[time-nuts] Nice Dual mixer and 2 channel counter for DMTD work

[Ralph Devoe]

Are schematics available?

Ralph
___
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.

[time-nuts] 4046 replacement

[Anton Moehammad via time-nuts]

Hi All, I interested in discussion about 4046, in lars GPSDO he use 4046 as 
phase comparator must I replace this Chip for CD74HCT4046A btw I also have many 
TC5081 I wonder how to test the circuit use this chip if have same problem with 
4046.Thank YouAnton
___
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.

Re: [time-nuts] 4046 replacement

[Steve Wilson]

>On 4/18/2018 4:34 AM, John Miles wrote:

>> Ulrich Rohde's book indicates that this problem was first documented in 1978 
>> in an EDN article by some authors named Egan and Clark.  Newer PFDs 
>> implement the 'antibacklash' logic that Rohde mentions.  If you really must 
>> use a 4046, I'd look for a newer version whose data sheet explicitly 
>> addresses this problem.  Better still, use a newer part.

>The book is incorrect.  A patent issued in 1976 (US4023116A)
>covering the Fairchild 11C44 developed by Eric Breeze predates
>the EDN article by several years.  I still remember the big
>splash the 11C44 made when it was introduced in 1976. The Fairchild
>ECL data book had a famous graph comparing it to the MC4044
>in the dead zone.  In those days, Fairchild and Motorola
>were going head to head.  I worked on a synthesizer in 1975
>that used their brand new at the time 11C90 prescaler.

>You can still get 11C44's of a sort by ordering NTE974's
>that claim to be a replacement.

>Rick N6RK

I filed patent 3,810,234 on Aug 21, 1972. It includes a dual-d pfd with
variable delay in the feedback path to eliminate deadband. The term
deadband is not included in the patent since it did not exist at the time.
The google url is

https://patentimages.storage.googleapis.com/53/fc/f0/26d83e477e999a/US3810234.pdf

The dual-d is items 24 and 26 on page 4. The feedback is item 58, and the
variable delay is item 28 on the same page. It turns out the delay was not
needed in production since there was no deadband when it was shorted out.

I recall finding an article on the dual-d pfd that was earlier than my
patent but I forget where I found it.

Ignore the name Steve Wilson. That is my online name to foil id theft and
malware.

Mike Monett
___
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.

Re: [time-nuts] 4046 replacement

[Richard (Rick) Karlquist]

On 4/18/2018 3:15 PM, Magnus Danielson wrote:


The real benefit of the 4044 and 4046 lies in that they where CMOS
devices and integrated well with other CMOS devices, and could help to


The original MC4044 is TTL, not CMOS.  There is a CMOS "CD4044"
but it is something completely different, not even a phase detector at all.

Rick N6RK
___
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.

Re: [time-nuts] 4046 replacement

[Magnus Danielson]

Hi,

On 04/18/2018 10:57 PM, Charles Steinmetz wrote:
> Rick wrote:
> 
>> The book is incorrect.  A patent issued in 1976 (US4023116A)
>> covering the Fairchild 11C44 developed by Eric Breeze predates
>> the EDN article by several years.  I still remember the big
>> splash the 11C44 made when it was introduced in 1976. The Fairchild
>> ECL data book had a famous graph comparing it to the MC4044
>> in the dead zone.
> 
> The attached graph is the one I remember.  Note that, while the 11C44
> was better than the MC4044, neither one was really very linear near zero
> error.  Good multichip PFD designs of the era outperformed both of them.

Gardner thrown at them and suggested to use a mixer instead, as it has
better performance.

The real benefit of the 4044 and 4046 lies in that they where CMOS
devices and integrated well with other CMOS devices, and could help to
make designs more compact. If fills a purpose, but does not necessarily
give you optimum performance.

BTW, as you add noise to the signal, much of the behavior of the
triangle or sawtooth shape of the phase-detector average out to that of
a sine, which is no better than that of a mixer, but what happen in the
process is that the phase detector gain changed, and thus the loop
parameters. If you use a mixer, the phase detector gain becomes less
dependent on the S/N and thus a more stable system behavior.

Cheers,
Magnus
___
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.

Re: [time-nuts] ADEV slopes and measurement mode

[Magnus Danielson]

Hi Ole Petter,

On 04/16/2018 12:12 PM, Ole Petter Ronningen wrote:
> Hi, All
> 
> This will be a bit long, and I apologize for it. Perhaps someone else also
> struggle with the same.
> 
> One of the properties of the familiar ADEV-plots are the slopes - and how
> the slope identify the dominant noise type for the various portions of the
> plots. My understanding is that the slopes stem from "how the noise behaves
> under averaging" - White FM follows the usual white noise slope of
> 1/sqrt(N), or to put it another way; the standard deviation of a set of
> many averages of length N will fall as sqrt(N) when N increases. If the
> standard deviation of the whole non-averaged list is 1, the standard
> deviation of a set of 100-point averages will be 1/10. Other noise types
> does not follow the same 1/sqrt(N) law, hence will give rise to other
> slopes as the number of points averaged increases as we look further to the
> right of the plot.
> 
> If I have already droppped the ball, I'd appreciate a correction..

Hrhrm!

It's not directly averaging but kind of. Ehm. Let me see how to explain
this...

When you measure frequency, one way or another, two time-stamps is
formed. The distance between those two time-stamps will be the
observation time tau. As you count how many cycles, often called events,
that occurred over that time, you can calculate the frequency as
events/time. This is the basis of all traditional counters, which we
these days call Pi-counters, for reasons I will explain separately.

Now, we could be doing this measurement as N sequential back-to-back
measurements, where the stop event becomes the start event of the next
measurmeent. As we sum these up the phase of the stop and the start of
the next cancels and the full sum will become that of the first
start-event and last stop-event. Regardless how we divide it up or not,
it will end up being the same measurement. The averaging thus kind of
cancels out and interestingly does not do anything.

Now, as we attempt to establish the statistical stability of this value
using the normal standard variance and standard deviation methods, also
known as Root Mean Square (RMS) algorithm, we have a bit of a problem,
because the noises of an oscillator is non-convergent. So, an
alternative method to handle that was presented in the 1966 Feb article
by that David Allan. It still provide variance and deviation measures,
but without being caught by the convergence problems.

The ADEV for a certain observation interval is thus an equivalent to
standard deviation measure, to explain how good stability there is for
the measure at that observation interval, regardless of how we divided
the measurement up to form the frequency estimations, as long as they
form a continuous measurement, thus without dead-time.

The slopes stems from how the 1/f^n power distributions of noises gets
inverse Fourier transformed into time-domain, which is the basis for
David Allans article, he uses that out of the M.J.Lighthill "An
introduction to Fourier analysis and generalised functions" and adapts
to the power distributions noises. Because different 1/f^n noises is
dominant in different parts of the spectrum, their slopes in the time
domain will also show the same dominant features and thus be the limit
of precision in our measurement.

Now, if there happens to be gaps in the data as gathered, the dead-time
would cause a bias in the estimated stability, but that bias can be
predicted and thus compensated for, and was passed to a separate bias
function that was also modeled in the same article. That way, the bias
of the counters they had at the time could be overcome to result in
comparable measures.

The obsticle of the averaging over N samples that prohibited the use of
the normal RMS function could be separated out into another bias
function that also was modeled in the article. This way a 5-point
stability measure and a 3-point stability measure could be compared, by
converting it into the 2-point stability measure. The 2-point variance
later became coined Allan's variance and later Allan variance. That
article forged the ring to control the variances.

I can explain more about how the averaging does not give you more help,
but the bias function is good enough. I've done simulations to prove
this to myself and it is really amazing to see it misbehave as soon as
there is a slope there. Classical statistics is out the window.

> Now onto where I confuse myself (assuming I havent already): measuring
> phase vs measuring frequency, and white FM versus white PM. Specifically,
> using a frequency counter to either measure the frequency directly, or
> setting up a time interval measurement to measure phase.

Actually, you tap the data from your counter in two different ways,
either just to get time-stamps one way or another, or get two
time-stamps that has been post-processed into a frequency estimate.

A good crash-coarse on how frequency counters do their dirty work can be
had by 

Re: [time-nuts] 4046 replacement

[Charles Steinmetz]

Rick wrote:


The book is incorrect.  A patent issued in 1976 (US4023116A)
covering the Fairchild 11C44 developed by Eric Breeze predates
the EDN article by several years.  I still remember the big
splash the 11C44 made when it was introduced in 1976. The Fairchild
ECL data book had a famous graph comparing it to the MC4044
in the dead zone.


The attached graph is the one I remember.  Note that, while the 11C44 
was better than the MC4044, neither one was really very linear near zero 
error.  Good multichip PFD designs of the era outperformed both of them.


Best regards,

Charles


___
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.

Re: [time-nuts] 4046 replacement

[Magnus Danielson]

On 04/18/2018 03:17 PM, Charles Steinmetz wrote:
> donald wrote:
> 
>> HEF4046BCN`s, but have
>> recently read that this CMOS IC has a design flaw. What would be a better
>> chip to retrofit?
> 
> As Bill said, the HCT9046 is the improved version of the 4046.
> 
> The "flaw" in the 4046 is a dead zone around zero error in Phase
> Comparator 2 (the PC one generally uses).

It is very bad indeed. Someone chose to use the 4046 to lock up a 155,52
MHz VCXO to a 8 kHz reference, using a 4046 as a core. The charge-pump
was then "accelerated" with a supposedly better charge-pump with a ton
of passives. Turns out that the dead-band was still there to haunt the
designers. The 155,52 MHz was further multiplied to become the 2,48832
Gb/s clock, and as they measured this they had problems with the
jitter/wander of it, as they measured on a rented instruments. Then they
called me in for it. I looked at it and could quickly conclude that the
problem was the dead-band, so that the VCXO coasted up and down after
the push in either side due to the deadband, creating jitter/wander
breaking the standard limits. I concluded that a more continuous
approach was needed, and then they went back to the S/R FF I had
originally proposed, which they natually had ignored and overengineered
something else, and well, look and behold it locked and was well within
margin.

4046 can be cool and nice little critters, but use them wisely where
they work. I try to steer clear from the charge-pump whenever I can.

>  PC2 in the HCT9046 uses
> charge-pump outputs that are biased to avoid the dead zone.  It also
> uses an internal voltage reference, rather than fraction-of-Vdd, to
> minimize drift.

I was about to recommend having a look at the HCT4046, HCT7046 and
HCT9046 series, if one needs something in that family.

Rather than doing charge-pump, an op-amp setup for a integrator in a
PI-loop and a reasonable continuous waveform comparator of choice do
really well. XOR, S/R FF or mixer. The more I work on PLLs, the simpler
they become and the robuster they seem to become.

Cheers,
Magnus
___
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.

Re: [time-nuts] 4046 replacement

[Tisha Hayes]

I too would recommend the  74HCT9046A instead of the 4046.

The data sheet is here;
https://assets.nexperia.com/documents/data-sheet/74HCT9046A.pdf

*Ms. Tisha Hayes*


On Wed, Apr 18, 2018 at 8:27 AM, Bob kb8tq  wrote:

> Hi
>
> If this is a new build, why use a 4046 in the first place? There are many
> newer parts
> that will do all sorts of things. If this is a repair of something that
> has been running
> for years, is it > 5V supply to the chips? If so, you are pretty much
> stuck with 4000
> series CMOS.
>
> There are no fatal flaws in the 4046, but there are basic design
> limitations. Those
> have been well documented over the years and here on the list. Going to a
> better
> part is the answer for that stuff ( = get away from  any 4046 IC).
>
> Bob
>
> > On Apr 18, 2018, at 4:04 AM, donald collie 
> wrote:
> >
> > I have 4  frequency synthesiser projects, each using HEF4046BCN`s, but
> have
> > recently read that this CMOS IC has a design flaw. What would be a better
> > chip to retrofit? I`m thinking perhaps a HEF74HC4046AN [that`s if it
> > doesn`t have the same bug], or a 74HC7046AN - which is similar. Both
> these
> > chips are more-or-less pin compatable TIA for any
> > advice!.
> ..Don
> >
> >  utm_source=link_campaign=sig-email_content=webmail>
> > Virus-free.
> > www.avg.com
> >  utm_source=link_campaign=sig-email_content=webmail>
> > <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
> > ___
> > 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.
>
> ___
> 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.
>
___
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.

Re: [time-nuts] 4046 replacement

[Richard (Rick) Karlquist]

On 4/18/2018 6:27 AM, Bob kb8tq wrote:

Hi

If this is a new build, why use a 4046 in the first place? There are many newer 
parts
that will do all sorts of things. If this is a repair of something that has 
been running
for years, is it > 5V supply to the chips? If so, you are pretty much stuck 
with 4000
series CMOS.

There are no fatal flaws in the 4046, but there are basic design limitations. 
Those
have been well documented over the years and here on the list. Going to a better
part is the answer for that stuff ( = get away from  any 4046 IC).

Bob



Any 4000 series CMOS, besides being extremely slow (prop
delay measured in MICROseconds), have a totem pole output
that momentarily short circuits the power supply when
switching and generates tremendous EMI.

I once wasted several weeks of time running down a spur
problem that I eventually traced to a 4XXX frequency divider.

Rick N6RK

___
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.

Re: [time-nuts] 4046 replacement

[Richard (Rick) Karlquist]

On 4/18/2018 4:34 AM, John Miles wrote:


Ulrich Rohde's book indicates that this problem was first documented in 1978 in 
an EDN article by some authors named Egan and Clark.  Newer PFDs implement the 
'antibacklash' logic that Rohde mentions.  If you really must use a 4046, I'd 
look for a newer version whose data sheet explicitly addresses this problem.  
Better still, use a newer part.


The book is incorrect.  A patent issued in 1976 (US4023116A)
covering the Fairchild 11C44 developed by Eric Breeze predates
the EDN article by several years.  I still remember the big
splash the 11C44 made when it was introduced in 1976. The Fairchild
ECL data book had a famous graph comparing it to the MC4044
in the dead zone.  In those days, Fairchild and Motorola
were going head to head.  I worked on a synthesizer in 1975
that used their brand new at the time 11C90 prescaler.

You can still get 11C44's of a sort by ordering NTE974's
that claim to be a replacement.

Rick N6RK
___
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.

Re: [time-nuts] 4046 replacement

[Bob kb8tq]

Hi

If this is a new build, why use a 4046 in the first place? There are many newer 
parts
that will do all sorts of things. If this is a repair of something that has 
been running
for years, is it > 5V supply to the chips? If so, you are pretty much stuck 
with 4000
series CMOS.

There are no fatal flaws in the 4046, but there are basic design limitations. 
Those
have been well documented over the years and here on the list. Going to a better
part is the answer for that stuff ( = get away from  any 4046 IC).

Bob

> On Apr 18, 2018, at 4:04 AM, donald collie  wrote:
> 
> I have 4  frequency synthesiser projects, each using HEF4046BCN`s, but have
> recently read that this CMOS IC has a design flaw. What would be a better
> chip to retrofit? I`m thinking perhaps a HEF74HC4046AN [that`s if it
> doesn`t have the same bug], or a 74HC7046AN - which is similar. Both these
> chips are more-or-less pin compatable TIA for any
> advice!...Don
> 
> 
> Virus-free.
> www.avg.com
> 
> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
> ___
> 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.

___
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.

Re: [time-nuts] 4046 replacement

[Charles Steinmetz]

donald wrote:


HEF4046BCN`s, but have
recently read that this CMOS IC has a design flaw. What would be a better
chip to retrofit?


As Bill said, the HCT9046 is the improved version of the 4046.

The "flaw" in the 4046 is a dead zone around zero error in Phase 
Comparator 2 (the PC one generally uses).  PC2 in the HCT9046 uses 
charge-pump outputs that are biased to avoid the dead zone.  It also 
uses an internal voltage reference, rather than fraction-of-Vdd, to 
minimize drift.


Note that the 9046 is HCT only (no HC version), meaning that its input 
transition points are TTL standard (not 1/2 Vdd, like normal CMOS logic 
such as HC).


Also note that the HCT9046 has only two phase comparators (PC1 and PC2), 
and does not have  the 4046's PC3 (this is true also of the various 7046 
chips, although they do not share the dead-zone improvement of the 9046).


Best regards,

Charles


___
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.

Re: [time-nuts] 4046 replacement

[Tim Shoppa]

There is no dead time issue at all with 4046 PLL's using the built-in XOR
(Type I) phase detector.

There can be a dead-time issue with 4046 PLL's using the built-in type II
(flip-flop) edge detector.

The 74HCT9046A uses current sources instead of voltage sources in its type
II (flip-flop) edge detector to avoid dead-time issues with this phase
detector.

The Type I phase detector was most commonly used in most 4046 narrowband
PLL applications.

The Type II was mostly used for the applications where the VCO had to track
over most of an octave or more than an octave. Most of these Type II
applications were relatively insensitive to dead time. (Otherwise the
phase-nuts 40 years ago would've noticed. Yes you can hear phase noise even
if they didn't have a good systematic way to measure it back then.)

If your original 4046 circuit has been working fine for the past 40 years
(the 4046 must be 40+ years old now) I see no reason to rip it out and
replace it with the newer variant. You may have trouble finding
through-hole (non-surface mount) 74HCT9046A's at this date anyway.

Tim N3QE

On Wed, Apr 18, 2018 at 5:40 AM, donald collie 
wrote:

> Thankyou Attila. I remember reading a book on PLL theory, recently,writen
> by a very knowledgable fellow, but I didn`t think to make a copy of his
> critique of the 4046. I recall that the nub of it was that the 4046 isn`t
> suitable for some applications because of a design flaw. Perhaps somebody
> in this group could explain further.
> Thankyou Bill, for the datasheet on the 74HCT9046, and your comments
> Cheers!.
> .Don
> jnr ZL4GX
>
>  utm_source=link_campaign=sig-email_content=webmail>
> Virus-free.
> www.avg.com
>  utm_source=link_campaign=sig-email_content=webmail>
> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>
> On Wed, Apr 18, 2018 at 8:28 PM, wb6bnq  wrote:
>
> > Hi Donald,
> >
> > You could consider the NXP 74HCT9046A as a replacement.  It is an
> improved
> > version of 4046.  However, you do need to study the spec sheet as it is a
> > bit different, but in a good way.
> >
> > I have included an attached PDF of the spec sheet, if it makes through
> the
> > mail list server.
> >
> > BillWB6BNQ
> >
> >
> > donald collie wrote:
> >
> > I have 4  frequency synthesiser projects, each using HEF4046BCN`s, but
> have
> >> recently read that this CMOS IC has a design flaw. What would be a
> better
> >> chip to retrofit? I`m thinking perhaps a HEF74HC4046AN [that`s if it
> >> doesn`t have the same bug], or a 74HC7046AN - which is similar. Both
> these
> >> chips are more-or-less pin compatable TIA for any
> >> advice!.
> >> ..Don
> >>
> >>  >> source=link_campaign=sig-email_content=webmail>
> >> Virus-free.
> >> www.avg.com
> >>  >> source=link_campaign=sig-email_content=webmail>
> >> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
> >> ___
> >> time-nuts mailing list -- time-nuts@febo.com
> >> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> >> ailman/listinfo/time-nuts
> >> and follow the instructions there.
> >>
> >>
> >>
> >
> >
> > ___
> > 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.
> >
> ___
> 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.
>
___
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.

Re: [time-nuts] 4046 replacement

[John Miles]

> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of
> donald collie
> Sent: Wednesday, April 18, 2018 2:40 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] 4046 replacement
> 
> Thankyou Attila. I remember reading a book on PLL theory, recently,writen
> by a very knowledgable fellow, but I didn`t think to make a copy of his
> critique of the 4046. I recall that the nub of it was that the 4046 isn`t
> suitable for some applications because of a design flaw. Perhaps somebody
> in this group could explain further.
> Thankyou Bill, for the datasheet on the 74HCT9046, and your comments
> Cheers!..Don
> jnr ZL4GX

The tristate phase/freq comparator in the original 4046 had a dead-band problem 
that caused its gain to vary widely as it approached its normal operating point 
in a stable loop.  This wasn't so much a 'bug' as it was a consequence of the 
fact that there's effectively no gain when there's no phase error to correct.  

Ulrich Rohde's book indicates that this problem was first documented in 1978 in 
an EDN article by some authors named Egan and Clark.  Newer PFDs implement the 
'antibacklash' logic that Rohde mentions.  If you really must use a 4046, I'd 
look for a newer version whose data sheet explicitly addresses this problem.  
Better still, use a newer part.

Another workaround is to force the PFD to stay out of its dead zone by loading 
the output lightly, e.g. with a 1M resistor.  You can never compensate for this 
effect perfectly, though.  You can probably expect some downsides like worse 
reference suppression.  

-- john, KE5FX
Miles Design LLC

___
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.

Re: [time-nuts] 4046 replacement

[REEVES Paul]

Hi Donald,

I've just had this problem - the 'signal' input (p14) to the phase detectors is 
a 'bodge' linear amplifier built around standard CMOS stages and it doesn’t 
work right. A resistor around a CMOS inverter was a good old recipe to get a 
'linear' amplifier stage but this design appears to have a voltage variable 
resistor of sorts and it gives very strange results. It is fine if used as a 
CMOS level i/p stage but its use as an  ac coupled low level i/p is problematic 
and may need additional loading. Manufacturer's documentation is scarce and I 
have only seen one reference to the internal design of this stage. There's 
quite a bit about it in several places on the net.

Regards,
Paul   Reeves  G8GJA

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of donald collie
Sent: 18 April 2018 10:40
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 4046 replacement

Thankyou Attila. I remember reading a book on PLL theory, recently,writen by a 
very knowledgable fellow, but I didn`t think to make a copy of his critique of 
the 4046. I recall that the nub of it was that the 4046 isn`t suitable for some 
applications because of a design flaw. Perhaps somebody in this group could 
explain further.
Thankyou Bill, for the datasheet on the 74HCT9046, and your comments 
Cheers!..Don
jnr ZL4GX


Virus-free.
www.avg.com

<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

On Wed, Apr 18, 2018 at 8:28 PM, wb6bnq  wrote:

> Hi Donald,
>
> You could consider the NXP 74HCT9046A as a replacement.  It is an 
> improved version of 4046.  However, you do need to study the spec 
> sheet as it is a bit different, but in a good way.
>
> I have included an attached PDF of the spec sheet, if it makes through 
> the mail list server.
>
> BillWB6BNQ
>
>
> donald collie wrote:
>
> I have 4  frequency synthesiser projects, each using HEF4046BCN`s, but 
> have
>> recently read that this CMOS IC has a design flaw. What would be a 
>> better chip to retrofit? I`m thinking perhaps a HEF74HC4046AN [that`s 
>> if it doesn`t have the same bug], or a 74HC7046AN - which is similar. 
>> Both these chips are more-or-less pin compatable TIA for any 
>> advice!.
>> ..Don
>>
>> > source=link_campaign=sig-email_content=webmail>
>> Virus-free.
>> www.avg.com
>> > source=link_campaign=sig-email_content=webmail>
>> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>> ___
>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
>> https://www.febo.com/cgi-bin/m ailman/listinfo/time-nuts and follow 
>> the instructions there.
>>
>>
>>
>
>
> ___
> 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.
>
___
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.

___
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.

Re: [time-nuts] 4046 replacement

[donald collie]

Thankyou Attila. I remember reading a book on PLL theory, recently,writen
by a very knowledgable fellow, but I didn`t think to make a copy of his
critique of the 4046. I recall that the nub of it was that the 4046 isn`t
suitable for some applications because of a design flaw. Perhaps somebody
in this group could explain further.
Thankyou Bill, for the datasheet on the 74HCT9046, and your comments
Cheers!..Don
jnr ZL4GX


Virus-free.
www.avg.com

<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

On Wed, Apr 18, 2018 at 8:28 PM, wb6bnq  wrote:

> Hi Donald,
>
> You could consider the NXP 74HCT9046A as a replacement.  It is an improved
> version of 4046.  However, you do need to study the spec sheet as it is a
> bit different, but in a good way.
>
> I have included an attached PDF of the spec sheet, if it makes through the
> mail list server.
>
> BillWB6BNQ
>
>
> donald collie wrote:
>
> I have 4  frequency synthesiser projects, each using HEF4046BCN`s, but have
>> recently read that this CMOS IC has a design flaw. What would be a better
>> chip to retrofit? I`m thinking perhaps a HEF74HC4046AN [that`s if it
>> doesn`t have the same bug], or a 74HC7046AN - which is similar. Both these
>> chips are more-or-less pin compatable TIA for any
>> advice!.
>> ..Don
>>
>> > source=link_campaign=sig-email_content=webmail>
>> Virus-free.
>> www.avg.com
>> > source=link_campaign=sig-email_content=webmail>
>> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
>> ailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>>
>>
>
>
> ___
> 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.
>
___
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.

Re: [time-nuts] 4046 replacement

[Clint Jay]

Why not try one, the 74HC4046 is pin compatible I think, you may need to
make some changes to use the '7046 version but you can then make a value
judgement if the flaw had in fact mainfested itself as a problem in your
design?

On 18 April 2018 at 09:04, donald collie  wrote:

> I have 4  frequency synthesiser projects, each using HEF4046BCN`s, but have
> recently read that this CMOS IC has a design flaw. What would be a better
> chip to retrofit? I`m thinking perhaps a HEF74HC4046AN [that`s if it
> doesn`t have the same bug], or a 74HC7046AN - which is similar. Both these
> chips are more-or-less pin compatable TIA for any
> advice!.
> ..Don
>
>  utm_source=link_campaign=sig-email_content=webmail>
> Virus-free.
> www.avg.com
>  utm_source=link_campaign=sig-email_content=webmail>
> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
> ___
> 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.
>



-- 
Clint. M0UAW IO83

*No trees were harmed in the sending of this mail. However, a large number
of electrons were greatly inconvenienced.*
___
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.

Re: [time-nuts] 4046 replacement

[Attila Kinali]

On Wed, 18 Apr 2018 20:04:02 +1200
donald collie  wrote:

> I have 4  frequency synthesiser projects, each using HEF4046BCN`s, but have
> recently read that this CMOS IC has a design flaw. What would be a better
> chip to retrofit? I`m thinking perhaps a HEF74HC4046AN [that`s if it
> doesn`t have the same bug], or a 74HC7046AN - which is similar. Both these
> chips are more-or-less pin compatable TIA for any

What design flaw are you talking about?

Attila Kinali

-- 
It is upon moral qualities that a society is ultimately founded. All 
the prosperity and technological sophistication in the world is of no 
use without that foundation.
 -- Miss Matheson, The Diamond Age, Neil Stephenson
___
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.

[time-nuts] 4046 replacement

[donald collie]

I have 4  frequency synthesiser projects, each using HEF4046BCN`s, but have
recently read that this CMOS IC has a design flaw. What would be a better
chip to retrofit? I`m thinking perhaps a HEF74HC4046AN [that`s if it
doesn`t have the same bug], or a 74HC7046AN - which is similar. Both these
chips are more-or-less pin compatable TIA for any
advice!...Don


Virus-free.
www.avg.com

<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
___
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.