Egg on Face (was EPE - GPS Frequency Reference Project)
Hi,
There's a subtle difference between 3rd phase detectors in the 74HC4046A
(Philips/NXP, ON, TI) and the 74HC4046 (Fairchild, NS)
The 3rd Phase detector in the 74HC4046A works as the designer intended
in the GPSDO circuit, the 3rd phase detector in the 74HC4046 does not.
The 74HC4046 uses an RS flipflop for the 3rd phase detector and requires
narrow pulses on the R and S inputs.
The 74HC4046A uses extra internal gates to ensure that only narrow
pulses are seen by the RS flipflop in the 3rd phase detector.
Bruce
You are perfectly correct. I hadn't noticed that there was a 74HC4046A
fitted to the board in the article but just a plain 74HC4046 shown in
the parts list. However, it is something to watch out for as this will
be a popular project among those, like myself, who do not need to slice
time quite so finely.
Cheers - Joe G3LLV
The old King Radio (then Bendix-King now part of Honeywell) Silver crown aircraft radios used 4046's in some of the synthesisers. The one in the VHF com had a different King part number to that in the ADF (MF direction finder). While trouble shooting we tried an ADF chip in a VHF (didn't have the VHF part in stock). It sort of worked but was slow to lock-up at the ends of the frequency range. Ordered some of the correct parts, both ADF and VHF. They all had the same manufacturer's part number and date code but different King numbers overstamped. Appaently the selected then at the factory for low noise (ADF) or wide pull-in (VHF).
Robert G8RPI.
--- On Sun, 27/9/09, Joe McElvenney ximac@btinternet.com wrote:
From: Joe McElvenney ximac@btinternet.com
Subject: [time-nuts] Egg on Face (was EPE - GPS Frequency Reference Project)
To: "Time Nuts Digest" time-nuts@febo.com
Date: Sunday, 27 September, 2009, 11:00 AM
Hi,
There's a subtle difference between 3rd phase detectors
in the 74HC4046A
(Philips/NXP, ON, TI) and the 74HC4046 (Fairchild, NS)
The 3rd Phase detector in the 74HC4046A works as the
designer intended
in the GPSDO circuit, the 3rd phase detector in the
74HC4046 does not.
The 74HC4046 uses an RS flipflop for the 3rd phase
detector and requires
narrow pulses on the R and S inputs.
The 74HC4046A uses extra internal gates to ensure that
only narrow
pulses are seen by the RS flipflop in the 3rd phase
detector.
Bruce
You are perfectly correct. I hadn't noticed that there was
a 74HC4046A
fitted to the board in the article but just a plain
74HC4046 shown in
the parts list. However, it is something to watch out for
as this will
be a popular project among those, like myself, who do not
need to slice
time quite so finely.
Cheers - Joe G3LLV
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.
Margina design? ;) Better said, very poor design.
Does not sound very good that same part, same lot code, sometimes work
here but not there, sometimes does not work at all... Extending it a
bit... sometimes will work at a given temperature, sometimes will not at
a given other.
Regards,
Javier
Robert Atkinson escribió:
The old King Radio (then Bendix-King now part of Honeywell) Silver crown aircraft radios used 4046's in some of the synthesisers. The one in the VHF com had a different King part number to that in the ADF (MF direction finder). While trouble shooting we tried an ADF chip in a VHF (didn't have the VHF part in stock). It sort of worked but was slow to lock-up at the ends of the frequency range. Ordered some of the correct parts, both ADF and VHF. They all had the same manufacturer's part number and date code but different King numbers overstamped. Appaently the selected then at the factory for low noise (ADF) or wide pull-in (VHF).
Robert G8RPI.
--- On Sun, 27/9/09, Joe McElvenney ximac@btinternet.com wrote:
From: Joe McElvenney ximac@btinternet.com
Subject: [time-nuts] Egg on Face (was EPE - GPS Frequency Reference Project)
To: "Time Nuts Digest" time-nuts@febo.com
Date: Sunday, 27 September, 2009, 11:00 AM
Hi,
There's a subtle difference between 3rd phase detectors
in the 74HC4046A
(Philips/NXP, ON, TI) and the 74HC4046 (Fairchild, NS)
The 3rd Phase detector in the 74HC4046A works as the
designer intended
in the GPSDO circuit, the 3rd phase detector in the
74HC4046 does not.
The 74HC4046 uses an RS flipflop for the 3rd phase
detector and requires
narrow pulses on the R and S inputs.
The 74HC4046A uses extra internal gates to ensure that
only narrow
pulses are seen by the RS flipflop in the 3rd phase
detector.
Bruce
You are perfectly correct. I hadn't noticed that there was
a 74HC4046A
fitted to the board in the article but just a plain
74HC4046 shown in
the parts list. However, it is something to watch out for
as this will
be a popular project among those, like myself, who do not
need to slice
time quite so finely.
Cheers - Joe G3LLV
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.
--
Javier Herrero EMAIL: jherrero@hvsistemas.com
HV Sistemas S.L. PHONE: +34 949 336 806
Los Charcones, 17A FAX: +34 949 336 792
19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com
On 9/27/09 7:22 AM, "Javier Herrero" jherrero@hvsistemas.es wrote:
Margina design? ;) Better said, very poor design.
Does not sound very good that same part, same lot code, sometimes work
here but not there, sometimes does not work at all... Extending it a
bit... sometimes will work at a given temperature, sometimes will not at
a given other.
Regards,
Javier
Robert Atkinson escribió:
The old King Radio (then Bendix-King now part of Honeywell) Silver crown
aircraft radios used 4046's in some of the synthesisers.
Not always marginal or poor design. Sometimes, you can't get the
performance needed with (any) part that simply meets the datasheet specs, so
hand selection is needed. Picking matched pairs is a time honored method
for instance.. In some cases, the mfr does the picking for you (RF power
transistors). In another case, there's an extremely low noise FET used in
some charge amplifiers that not only has to come from one mfr
(notwithstanding the 2N JEDEC number) but you want to buy a bunch and pick
the quietest one. High value resistors and leakage currents also come to
mind.
Yes, of course, some applications needs the parts that are in the better
side of the distribution curve for a particular parameter and for a
particularly stringent application, as you mention :), but I think that
a 4046 seems a part that should not have to be so critical that even in
the same lot number some work, some don't, and it is hard to believe
that no alternatives existed on that time that could have avoided the
high costly selection process.
Regards,
Javier
Lux, Jim (337C) escribió:
On 9/27/09 7:22 AM, "Javier Herrero" jherrero@hvsistemas.es wrote:
Margina design? ;) Better said, very poor design.
Does not sound very good that same part, same lot code, sometimes work
here but not there, sometimes does not work at all... Extending it a
bit... sometimes will work at a given temperature, sometimes will not at
a given other.
Regards,
Javier
Robert Atkinson escribió:
The old King Radio (then Bendix-King now part of Honeywell) Silver crown
aircraft radios used 4046's in some of the synthesisers.
Not always marginal or poor design. Sometimes, you can't get the
performance needed with (any) part that simply meets the datasheet specs, so
hand selection is needed. Picking matched pairs is a time honored method
for instance.. In some cases, the mfr does the picking for you (RF power
transistors). In another case, there's an extremely low noise FET used in
some charge amplifiers that not only has to come from one mfr
(notwithstanding the 2N JEDEC number) but you want to buy a bunch and pick
the quietest one. High value resistors and leakage currents also come to
mind.
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.
--
Javier Herrero EMAIL: jherrero@hvsistemas.com
HV Sistemas S.L. PHONE: +34 949 336 806
Los Charcones, 17A FAX: +34 949 336 792
19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com
The only portion of the device with possibly significant variability is the
VCO. If the design does not take care of the VCO variability, for the
capture range of the PLL; things may not work.
If the device had a Phase-Frequency detector, instead of a phase detector,
the capture range would not be a problem. Phase detectors are OK, when an
acquisition aid is available or when the PLL closed loop BW is much larger
than the max phase rate a start up.
I am surprised to hear that such kind of sloppy design was allowed to be
released. When I worked at Rockwell-Collins, such thing would have been a
big No-No!
Regards,
Francesco
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On
Behalf Of Javier Herrero
Sent: Sunday, September 27, 2009 9:23 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 4046 variations (was EPE GPS....)
Margina design? ;) Better said, very poor design.
Does not sound very good that same part, same lot code, sometimes work
here but not there, sometimes does not work at all... Extending it a
bit... sometimes will work at a given temperature, sometimes will not at
a given other.
Regards,
Javier
Robert Atkinson escribió:
The old King Radio (then Bendix-King now part of Honeywell) Silver crown
aircraft radios used 4046's in some of the synthesisers. The one in the VHF
com had a different King part number to that in the ADF (MF direction
finder). While trouble shooting we tried an ADF chip in a VHF (didn't have
the VHF part in stock). It sort of worked but was slow to lock-up at the
ends of the frequency range. Ordered some of the correct parts, both ADF and
VHF. They all had the same manufacturer's part number and date code but
different King numbers overstamped. Appaently the selected then at the
factory for low noise (ADF) or wide pull-in (VHF).
Robert G8RPI.
--- On Sun, 27/9/09, Joe McElvenney ximac@btinternet.com wrote:
From: Joe McElvenney ximac@btinternet.com
Subject: [time-nuts] Egg on Face (was EPE - GPS Frequency Reference
Project)
To: "Time Nuts Digest" time-nuts@febo.com
Date: Sunday, 27 September, 2009, 11:00 AM
Hi,
There's a subtle difference between 3rd phase detectors
in the 74HC4046A
(Philips/NXP, ON, TI) and the 74HC4046 (Fairchild, NS)
The 3rd Phase detector in the 74HC4046A works as the
designer intended
in the GPSDO circuit, the 3rd phase detector in the
74HC4046 does not.
The 74HC4046 uses an RS flipflop for the 3rd phase
detector and requires
narrow pulses on the R and S inputs.
The 74HC4046A uses extra internal gates to ensure that
only narrow
pulses are seen by the RS flipflop in the 3rd phase
detector.
Bruce
You are perfectly correct. I hadn't noticed that there was
a 74HC4046A
fitted to the board in the article but just a plain
74HC4046 shown in
the parts list. However, it is something to watch out for
as this will
be a popular project among those, like myself, who do not
need to slice
time quite so finely.
Cheers - Joe G3LLV
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
--
Javier Herrero EMAIL: jherrero@hvsistemas.com
HV Sistemas S.L. PHONE: +34 949 336 806
Los Charcones, 17A FAX: +34 949 336 792
19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com
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On 9/27/09 9:54 AM, "Javier Herrero" jherrero@hvsistemas.es wrote:
Yes, of course, some applications needs the parts that are in the better
side of the distribution curve for a particular parameter and for a
particularly stringent application, as you mention :), but I think that
a 4046 seems a part that should not have to be so critical that even in
the same lot number some work, some don't, and it is hard to believe
that no alternatives existed on that time that could have avoided the
high costly selection process.
Regards,
Javier
Lux, Jim (337C) escribió:
Not always marginal or poor design. Sometimes, you can't get the
performance needed with (any) part that simply meets the datasheet specs, so
hand selection is needed. Picking matched pairs is a time honored method
for instance.. In some cases, the mfr does the picking for you (RF power
transistors). In another case, there's an extremely low noise FET used in
some charge amplifiers that not only has to come from one mfr
(notwithstanding the 2N JEDEC number) but you want to buy a bunch and pick
the quietest one. High value resistors and leakage currents also come to
mind.
That was an aircraft radio, and while I don't know a whole bunch about what
certification requirements they have, but for spaceflight, we often use
older (design-wise) parts which have a "flight heritage", even though the
performance is not what you could get with a more modern part (even if the
new part is available as Class S). (anyone know of a flight qualified opamp
to replace the venerable OP27.. Not that the OP27 isn't good, but a lower
power, lower noise, wider band device is always nice to find)
I could see the radio having been designed years and years ago, when the
4046 was all you could get, and even with the cost of hand selecting, it was
still better than the alternative (dozens of carefully selected crystals and
multideck rotary switches). Move forward 10-15 years, and rather than go
through the considerable effort and cost to "certify" a new design, they
just stick with what they have. Then, move forward another 10 years, and
someone needs that radio repaired (I had an early 70s Piper Cherokee in the
80s with the original radios, and I'll bet the next owner kept them for a
while, too.
Yes, I'm also familiarized with space qualified EEE components, and
lately I hear the word "heritage" more frequently that I would like ;)
The only design I've made for aircraft electronics was for a commercial
aircraft application, and the components selection was a lot less
restringent than for space (I think also that the system for which I
worked was also not classified as very critical), so perhaps the
decision to use a 4046 at its limit was driven by that heritage reasons,
and that really there was not too much better things around :) The
venerable 4046 has been around for quite a long time...
Regards,
Javier
Lux, Jim (337C) escribió:
On 9/27/09 9:54 AM, "Javier Herrero" jherrero@hvsistemas.es wrote:
Yes, of course, some applications needs the parts that are in the better
side of the distribution curve for a particular parameter and for a
particularly stringent application, as you mention :), but I think that
a 4046 seems a part that should not have to be so critical that even in
the same lot number some work, some don't, and it is hard to believe
that no alternatives existed on that time that could have avoided the
high costly selection process.
Regards,
Javier
Lux, Jim (337C) escribió:
Not always marginal or poor design. Sometimes, you can't get the
performance needed with (any) part that simply meets the datasheet specs, so
hand selection is needed. Picking matched pairs is a time honored method
for instance.. In some cases, the mfr does the picking for you (RF power
transistors). In another case, there's an extremely low noise FET used in
some charge amplifiers that not only has to come from one mfr
(notwithstanding the 2N JEDEC number) but you want to buy a bunch and pick
the quietest one. High value resistors and leakage currents also come to
mind.
That was an aircraft radio, and while I don't know a whole bunch about what
certification requirements they have, but for spaceflight, we often use
older (design-wise) parts which have a "flight heritage", even though the
performance is not what you could get with a more modern part (even if the
new part is available as Class S). (anyone know of a flight qualified opamp
to replace the venerable OP27.. Not that the OP27 isn't good, but a lower
power, lower noise, wider band device is always nice to find)
I could see the radio having been designed years and years ago, when the
4046 was all you could get, and even with the cost of hand selecting, it was
still better than the alternative (dozens of carefully selected crystals and
multideck rotary switches). Move forward 10-15 years, and rather than go
through the considerable effort and cost to "certify" a new design, they
just stick with what they have. Then, move forward another 10 years, and
someone needs that radio repaired (I had an early 70s Piper Cherokee in the
80s with the original radios, and I'll bet the next owner kept them for a
while, too.
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.
--
Javier Herrero EMAIL: jherrero@hvsistemas.com
HV Sistemas S.L. PHONE: +34 949 336 806
Los Charcones, 17A FAX: +34 949 336 792
19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com
I've started an interesting discussion! I don't know the details of King's selection process, it may have been that that batch would work in either application. Light aircraft avionics designs can be quite interesting. Older designs (I've not looked at any recent ones) would oftrn use chips that had temperature specifications well below the specification of the unit. The "professional" sets would use the industrial or military spec parts. I've designed aircraft equipment where only I or someone with access to the design analysis whould understand why a particular part was selected. The part might look "wrong" without this information. One case was a 3.15A fuse in series with a 27R resistor at the 28V supply input. The fuse can never blow (no the aircraft didn't have 115V 400Hz supplies).
The reason was a pater exercise to obtain intrinsic safety approval without formal testing. The rules said a specific type of fuse must be used at the input, the minimum rating of that approved type of fuse was 3.15A!
Robert G8RPI.
--- On Sun, 27/9/09, Lux, Jim (337C) james.p.lux@jpl.nasa.gov wrote:
From: Lux, Jim (337C) james.p.lux@jpl.nasa.gov
Subject: Re: [time-nuts] 4046 variations (was EPE GPS....)
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Sunday, 27 September, 2009, 6:32 PM
On 9/27/09 9:54 AM, "Javier Herrero" jherrero@hvsistemas.es
wrote:
Yes, of course, some applications needs the parts that
are in the better
side of the distribution curve for a particular
parameter and for a
particularly stringent application, as you mention :),
but I think that
a 4046 seems a part that should not have to be so
critical that even in
the same lot number some work, some don't, and it is
hard to believe
that no alternatives existed on that time that could
have avoided the
high costly selection process.
Regards,
Javier
Lux, Jim (337C) escribió:
Not always marginal or poor design.
Sometimes, you can't get the
performance needed with (any) part that simply
meets the datasheet specs, so
hand selection is needed. Picking matched
pairs is a time honored method
for instance.. In some cases, the mfr does the
picking for you (RF power
transistors). In another case, there's an
extremely low noise FET used in
some charge amplifiers that not only has to come
from one mfr
(notwithstanding the 2N JEDEC number) but you want
to buy a bunch and pick
the quietest one. High value resistors and
leakage currents also come to
mind.
That was an aircraft radio, and while I don't know a whole
bunch about what
certification requirements they have, but for spaceflight,
we often use
older (design-wise) parts which have a "flight heritage",
even though the
performance is not what you could get with a more modern
part (even if the
new part is available as Class S). (anyone know of a flight
qualified opamp
to replace the venerable OP27.. Not that the OP27 isn't
good, but a lower
power, lower noise, wider band device is always nice to
find)
I could see the radio having been designed years and years
ago, when the
4046 was all you could get, and even with the cost of hand
selecting, it was
still better than the alternative (dozens of carefully
selected crystals and
multideck rotary switches). Move forward 10-15 years,
and rather than go
through the considerable effort and cost to "certify" a new
design, they
just stick with what they have. Then, move forward
another 10 years, and
someone needs that radio repaired (I had an early 70s Piper
Cherokee in the
80s with the original radios, and I'll bet the next owner
kept them for a
while, too.
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.
Javier Herrero wrote:
Yes, I'm also familiarized with space qualified EEE components, and
lately I hear the word "heritage" more frequently that I would like ;)
The only design I've made for aircraft electronics was for a commercial
aircraft application, and the components selection was a lot less
restringent than for space (I think also that the system for which I
worked was also not classified as very critical), so perhaps the
decision to use a 4046 at its limit was driven by that heritage reasons,
and that really there was not too much better things around :) The
venerable 4046 has been around for quite a long time...
Surely would other alternatives to the 4046 be possible even within the
scope of heritage components? DBM and active mixers should be available
and useable. The CCO (it's actually current controlled with a V/I
conversion) could also be replaced. Logical gates can also be used to
replace the phase-detector. Not as handy, but the aspect of the 4046
causing trouble could be circumvented if needed. Another aspect is to
improve its performance by design.
But maybe I misinterprent the heritage aspect her in that it is designs
rather than components that is inherited?
Cheers,
Magnus