLL's. The 100 MHz output is locked to a
10 MHz reference input.
However, the 3048A won't achieve lock. The 100 MHz PLL's loop bandwidth
(about 0.2 Hz)
On 1/28/2015 11:28 AM, Charles Steinmetz wrote:
Gerhard wrote:
It is a different game when you want to notch away sub/harmonics.
One problem with using crystals as traps (notch filters) is that the
series resistance of a crystal is several orders of magnitude higher
than that of a good seri
On 1/29/2015 5:41 PM, Alexander Pummer wrote:
And the narrow notch for the harmonic is not required anyway, since the
fundamental is fare enough, therefore a high Q LC trap will work
better, also with the setting of the biasing af the active devices the
Alex KJ6UHN
When I designed the 5071A R
First of all, the oven oscillator option of the 53230
is no where near as stable in ADEV as a 10811 for example.
The counter itself is 1 or 2 orders of magnitude better
than the built in timebase. So don't waste your money
on the OCXO option when you, as a time nut, undoubtably
already own someth
The other big difference is that the 10811 uses
an SC cut crystal instead of an AT cut crystal.
From a cold start, the SC achieves a given stability
much faster than an AT cut. If you are just going
to run the oven continuously (likely mode for time
nuts), this isn't any big deal to you.
The rea
PM, Richard (Rick) Karlquist wrote:
The other big difference is that the 10811 uses
an SC cut crystal instead of an AT cut crystal.
I stand corrected.
Rick
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On 2/25/2015 4:32 AM, Attila Kinali wrote:
On Wed, 25 Feb 2015 10:16:58 +0100
Attila Kinali wrote:
Actually, you should put the temp sensor close to the heater, not the crystal.
The delay between the actuator (heater) and the feedback (temperature sensor)
defines the dead time. The presence
Before the Keysight split, there was an Agilent
museum at HQ in Santa Clara. It was packed full
of interesting old HP stuff and even had a part
time archivist. I'm now retired and don't know
what became of this museum in the split.
I feel I got out while the getting was good.
Rick Karlquist N6R
On 4/11/2015 5:01 AM, J. L. Trantham wrote:
Unless the design has been changed, the 10811 option
for the 53132 has poor short term stability and
degrades the performance of the 10811 by something
like an order of magnitude. I complained about
this when the counter first came out 25 years
ago but
On 4/12/2015 1:03 AM, Adrian Godwin wrote:
What caused that degradation ? I'm interested in dos/don'ts for best use of
a 10811.
I don't remember the details much after 25 years, but
basically they have a distribution amplifier that
allows for internal or external 10 MHz and what I
remember is
On 4/12/2015 2:22 PM, Magnus Danielson wrote:
Hi,
The buffer transistors has not AC-bypass of the emitter resistance, so
that the DC current becomes large and thus contributes flicker noise.
The comparator at the bottom isn't doing a beutifull work of squaring
things up without contributing n
On 4/12/2015 3:04 PM, Perry Sandeen via time-nuts wrote:
List,
For me it was simpler to buy asurplus HP 5087A for best offer which turned out
to be $300 delivered.
The 5087 series is ancient technology that has mediocre performance.
I remember looking at the circuit designs in the series
The 5071A doublers I designed use MCL ASK-1 mixers.
The LO and RF ports are connected in series. This
arrangement is self limiting. So you drive them
fairly hard and the output is level. The IF port needs
to see a DC short circuit of course. This was
essential in the 5071A since there were 5 d
On 4/12/2015 6:30 PM, Attila Kinali wrote:
It might be that I'm already too sleepy, but I don't see why
a faster comparator would add more jitter. Actually, my intuition
(which is clearly wrong) would say the contrary. So, which effect
does increase the jitter with comparator speed?
The fast
On 4/13/2015 3:11 AM, John Miles wrote:
A comparator with less open-loop gain was what they needed. Somebody at HP
really liked ECL line receivers, though. Those were very noisy at HF, but this
had little or nothing to do with their bandwidth (see my other post.)
To square up a 10 MHz sig
On 4/13/2015 12:14 PM, Magnus Danielson wrote:
Oh yes. Some people say that you should not overcomplex things. My
experience is that oversimplifying them can cause a long stretch of
complex problems and complex workarounds making the total solution more
expensive in development, customer relat
Perhaps it is not a good analogy, but I think of
the cesium beam tube in the 5071A. The plans
alone are very non-trivial. Then there are
a bunch of proprietary machining details that
I can't disclose, that are way beyond the
merely having access to a CNC tool. The
systematic error due to the CB
On 4/23/2015 7:17 AM, Alberto di Bene wrote:
On 4/23/2015 9:20 AM, VK2DAP wrote:
/1) Generally speaking, would it be correct to say that when a product
model number changes from A to B,//
//that represents an improvement or major update to a product?/
I remember having read (don't recall wh
On 4/23/2015 12:20 AM, VK2DAP wrote:
Dear time-nuts,
I have a question about the HP5328A and HP5328B universal counters.
1) Generally speaking, would it be correct to say that when a product model
number changes from A to B, that represents an improvement or major update to a
product?
2) I a
On 5/4/2015 5:25 PM, J. L. Trantham wrote:
Charles,
Thanks for the help. I need to learn how to add text to .PDF documents.
Go to:
www.tracker-software.com
and download (for free):
PDF-Xchange viewer.
Rick Karlquist N6RK
___
time-nuts mai
On 4/26/2015 3:51 AM, Bryan _ wrote:
All:
P
I was looking at the project from David partridges web site
http://www.perdrix.co.uk/FrequencyDivider/index.html
-=Bryan=-
___
This is a comparator based circu
On 5/6/2015 3:24 PM, Bob Camp wrote:
Hi
A standard input on a frequency counter is not a very demanding thing in the
hierarchy of
TimeNut signals. You can drive any of them with some pretty simple logic gate
based
circuits. No need to spend a lot of money.
Bob
Logic gate, yes. Comparat
On 5/8/2015 2:19 PM, Bob Camp wrote:
On May 7, 2015, at 11:09 AM, Attila Kinali wrote:
On Wed, 06 May 2015 18:09:03 -0700
"Richard (Rick) Karlquist" wrote:
A standard input on a frequency counter is not a very demanding thing in the
hierarchy of
TimeNut signals. You can dr
The only gates that seem to do very well are high speed (as in 74AC or faster)
silicon CMOS. You need to run them with a fairly clean supply and feed them
with a p-p input that matches the supply voltage. Other than that, not a lot
of magic. Are they ideal - surely not. Will they hit 2x10^-13 ADE
On 5/20/2015 11:22 AM, Magnus Danielson wrote:
The older HP counter manuals explained it very nicely too, as they
illustrated the slew-rate & amplitude noise to time-noise conversion.
What do amazes me is the fact that I've yet to see a counter input
channel which takes care to square up the
I used a CPLD in a 900 GHz (that's right 900 GHz) optical
sampling scope timebase. It was great because you just
write a 17 bit counter in VHDL and there it is. You
don't have to know anything about building digital
hardware any more (40 years of experience wasted).
Nobody cares about look ahead
Can someone explain to me how this is going to work in
light of the fact that each clock is in a different
gravitational field? Or is accuracy not the measurement,
but rather stability? No, that can't be because any
lab that wants to measure stability merely needs to build
two or three copies of
The counter only had to run at ~50 MHz, on account of our
mode locked laser ran at that frequency. I don't remember
what the CPLD was rated at.
Rick
On 6/5/2015 8:19 PM, Hal Murray wrote:
rich...@karlquist.com said:
I used a CPLD in a 900 GHz (that's right 900 GHz) optical sampling scope
tim
That's interesting. I worked for the HP Santa Clara Division
from 1979 until just before it was closed in 1998. I
forget who "invented" MDA at SCD, but it was hyped like
it was some new concept and I never heard anything about
the HP9540.
Many times someone would come to me and ask me about
som
On 6/17/2015 8:22 AM, Jim Lux wrote:
I'm looking for some representative data for inexpensive microwave VCOs
(in the 2.5-6 GHz range, in general). Not in a locked loop situation,
If the phase noise data you have goes to a low enough frequency to
get below the 1/f corner (which is the case fo
On 6/17/2015 8:22 AM, Jim Lux wrote:
I'm looking for some representative data for inexpensive microwave VCOs
(in the 2.5-6 GHz range, in general). Not in a locked loop situation,
If you are working up to 2.5 GHz, you can get a low power
chip for $2 from Analog Devices that has a VCO and syn
On 6/18/2015 1:20 PM, Magnus Danielson wrote:
The trick is to convert the 2nd degree loop to a 3rd degree loop, which
then allows for a 12 dB/oct slope, to counteract the 9 dB/oct slope.
No this is not correct. A very conventional Type 2 loop, where the
loop filter consists of an integrator w
On 6/17/2015 11:36 PM, Attila Kinali wrote:
Do you have any recomendation, where an ordinary engineer could
read up on this topic?
Attila Kinali
There is always Floyd Gardners, Phase Lock Techniques.
However, a better tutorial would be the one written by
HP's Dieter
On 6/20/2015 6:25 AM, Jim Lux wrote:
This makes a good case for the "30dB/decade very close in"
Somewhat had asked about "how" close in the 30 dB/decade is
good for. There is a reference about this issue. The
book Edson: Vacuum Tube Oscillators has what I believe is
the first published cal
On 6/20/2015 1:16 PM, Alex Pummer wrote:
Actually a YIG, even "standalone" has very good phase noise performance,
as long as the tuning current is quite, once upon the time HP made some
cheaper version of the 856x-es spectrum analyzers [ perhaps that was the
95xx ] they had the first LO just "sta
On 7/18/2015 2:16 AM, Attila Kinali wrote:
I always wonder how you figure out whether a transistor is low noise
or not. What part of the datasheet hints at which transistors have low
noise and which have not? Even if it's just try and measure, how
do you find good candidates to measure?
On 7/20/2015 8:12 AM, Charles Steinmetz wrote:
Rick wrote:
Base spreading resistance can be overcome
by using a sufficiently high source impedance
This sounds like the all-too-common noise figure fallacy (increasing
input impedance to get a lower NF). All this does is raise the source
impe
OTOH, the other cure for high base spreading resistance is
to simply parallel multiple devices. This avoids the bad
side effects you mention. The other key noise parameter
in a BJT is RF current gain, and this cannot be "cured"
by any circuit design tricks.
Rick Karlquist N6RK
On 7/23/2015 8:2
On 7/24/2015 11:58 AM, Brooke Clarke wrote:
Hi Charles:
Does hFE (DC) have much relevance to this? Would hfe (AC) be the
important one?
Only insofar as DC current gain is an upper bound on AC current gain.
If your operating frequency is less than f-sub-t divided by beta,
then DC current gai
There used to be a color at HP called "mint gray" FWIW.
Rick
On 8/13/2015 1:58 AM, tim...@timeok.it wrote:
I am interested in knowing the exact name or number of the colors used by HP
for the HP5065A front panels.
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The thermal fuse plugs into pin sockets. It cannot be
soldered for the obvious reason that the solder
would melt it...at 109 degrees as it is marked.
My suggestion would be to jumper it out of the circuit.
Rick Karlquist N6RK
On 10/19/2015 12:31 PM, Dimitri.p wrote:
How common is it to find un
The oscillator transistor and buffer amplifier are basically
the same as the HP 10811, except for the absence of mode
suppressors. The difference here is that the oscillator
self limits in the oscillator transistor, whereas the 10811
has ALC. The discontinuous operation of the transistor,
as exp
On 10/26/2015 9:15 PM, Bruce Griffiths wrote:
The 10811A ocxo uses an oscillator of this type albeit with a lower crystal
current, an overtone crystal. However the output stages spoil the PN
floor..Cascaded transformer coupled CB stages are somewhat quieter.
Bruce
That's right. Burgoon (10
On 10/27/2015 10:11 PM, Bruce Griffiths wrote:
The answer to this conundrum is surely that the equation for PN doesn't apply
directly in this case
for offset frequencies outside the crystal bandwidth.
The Crystal actually bandpass filters the signal and PN noise generated by
oscillator.
For of
On 10/28/2015 10:38 AM, Hal Murray wrote:
rich...@karlquist.com said:
The 2N5179 in the 10811 is selected for minimum beta and Ft at 20 mA, which
is the start up condition due to the ALC being at full gain. It has a
special HP part number, so you wouldn't know this just looking at the parts
li
Do you have a specific URL for "hacking oscillators"? I can't
find it on Rubiola's web site.
Rick
On 10/28/2015 1:32 PM, Gerhard Hoffmann wrote:
Am 28.10.2015 um 19:22 schrieb KA2WEU--- via time-nuts:
This oscillator seems to have been more a frequency standard then a noise
standard. Today's
Driscoll wrote a lot about oscillators over the years.
I couldn't find anything specific to discontinuous operation.
Do you have a titel of a paper related to this?
What Driscoll was talking about was self limiting in a
transistor. That is discontinuous operation, although
Driscoll doesn't c
On 11/12/2015 12:04 AM, Hal Murray wrote:
I think it was HP that measured the signal in the Silicon Valley area. NBS
published and distributed the offset.
Does anybody remember that booklet? Did I get the story reasonably accurate?
When I was hired by HP in 1979, my new boss (who was the
On 11/12/2015 1:01 PM, William Schrempp wrote:
has failed. I hear old machinists complaining about new machinists who can't
drill a hole if the drill-press isn't computer-controlled. And in my work,
nurse education, I see students who can't be bothered to learn how to take a
manual blood-press
On 12/9/2015 2:26 AM, Attila Kinali wrote:
Moin,
I just tried to figure out how phase microsteppers are usually build,
but, beside the time-nuts discussion from 10 years ago and US patents
US4358741 and US4417352 my search turned out empty. I am pretty sure
that I used the wrong search terms and
It's been 20 years since I presented that paper in San Francisco
at FCS and I had just about forgotten about it. It is
flattering to realize that people are still reading it now.
It might be useful for the discussion here if I explained why I
wrote the paper. We had recently completed the 5071A
On 12/13/2015 7:15 PM, Tom McDermott wrote:
It brings up a question: Is it possible to estimate the phase noise of that
internal crystal from the ADEV measurements? There are a bunch of
papers that go the other way: from Phase Noise to Adev. Searching
brings up only one paper that goes from
On 1/5/2016 12:07 PM, Bruce Griffiths wrote:
The noise of such Gilbert cell based analog multipliers far exceeds that of the
traditional mixer.
Bruce
Read Gilbert's paper or Gray and Meyers analog IC textbook and
you will see that the whole theory of operation of these
depends on keeping the
On 1/7/2016 4:35 AM, Attila Kinali wrote:
How about using the Gilbert Cell as "digital" mixer,
ie driving the currents hard from one branch to the other
and replacing the current sources by resistors?
How much would that improve the noise? Would it be still much
worse than the diode mixer?
On 1/7/2016 3:11 PM, Bob Camp wrote:
Hi
If your intention is to run a mixer with saturated inputs …. just run
an X-OR gate. It will handle the high level signals much better than
an over-driven analog part.
Bob
If you look at the schematic of an XOR gate IC and compare it
to the schemati
On 1/9/2016 12:44 PM, Attila Kinali wrote:
The purpose of the input circuit is to convert the RF input signal
into a low-jitter square wave that can drive the PIC clock input.
The circuit is closely based on the one published by Wenzel at
http://www.wenzel.com/documents/waveform.html, with modif
mans substitute for the multistage
zero crossing detectors discussed on this forum many
times.
Rick
On 1/10/2016 2:24 AM, Attila Kinali wrote:
Hi Rick,
On Sat, 9 Jan 2016 14:45:43 -0800
"Richard (Rick) Karlquist" wrote:
This circuit is very similar to one that was championed by To
Phase frequency detectors (starting with the legendary MC4044)
being made out of flip flops, had metastability and/or race
conditions. Motorola showed a block diagram made of gates,
as if it were combinatorial logic, but because of the feedback,
it is actually a state machine, as described in the
On 1/14/2016 12:35 PM, Nathan Johnson wrote:
What does the group think of the HP 8660? Just scored a broken one too cheap to
pass up. I know it's not gonna be the last signal generator I buy, but for under
$100 shipped it should be an interesting project.
Nathan KK4REY
When I worked at HP, I
It is interesting that the HP8662A multiplies 10 MHz to 640 MHz,
in steps of 2X. But there is a crystal filter at 80 MHz to
clean up the wideband noise of the 10811. In the 11729, they
filter the 640 MHz from the 8662 with a SAW filter, again to
eliminate multiplied up wideband noise. It's goin
On 1/26/2016 11:52 AM, walter shawlee 2 wrote:
I have been working on a compact portable 10Mhz bench standard
using both an FE FE5680A Rb oscillator and an Oscilloquartz ovenized
It is important for a 10 MHz source to launch a pure sine wave
and also to have an accurate 50 ohm impedance at 10
On 1/22/2016 2:14 PM, Mathew Breton wrote:
I was gifted an HP 5370B with the usual problem: front-end problems, probably
due to overstress. It is currently up and running again with a set of 5345A
series A3/A4 boards as I wasn't able to get a cheap pair of 5088-706x hybrid
ICs.
This sounds lik
Vintage HP equipment often had HP made power transformers,
which ran all the time whether the equipment was on or off.
The core loss while idling could be fairly high. The
core was usually just below saturation, so that if the
power switch was on 100V, it would really get hot.
There was some log
On 2/11/2016 2:56 PM, ws at Yahoo via time-nuts wrote:
Joe
The inner oven voltage needs to be stable! To better than 0.1V.
Unlike the single oven unit, the inner oven on the dual oven unit runs fine
at 15 Volts. It draws a couple hundred ma after warm-up.
It's been a long time, but IIRC, it w
On 2/12/2016 12:14 PM, Joseph Gray wrote:
I sent my HP 3457A in for cal. I should be getting it back next week.
I won't mention where I sent it, but it wasn't Keysight (I don't like
that name). I recently changed the SRAM battery and purposely did not
I left Agilent just before the split, but I
A few clarifications:
Before 1999, HP had a Medical Division that made
equipment you saw in hospitals and a Scientific
Instrument Division that made chemical analysis
equipment used in medical laboratories (and also
other laboratories). IIRC, both began as
acquisitions. The Agilent spin off in
On 2/14/2016 11:20 AM, William H. Fite wrote:
They don't wonder; they know very well. But they're stuck. Consider
oscilloscopes. Why pay for a Keysight or Tectronix or LeCroy or, God
forbid, a Rohde & Schwarz when, for the vast majority of applications, a
Rigol will give you everything you need
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