Re: [time-nuts] 4046 variations (was EPE GPS....)
Gentlemen, in http://www.elektronik-kompendium.de/public/schaerer/pll4046.htm which unfortunately is available in German language only (the illustrations however speak for themselves!) the author makes an in depth analysis of the self biasing amplifier circuitry of the 4046's input pin 14 and explains the dos onts donts with this input. Apart from differences of the vco range due to different cmos technologies most of the chip to chip differences seem to have it's origin in this region. Best regards Ulrich Bangert P.S. I don't have all the things I would wish I had, lacking alot of analog databooks. Are you looking for something special? I have a number of old data books that I did not use for at least 15 years, actually they are much older. -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Magnus Danielson Gesendet: Montag, 28. September 2009 00:38 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] 4046 variations (was EPE GPS) Jim, Lux, Jim (337C) wrote: Design AND component... Easy to claim heritage if all you do is change a resistor or a capacitor. Tougher to claim if you change the active components, particularly if it's functionally different (e.g. Substituting a 2n3904 for a 2n isn't a huge deal.. Changing a NPN to a PNP and reversing bias, or using FETs instead of bipolars.. That would be a big deal) Keeping those 30 year old databooks is important.. (as we tell the folks who say: why do you need all that shelf space.. Surely those datasheets are available on line).. 1980s design, modified in 1990s, using parts first available in 1970s, launched in 2000s, gets to Saturn in 2010s, has inflight anomaly.. Oddly, the 4000 series CMOS are still heavily used. Back in the 70s and 80s, I hated those parts because they were ESD sensitive (compared to straight or LS ttl), but by today's standards, they're rock solid, have huge junctions, work at any supply voltage. I have been a fan of keeping old databooks. Keeps collecting them. For instance, in practice my most used databook is the RCA CMOS databook from 1982. Contains some very useful insights into the 4046 design which the online datasheet does not reveal. I don't have all the things I would wish I had, lacking alot of analog databooks. 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. ___ 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 variations (was EPE GPS....)
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 xi...@btinternet.com wrote: From: Joe McElvenney xi...@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.
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 xi...@btinternet.com wrote: From: Joe McElvenney xi...@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 HerreroEMAIL: jherr...@hvsistemas.com HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17AFAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ 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 variations (was EPE GPS....)
On 9/27/09 7:22 AM, Javier Herrero jherr...@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.
Re: [time-nuts] 4046 variations (was EPE GPS....)
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 jherr...@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 HerreroEMAIL: jherr...@hvsistemas.com HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17AFAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ 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 variations (was EPE GPS....)
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-boun...@febo.com [mailto:time-nuts-boun...@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 xi...@btinternet.com wrote: From: Joe McElvenney xi...@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 HerreroEMAIL: jherr...@hvsistemas.com HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17AFAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ 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. E-mail message checked by Spyware Doctor (6.1.0.447) Database version: 6.13350 http://www.pctools.com/en/spyware-doctor-antivirus/ E-mail message checked by Spyware Doctor (6.1.0.447) Database version: 6.13350 http://www.pctools.com/en/spyware-doctor-antivirus/ ___ 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 variations (was EPE GPS....)
On 9/27/09 9:54 AM, Javier Herrero jherr...@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.
Re: [time-nuts] 4046 variations (was EPE GPS....)
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 jherr...@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 HerreroEMAIL: jherr...@hvsistemas.com HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17AFAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ 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 variations (was EPE GPS....)
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@jpl.nasa.gov wrote: From: Lux, Jim (337C) james.p@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 jherr...@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. ___ 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 variations (was EPE GPS....)
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 ___ 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 variations (was EPE GPS....)
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! I've been down a similar road. We designed a low power radio remote control to run some Coal Mining equipment. The regulatory bureaucrats in the UK Coal Mining industry for intrinsic safety told us we *had* to use a particular power diode, don't recall the number any more, or they would not approve our product. That diode leaked more current that our product took while transmitting! If we wanted to use any modern diode, they would let us do that if we paid them nearly a hundred grand to get it tested and approved, and listed by them as an approved component. So we used their diode and put up with the constant complaints about short battery life. :-( -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ 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 variations (was EPE GPS....)
On 9/27/09 1:54 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: 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? Design AND component... Easy to claim heritage if all you do is change a resistor or a capacitor. Tougher to claim if you change the active components, particularly if it's functionally different (e.g. Substituting a 2n3904 for a 2n isn't a huge deal.. Changing a NPN to a PNP and reversing bias, or using FETs instead of bipolars.. That would be a big deal) Keeping those 30 year old databooks is important.. (as we tell the folks who say: why do you need all that shelf space.. Surely those datasheets are available on line).. 1980s design, modified in 1990s, using parts first available in 1970s, launched in 2000s, gets to Saturn in 2010s, has inflight anomaly.. Oddly, the 4000 series CMOS are still heavily used. Back in the 70s and 80s, I hated those parts because they were ESD sensitive (compared to straight or LS ttl), but by today's standards, they're rock solid, have huge junctions, work at any supply voltage. Jim ___ 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 variations (was EPE GPS....)
Jim, Lux, Jim (337C) wrote: Design AND component... Easy to claim heritage if all you do is change a resistor or a capacitor. Tougher to claim if you change the active components, particularly if it's functionally different (e.g. Substituting a 2n3904 for a 2n isn't a huge deal.. Changing a NPN to a PNP and reversing bias, or using FETs instead of bipolars.. That would be a big deal) Keeping those 30 year old databooks is important.. (as we tell the folks who say: why do you need all that shelf space.. Surely those datasheets are available on line).. 1980s design, modified in 1990s, using parts first available in 1970s, launched in 2000s, gets to Saturn in 2010s, has inflight anomaly.. Oddly, the 4000 series CMOS are still heavily used. Back in the 70s and 80s, I hated those parts because they were ESD sensitive (compared to straight or LS ttl), but by today's standards, they're rock solid, have huge junctions, work at any supply voltage. I have been a fan of keeping old databooks. Keeps collecting them. For instance, in practice my most used databook is the RCA CMOS databook from 1982. Contains some very useful insights into the 4046 design which the online datasheet does not reveal. I don't have all the things I would wish I had, lacking alot of analog databooks. 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.
