On Monday, October 30, 2023 at 2:35:12 AM UTC+11, John Larkin wrote:> On Sun, 29 Oct 2023 08:56:07 -0400, Phil Hobbs <pcdhSpamM...@electrooptical.net> wrote: > >On 2023-10-25 06:39, John Larkin wrote: > >> On Wed, 25 Oct 2023 07:18:58 +0300, Dimiter_Popoff <d...@tgi-sci.com> wrote: > >>> On 10/25/2023 1:51, john larkin wrote: > >>>> On Wed, 25 Oct 2023 01:12:21 +0300, Dimiter_Popoff <d...@tgi-sci.com> wrote: > >>>>> On 10/25/2023 0:34, john larkin wrote:<snip>> >You got a reel of custom ones made--do you know how tight their tempco matching is? > > I've only measured a few but they look pretty good. The uncorrected tempco of the oscillator is something like 150 PPM, and I can livewith 25 or so, so the correction need not be perfect.> > What's scary is that most of the TC is in the PCB dielectric, composition and thickness, and that can vary from board batch to batch.So build it as thick film hybrid on alumina. Some of the Rogers microwave printed circuit substrates are teflon bonded alumina which would be equally good. A lot of the problem with epoxy-bonded glass fibre is that the proportion of epoxy to glass fibre varies as you move from one fibre to the next. -- Bill Sloman, Sydney
Tww
Started by ●October 24, 2023
Reply by ●October 30, 20232023-10-30
Reply by ●October 30, 20232023-10-30
On a sunny day (Sun, 29 Oct 2023 18:01:22 -0700 (PDT)) it happened whit3rd <whit3rd@gmail.com> wrote in <cf0c4a74-0e7d-4dba-86f0-62a6b37e02e2n@googlegroups.com>:>On Saturday, October 28, 2023 at 7:49:49 AM UTC-7, John Larkin wrot= >e: >> On Sat, 28 Oct 2023 04:26:51 GMT, Jan Panteltje <al...@comet.invalid> >> wrote: >> >> >On a sunny day (Fri, 27 Oct 2023 15:53:31 -0700) it happened john larkin= > >> ><j...@650pot.com> wrote in <6qfojihekda4aobmg...@4ax.com>: >> > > >> >>The 4046 has a terrible phase detector. >> > >> >HCT4046 has 3 phase detectors. >> >1 xor gate >> >2 A digital memory network. It consists of four flip–flops and s= >ome gating logic, >> > a three state output and a phase pulse output. >> > This comparator acts only on the positive edges of the input signals an= >d is independent of duty cycle. >> >3 A digital four flip–flops and some gating logic a 3 state outp= >ut and a phase pulse output >> > >> >See dataseet >> > >> >So what's your problem :-) >> > >> >I have used the 4046 for many things, nice chip. > >> OK, my mistake, the 4046 has three terrible phase detectors. And one >> terrible VCO. > >The three-detector wasn't the CD4046, but a later 74HC prefixed unit > >For the purpose of a start-now oscillator, none of the 4046 phase detectors= > matter, >only the 'enable' feature, the pin #5 switch for its current sources. > >Ramping up/down my stepping motors with a 4046 was graceful and easy to acc= >omplish.This is very old, a 4046 used in a data decoder in a 5 1/4 inch floppy drive. It was basically an Intel application note for the 8272 but then I did a new type of phase discriminator with analog switches: Thas thing was so good that even if you slowed down the floppy by pushing on it it would still read the correct data. https://panteltje.nl/panteltje/z80/system14/diagrams/fdc-2.jpg https://panteltje.nl/panteltje/z80/system14/diagrams/fdc-1.jpg
Reply by ●October 30, 20232023-10-30
On 10/29/23 23:37, John Larkin wrote:> On Sun, 29 Oct 2023 22:47:23 +0100, Jeroen Belleman > <jeroen@nospam.please> wrote: > >> On 10/29/23 16:28, John Larkin wrote: >>> On Sun, 29 Oct 2023 05:15:08 GMT, Jan Panteltje <alien@comet.invalid> >>> wrote: >>> >>>> On a sunny day (Sat, 28 Oct 2023 07:49:21 -0700) it happened John Larkin >>>> <jl@997PotHill.com> wrote in <no7qji5c7ak2m46cmmuq7misqaqlrt4nkr@4ax.com>: >>>> >>>>> On Sat, 28 Oct 2023 04:26:51 GMT, Jan Panteltje <alien@comet.invalid> >>>>> wrote: >>>>> >>>>>> On a sunny day (Fri, 27 Oct 2023 15:53:31 -0700) it happened john larkin >>>>>> <jl@650pot.com> wrote in <6qfojihekda4aobmgnq71rbf493sa454q0@4ax.com>: >>>>>> >>>>>>> On Thu, 26 Oct 2023 05:06:21 GMT, Jan Panteltje <alien@comet.invalid> >>>>>>> wrote: >>>>>>> >>>>>>>> On a sunny day (Wed, 25 Oct 2023 20:45:52 -0700) it happened John Larkin >>>>>>>> <jl@997PotHill.com> wrote in <hknjjih3rp87naoq2o2pefergou2deg7i4@4ax.com>: >>>>>>>> >>>>>>>>> The trick in a digital delay generator, or at least ours, is to stop >>>>>>>>> an LC oscillator and start it when we get an external trigger, and >>>>>>>>> then use it as our timebase. But lock it to an crystal oscillator to >>>>>>>>> keep long delays accurate. >>>>>>>>> >>>>>>>>> To do that, I need a pretty stable LC oscillator, hence the tempco >>>>>>>>> tuning. Capex made us a reel of custom N4700 ceramic caps, which can >>>>>>>>> be used to compensate the pretty awful inductor and FR4 tempcos. >>>>>>>>> >>>>>>>>> HP made one delay generator that actually started and stopped a >>>>>>>>> crystal oscillator. It didn't work very well. A quartz crystal is hard >>>>>>>>> to kick start and is even worse to stop; it rings like a bell. >>>>>>>> >>>>>>>> All this makes me think about a 4046 and PLL. >>>>>>> >>>>>>> The 4046 has a terrible phase detector. >>>>>> >>>>>> HCT4046 has 3 phase detectors. >>>>>> 1 xor gate >>>>>> 2 A digital memory network. It consists of four flip–flops and some gating logic, >>>>>> a three state output and a phase pulse output. >>>>>> This comparator acts only on the positive edges of the input signals and is independent of duty cycle. >>>>>> 3 A digital four flip–flops and some gating logic a 3 state output and a phase pulse output >>>>>> >>>>>> See dataseet >>>>>> >>>>>> So what's your problem :-) >>>>>> >>>>>> I have used the 4046 for many things, nice chip. >>>>> >>>>> OK, my mistake, the 4046 has three terrible phase detectors. And one >>>>> terrible VCO. >>>> >>>> Well, opinions are still allowed (I hope see https://arstechnica.com/tech-policy/2023/10/the-uks-problematic-online-safety-act-is-now-law/ ) >>>> But it depends on what you call 'terrible' >>>> I have sued 4046 (going back to the old CMOS since the seventies?) for things like FM audio modulation, demodulation, >>>> data clock recovery, what not. >>> >>> The phase-frequency detector has a nanoseconds-wide deadband. That >>> makes for lots of time error and jitter. >>> >>> The XOR detector is just a slow, sloppy XOR gate. >>> >>>> >>>> So do I understand it right if you wanted to sync an LC oscillator with an external pulse, have it restart (so phase shifted) in an instant? >>> >>> My 50 MHz LC oscillator is the coarse count for a triggred delay >>> generator, like this one: >>> >>> http://www.highlandtechnology.com/DSS/P500DS.shtml >>> >>> (We're designing a small embedded version now.) >>> >>> The oscillator is quiescently quenched and kicked off when we get an >>> extrnal trigger. Then it counts off time in 20 ns ticks. That's OK for >>> a microsecond or so, but isn't accurate much longer. So the trick is >>> to phase-lock it to a good XO but preserve its realtionship to the >>> trigger, namely preserve its random phase relationship to the XO. >>> [...] >> >> How do you do that? >> >> Jeroen Belleman > > Digitize the LC oscillator waveform with an ADC that's clocked by the > crystal, and do FPGA math on that to tune a varicap to lock in the > phase relationship. > > The LC is drifting after trigger, so it's prudent to start locking in > under a microsecond. >OK, though I won't pretend I understand how you get to picosecond resolution from that.> Older designs, like the HP 5359A Time Synthesizer and such, didn't > have the advantages that we have now, cheap video ADCs and FPGAs and > phemts and such. But their old manuals are worth studying. > > SRS used to have schematics in their manuals, so I studied them too.Our ancestors sometimes did amazing things, considering the means they had... Jeroen Belleman
Reply by ●October 30, 20232023-10-30
On 10/29/23 23:37, John Larkin wrote:> On Sun, 29 Oct 2023 22:47:23 +0100, Jeroen Belleman > <jeroen@nospam.please> wrote: > >> On 10/29/23 16:28, John Larkin wrote: >>> On Sun, 29 Oct 2023 05:15:08 GMT, Jan Panteltje <alien@comet.invalid> >>> wrote: >>> >>>> On a sunny day (Sat, 28 Oct 2023 07:49:21 -0700) it happened John Larkin >>>> <jl@997PotHill.com> wrote in <no7qji5c7ak2m46cmmuq7misqaqlrt4nkr@4ax.com>: >>>> >>>>> On Sat, 28 Oct 2023 04:26:51 GMT, Jan Panteltje <alien@comet.invalid> >>>>> wrote: >>>>> >>>>>> On a sunny day (Fri, 27 Oct 2023 15:53:31 -0700) it happened john larkin >>>>>> <jl@650pot.com> wrote in <6qfojihekda4aobmgnq71rbf493sa454q0@4ax.com>: >>>>>> >>>>>>> On Thu, 26 Oct 2023 05:06:21 GMT, Jan Panteltje <alien@comet.invalid> >>>>>>> wrote: >>>>>>> >>>>>>>> On a sunny day (Wed, 25 Oct 2023 20:45:52 -0700) it happened John Larkin >>>>>>>> <jl@997PotHill.com> wrote in <hknjjih3rp87naoq2o2pefergou2deg7i4@4ax.com>: >>>>>>>> >>>>>>>>> The trick in a digital delay generator, or at least ours, is to stop >>>>>>>>> an LC oscillator and start it when we get an external trigger, and >>>>>>>>> then use it as our timebase. But lock it to an crystal oscillator to >>>>>>>>> keep long delays accurate. >>>>>>>>> >>>>>>>>> To do that, I need a pretty stable LC oscillator, hence the tempco >>>>>>>>> tuning. Capex made us a reel of custom N4700 ceramic caps, which can >>>>>>>>> be used to compensate the pretty awful inductor and FR4 tempcos. >>>>>>>>> >>>>>>>>> HP made one delay generator that actually started and stopped a >>>>>>>>> crystal oscillator. It didn't work very well. A quartz crystal is hard >>>>>>>>> to kick start and is even worse to stop; it rings like a bell. >>>>>>>> >>>>>>>> All this makes me think about a 4046 and PLL. >>>>>>> >>>>>>> The 4046 has a terrible phase detector. >>>>>> >>>>>> HCT4046 has 3 phase detectors. >>>>>> 1 xor gate >>>>>> 2 A digital memory network. It consists of four flip–flops and some gating logic, >>>>>> a three state output and a phase pulse output. >>>>>> This comparator acts only on the positive edges of the input signals and is independent of duty cycle. >>>>>> 3 A digital four flip–flops and some gating logic a 3 state output and a phase pulse output >>>>>> >>>>>> See dataseet >>>>>> >>>>>> So what's your problem :-) >>>>>> >>>>>> I have used the 4046 for many things, nice chip. >>>>> >>>>> OK, my mistake, the 4046 has three terrible phase detectors. And one >>>>> terrible VCO. >>>> >>>> Well, opinions are still allowed (I hope see https://arstechnica.com/tech-policy/2023/10/the-uks-problematic-online-safety-act-is-now-law/ ) >>>> But it depends on what you call 'terrible' >>>> I have sued 4046 (going back to the old CMOS since the seventies?) for things like FM audio modulation, demodulation, >>>> data clock recovery, what not. >>> >>> The phase-frequency detector has a nanoseconds-wide deadband. That >>> makes for lots of time error and jitter. >>> >>> The XOR detector is just a slow, sloppy XOR gate. >>> >>>> >>>> So do I understand it right if you wanted to sync an LC oscillator with an external pulse, have it restart (so phase shifted) in an instant? >>> >>> My 50 MHz LC oscillator is the coarse count for a triggred delay >>> generator, like this one: >>> >>> http://www.highlandtechnology.com/DSS/P500DS.shtml >>> >>> (We're designing a small embedded version now.) >>> >>> The oscillator is quiescently quenched and kicked off when we get an >>> extrnal trigger. Then it counts off time in 20 ns ticks. That's OK for >>> a microsecond or so, but isn't accurate much longer. So the trick is >>> to phase-lock it to a good XO but preserve its realtionship to the >>> trigger, namely preserve its random phase relationship to the XO. >>> [...] >> >> How do you do that? >> >> Jeroen Belleman > > Digitize the LC oscillator waveform with an ADC that's clocked by the > crystal, and do FPGA math on that to tune a varicap to lock in the > phase relationship. > > The LC is drifting after trigger, so it's prudent to start locking in > under a microsecond. >OK, though I won't pretend I understand how you get to picosecond resolution from that.> Older designs, like the HP 5359A Time Synthesizer and such, didn't > have the advantages that we have now, cheap video ADCs and FPGAs and > phemts and such. But their old manuals are worth studying. > > SRS used to have schematics in their manuals, so I studied them too.Our ancestors sometimes did amazing things, considering the means they had... Jeroen Belleman
Reply by ●October 30, 20232023-10-30
On Mon, 30 Oct 2023 09:44:43 +0100, Jeroen Belleman <jeroen@nospam.please> wrote:>On 10/29/23 23:37, John Larkin wrote: >> On Sun, 29 Oct 2023 22:47:23 +0100, Jeroen Belleman >> <jeroen@nospam.please> wrote: >> >>> On 10/29/23 16:28, John Larkin wrote: >>>> On Sun, 29 Oct 2023 05:15:08 GMT, Jan Panteltje <alien@comet.invalid> >>>> wrote: >>>> >>>>> On a sunny day (Sat, 28 Oct 2023 07:49:21 -0700) it happened John Larkin >>>>> <jl@997PotHill.com> wrote in <no7qji5c7ak2m46cmmuq7misqaqlrt4nkr@4ax.com>: >>>>> >>>>>> On Sat, 28 Oct 2023 04:26:51 GMT, Jan Panteltje <alien@comet.invalid> >>>>>> wrote: >>>>>> >>>>>>> On a sunny day (Fri, 27 Oct 2023 15:53:31 -0700) it happened john larkin >>>>>>> <jl@650pot.com> wrote in <6qfojihekda4aobmgnq71rbf493sa454q0@4ax.com>: >>>>>>> >>>>>>>> On Thu, 26 Oct 2023 05:06:21 GMT, Jan Panteltje <alien@comet.invalid> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> On a sunny day (Wed, 25 Oct 2023 20:45:52 -0700) it happened John Larkin >>>>>>>>> <jl@997PotHill.com> wrote in <hknjjih3rp87naoq2o2pefergou2deg7i4@4ax.com>: >>>>>>>>> >>>>>>>>>> The trick in a digital delay generator, or at least ours, is to stop >>>>>>>>>> an LC oscillator and start it when we get an external trigger, and >>>>>>>>>> then use it as our timebase. But lock it to an crystal oscillator to >>>>>>>>>> keep long delays accurate. >>>>>>>>>> >>>>>>>>>> To do that, I need a pretty stable LC oscillator, hence the tempco >>>>>>>>>> tuning. Capex made us a reel of custom N4700 ceramic caps, which can >>>>>>>>>> be used to compensate the pretty awful inductor and FR4 tempcos. >>>>>>>>>> >>>>>>>>>> HP made one delay generator that actually started and stopped a >>>>>>>>>> crystal oscillator. It didn't work very well. A quartz crystal is hard >>>>>>>>>> to kick start and is even worse to stop; it rings like a bell. >>>>>>>>> >>>>>>>>> All this makes me think about a 4046 and PLL. >>>>>>>> >>>>>>>> The 4046 has a terrible phase detector. >>>>>>> >>>>>>> HCT4046 has 3 phase detectors. >>>>>>> 1 xor gate >>>>>>> 2 A digital memory network. It consists of four flip–flops and some gating logic, >>>>>>> a three state output and a phase pulse output. >>>>>>> This comparator acts only on the positive edges of the input signals and is independent of duty cycle. >>>>>>> 3 A digital four flip–flops and some gating logic a 3 state output and a phase pulse output >>>>>>> >>>>>>> See dataseet >>>>>>> >>>>>>> So what's your problem :-) >>>>>>> >>>>>>> I have used the 4046 for many things, nice chip. >>>>>> >>>>>> OK, my mistake, the 4046 has three terrible phase detectors. And one >>>>>> terrible VCO. >>>>> >>>>> Well, opinions are still allowed (I hope see https://arstechnica.com/tech-policy/2023/10/the-uks-problematic-online-safety-act-is-now-law/ ) >>>>> But it depends on what you call 'terrible' >>>>> I have sued 4046 (going back to the old CMOS since the seventies?) for things like FM audio modulation, demodulation, >>>>> data clock recovery, what not. >>>> >>>> The phase-frequency detector has a nanoseconds-wide deadband. That >>>> makes for lots of time error and jitter. >>>> >>>> The XOR detector is just a slow, sloppy XOR gate. >>>> >>>>> >>>>> So do I understand it right if you wanted to sync an LC oscillator with an external pulse, have it restart (so phase shifted) in an instant? >>>> >>>> My 50 MHz LC oscillator is the coarse count for a triggred delay >>>> generator, like this one: >>>> >>>> http://www.highlandtechnology.com/DSS/P500DS.shtml >>>> >>>> (We're designing a small embedded version now.) >>>> >>>> The oscillator is quiescently quenched and kicked off when we get an >>>> extrnal trigger. Then it counts off time in 20 ns ticks. That's OK for >>>> a microsecond or so, but isn't accurate much longer. So the trick is >>>> to phase-lock it to a good XO but preserve its realtionship to the >>>> trigger, namely preserve its random phase relationship to the XO. >>>> [...] >>> >>> How do you do that? >>> >>> Jeroen Belleman >> >> Digitize the LC oscillator waveform with an ADC that's clocked by the >> crystal, and do FPGA math on that to tune a varicap to lock in the >> phase relationship. >> >> The LC is drifting after trigger, so it's prudent to start locking in >> under a microsecond. >> > >OK, though I won't pretend I understand how you get to picosecond >resolution from that. > >> Older designs, like the HP 5359A Time Synthesizer and such, didn't >> have the advantages that we have now, cheap video ADCs and FPGAs and >> phemts and such. But their old manuals are worth studying. >> >> SRS used to have schematics in their manuals, so I studied them too. > >Our ancestors sometimes did amazing things, considering the means they >had... > >Jeroen BellemanThe HP5370 time-interval counter had/has 20 ps picosecond resolution and about a 30 ps RMS noise floor. The new Keysight equivalent is, as I recall, about twice as good on jitter. After 40 years! The 5370 is astounding. It does amazing measurements with an MC6800 CPU, less compute power than a toaster has nowadays. The user interface is wonderful too. The Keysight 53200 will not display an N-sample running jitter measurement! The 5370 did that.
Reply by ●October 30, 20232023-10-30
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>>> I highly recommend a good set of curved jaw tweezers, with a tiny >>> binder clip on the hinge end.�� That lets you micro-adjust the tension >>> by sliding the clip, so that they open when you squeeze them edgeways, >>> and close very gently when you release. >> >> This sounds interesting, would you please post a photo? >> I manage with my normal tweezers, two of those I have are good enough >> to get me through placing placing a lot of 0402-s, not too hard >> especially if the paste has not begun to dry so they stick. But >> yours might be helpful on less standard operations... >> >> > > Something like these: > > <https://www.amazon.com/Officemate-Micro-Binder-Clips-31030/dp/B003U4U3YQ > >. > > You take off the silver handles and just use the black spring part. > That and a little jar of acetone for cleaning flux off the tweezers > makes an excellent combination that reduces the tiddly-wink problem by a > lot. > > Cheers > > Phil HobbsTweezers can still lose the parts, and may have some difficulty removing parts from the tape. The binder clips require two hands, and fumbling around trying to get the part aligned with the mounting point may case it to pop out of the tweezers and get lost. What is needed is a method that firmly fixes the component while it is being transported from the tape to the pcb, provides easy 360 degree rotation of the part for alignment, and only requires one hand for operation. A simple vacuum system seems to be ideal. Here is probably the simplest: DIY Vacuum Pen https://www.youtube.com/watch?v=sYZ2oqnYb3s Many other approaches are possible. Here are a few: Electric Vacuum Pen From Aquarium Air Pump. : 43 Steps (with Pictures) - Instructables https://www.instructables.com/Electric-Vacuum-Pen-From-Aquarium-Air-Pump/ SHANNA Vacuum Suction Pen IC SMD SMT BGA Chip Pick Up Tool Pump Vacuum Pick-Up Tool Suction Pen 110V 12000pa - Walmart.com https://www.walmart.com/ip/SHANNA-Vacuum-Suction-Pen-IC-SMD-SMT-BGA-Chip- Pick-Up-Tool-Pump-Vacuum-Pick-Up-Tool-Suction-Pen-110V-12000pa/205278108 EasyPick - Vacuum Suction Pen - Vassal Ventures https://www.youtube.com/shorts/B04_6YPQWKs Pick-It-Up Vacuum Tool https://www.youtube.com/watch?v=_K0G8COZrSE DIY Vacuum Pick -N- Place Tool - Build Tips & Demo https://www.youtube.com/watch?v=0YG8ipZlM_E SDG #057 Make a Manual Pick and Place Tool for SMD Assembly and Rework https://www.youtube.com/watch?v=9G510G2gmdo Cheap DIY Manual Pick and Place Vacuum Tweezers for Small SMT Parts or Jewellery https://www.youtube.com/watch?v=BrVah3kQTH4 How to make a electric vacuum pump for $10 https://www.youtube.com/watch?v=oGb-UwAXicI Low-Cost Vacuum Pick-Up Tool for Surface-Mount PCB Assembly https://www.youtube.com/watch?v=Oq-NuH2dwlI DIY Manual SMD Vacuum Pick And Place Tool https://www.youtube.com/watch?v=qJWUUK1s_G0 How to Make a Low Cost Vacuum Pickup Tool for SMT Pick and Place https://www.youtube.com/watch?v=wcxNrJXnznc -- MRM
Reply by ●October 30, 20232023-10-30
On 2023-10-30 20:19, Mike Monett VE3BTI wrote:> Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: > >>>> I highly recommend a good set of curved jaw tweezers, with a tiny >>>> binder clip on the hinge end.¶ÿ That lets you micro-adjust the tension >>>> by sliding the clip, so that they open when you squeeze them edgeways, >>>> and close very gently when you release. >>> >>> This sounds interesting, would you please post a photo? >>> I manage with my normal tweezers, two of those I have are good enough >>> to get me through placing placing a lot of 0402-s, not too hard >>> especially if the paste has not begun to dry so they stick. But >>> yours might be helpful on less standard operations... >>> >>> >> >> Something like these: >> >> <https://www.amazon.com/Officemate-Micro-Binder-Clips-31030/dp/B003U4U3YQ >>> . >> >> You take off the silver handles and just use the black spring part. >> That and a little jar of acetone for cleaning flux off the tweezers >> makes an excellent combination that reduces the tiddly-wink problem by a >> lot. >> >> Cheers >> >> Phil Hobbs > > Tweezers can still lose the parts, and may have some difficulty removing > parts from the tape. The binder clips require two hands, and fumbling > around trying to get the part aligned with the mounting point may case it > to pop out of the tweezers and get lost. > > What is needed is a method that firmly fixes the component while it is > being transported from the tape to the pcb, provides easy 360 degree > rotation of the part for alignment, and only requires one hand for > operation. > > A simple vacuum system seems to be ideal. Here is probably the simplest: > > DIY Vacuum Pen > https://www.youtube.com/watch?v=sYZ2oqnYb3s<snip> I cordially dislike vacuum pens, though I know some folks like them a lot. I have one, but rarely use it. You have to change tips to go from doing chips to doing small parts, or else your 0402s get sucked right up the hose. A pain. Dumping a couple of parts out of a tape is pretty simple--the issue is holding them in the right position and orientation long enough to get at least one lead soldered down. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●October 30, 20232023-10-30
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:> I cordially dislike vacuum pens, though I know some folks like them a > lot. I have one, but rarely use it. You have to change tips to go > from doing chips to doing small parts, or else your 0402s get sucked > right up the hose. A pain. > > Dumping a couple of parts out of a tape is pretty simple--the issue is > holding them in the right position and orientation long enough to get at > least one lead soldered down. > > Cheers > > Phil HobbsHow do you handle ic's such as tssop, soic, tsop, etc. With tweezers, there is a risk of mangling the leads. The vacuum approach does not touch the leads. -- MRM
Reply by ●October 30, 20232023-10-30
On 2023-10-30 21:31, Mike Monett VE3BTI wrote:> Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> I cordially dislike vacuum pens, though I know some folks like them a >> lot. I have one, but rarely use it. You have to change tips to go >> from doing chips to doing small parts, or else your 0402s get sucked >> right up the hose. A pain. >> >> Dumping a couple of parts out of a tape is pretty simple--the issue is >> holding them in the right position and orientation long enough to get at >> least one lead soldered down.> > How do you handle ic's such as tssop, soic, tsop, etc. With tweezers, there > is a risk of mangling the leads. The vacuum approach does not touch the > leads.Never recall having a problem with that. I normally hold them by the ends, where there aren't any leads. Of course those parts are big enough that you can just place them with the tweezers and then press them down on the board (usually with the closed jaws) while soldering. I still lose parts, of course, but not nearly as many as I used to. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●October 31, 20232023-10-31
On a sunny day (Mon, 30 Oct 2023 20:28:00 -0400) it happened Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote in <977eb687-c15b-9877-17e3-4abe209283ec@electrooptical.net>:>On 2023-10-30 20:19, Mike Monett VE3BTI wrote: >> Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: >> >>>>> I highly recommend a good set of curved jaw tweezers, with a tiny >>>>> binder clip on the hinge end.¶ÿ That lets you micro-adjust the tension >>>>> by sliding the clip, so that they open when you squeeze them edgeways, >>>>> and close very gently when you release. >>>> >>>> This sounds interesting, would you please post a photo? >>>> I manage with my normal tweezers, two of those I have are good enough >>>> to get me through placing placing a lot of 0402-s, not too hard >>>> especially if the paste has not begun to dry so they stick. But >>>> yours might be helpful on less standard operations... >>>> >>>> >>> >>> Something like these: >>> >>> <https://www.amazon.com/Officemate-Micro-Binder-Clips-31030/dp/B003U4U3YQ >>>> . >>> >>> You take off the silver handles and just use the black spring part. >>> That and a little jar of acetone for cleaning flux off the tweezers >>> makes an excellent combination that reduces the tiddly-wink problem by a >>> lot. >>> >>> Cheers >>> >>> Phil Hobbs >> >> Tweezers can still lose the parts, and may have some difficulty removing >> parts from the tape. The binder clips require two hands, and fumbling >> around trying to get the part aligned with the mounting point may case it >> to pop out of the tweezers and get lost. >> >> What is needed is a method that firmly fixes the component while it is >> being transported from the tape to the pcb, provides easy 360 degree >> rotation of the part for alignment, and only requires one hand for >> operation. >> >> A simple vacuum system seems to be ideal. Here is probably the simplest: >> >> DIY Vacuum Pen >> https://www.youtube.com/watch?v=sYZ2oqnYb3s ><snip> > >I cordially dislike vacuum pens, though I know some folks like them a >lot. I have one, but rarely use it. You have to change tips to go >from doing chips to doing small parts, or else your 0402s get sucked >right up the hose. A pain. > >Dumping a couple of parts out of a tape is pretty simple--the issue is >holding them in the right position and orientation long enough to get at >least one lead soldered down.I just use tweezers, and a magnifying glass (third hand thing). Was just doing all that the last few days, building my gas sensor in a small housing, making a PCB with SMDs, Needs a bit steady hand, no problems, 4 more wires to go and it should work,
