I don't know if this helps, but look at the simulation below. This assumes a dielectric constant of 2 for the BNC Tee and a distance of 46mm between the probes. The simulation is a harmonic balance simulation at 500MHz. You can see there is about a 2.9dB difference in voltage between the two nodes TP1 and TP2 at 500MHz. The HB simulation assumes steady state has been reached. It's entirely up to you if you want to declare this difference as 'negligible'. However, I urge you to study it closely. The 10073C has a lower impedance at 500MHz yet it has the higher voltage compared to the higher impedance Zo probe. This happens at equilibrium (steady state) after lots of reflections back and forth. Most people would expect the voltage to be higher at the Zo probe TP2 but it isn't. You have to analyse how the system achieves steady state in order to understand that there will a 2-3dB difference between TP1 and TP2 at 500MHz. 
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Re: HP8568B battery replacement
My had both, but I concluded that the big one (HP-67 style) was not used, so I changed only that on board and it works.
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JMR said:
"If the 3.5GHz 'known good probe' probe is a passive Zo probe, it might look like 500R in parallel with 1pF up at UHF. By contrast, a 10073C will typically look like about 60R in parallel with about 7pF across 400MHz to 500MHz. Quite a difference.
This is going to upset the balance of Robert's BNC Tee based system. There's no way it will have any integrity up at 500MHz if I assume the distance between the probes is going to be about 45mm. This allows for the length of the Tee piece and some additional length for each BNC probe adaptor. This is a significant length at 500MHz. It should be obvious that the voltages arriving at the inputs of the two probes won't be the same at 500MHz, it isn't a valid test method for this reason."
Firstly the measurement is only up to 350MHz but even if we are talking 500MHz the wavelength is 600mm If the T is? 50mm across the differnce between the two loads is 25mm (probably less) so only 15 degrees phase difference.? Noting that we are trying to determine a 3dB bandwidth in a non-phase sensitive level measurement I would consider that the error is insignificant.
?
?
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Re: HP8568B battery replacement
I'm not absolutely sure of the details, but as I recall, the 8568A (and 8566A) to "B" conversions changed it from an off-board 3-cell NiCd HP35 calculator-style pack, to a single 3V Li-ion cell soldered right on the (new design) processor board. Some of the info may be missing because of all the big changes involved. There were total swap-outs of the brain system, plus a field-installed A-B upgrade offered around the same time.
If you have a "B" of whichever, you should find the backup Li cell on the uP board, in the right-rear board cage compartment of the RF section, viewed from the top, as I recall. Or was it the bottom? The structure is such that the 8566 RF unit is accessed upside down, and I don't recall if the 8568 is the same. I know for sure that whatever the arrangement, the uP board is right next to the GPIB board, so just find that from the outside. It's not obvious from the inside, since there's an Al lid that covers the digital controller boards. Removal of a single screw should release it.
Ed
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Re: HP8568B battery replacement
Never mind,
Procedure starts on page 1-13 of the Installation & verification Manual - 8568B-IVM.pdf
Hi,
I have a HP8568B reporting the battery?is low. I have some 8568B manuals from Artek but I can't find anything in them?that looks like battery replacement instructions. I know I have to take a picture or transcribe the calibration measurements before I start.
Can someone guide me to the correct document number please?
FWIW, this is what I have.
9018-05833.pdf
9018-05834.pdf
9018-05860.pdf
9018-05919.pdf
9018-06816.pdf
85662A-TSM.pdf
85670A-85680B-TRM-V1.pdf
85670A-85680B-TRM-V2.pdf
8568B-IVM.pdf
8568B-PTA-2.pdf
8568B-PTA.pdf
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HP8568B battery replacement
Hi,
I have a HP8568B reporting the battery?is low. I have some 8568B manuals from Artek but I can't find anything in them?that looks like battery replacement instructions. I know I have to take a picture or transcribe the calibration measurements before I start.
Can someone guide me to the correct document number please?
FWIW, this is what I have.
9018-05833.pdf
9018-05834.pdf
9018-05860.pdf
9018-05919.pdf
9018-06816.pdf
85662A-TSM.pdf
85670A-85680B-TRM-V1.pdf
85670A-85680B-TRM-V2.pdf
8568B-IVM.pdf
8568B-PTA-2.pdf
8568B-PTA.pdf
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Re: Fume extractor recommendation
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Re: Fume extractor recommendation
Hi Radu, You don't say what your scare was, but if your doctor deduced that the lead levels in your body are high, it likely didn't come soldering circuit boards. If you have lead in your blood, look first at hygene. Lead won't penetrate your skin to any significant degree from handling it, but it will from eating with unwashed hands that have been handling lead. Don't eat, drink, or put anything in your mouth while at your bench. Don't rub your eyes! Always scrub your hands after leaving your bench. I have watched a lot of technicians chewing on wire connectors, and wire insulation and using their mouths as a 3rd hand. Don't! Lead water pipes, and fresh lead soldered joints in water pipes are an excellent way of building up the lead in your body. Workers that need to watch out for lead fumes typically work around large circuit board wave soldering machines, or in a factory making or recycling lead batteries. Fume hoods used in soldering typically are just to reduce irritation from flux smoke. -Chuck Harris On Wed, 10 Apr 2024 17:30:08 -0700 "Radu Bogdan Dicher" <vondicher@...> wrote: Hi all,
I've had a recent scare with potentially evil metals that can
vaporize - you know who you are.... - and absolutely need a good, and
hopefully affordable, solution for my bench soldering needs. And
hopefully, not just something I'll put on there for peace of mind but
have no idea if it really does anything. I really want this to work.
Are there any such things this community can recommend? I don't think
I can go used on this kind of thing, not knowing what Martian "deadly
on sight" materials the thing may have exhausted in its life. Nor I
really feel I can trust the vanilla low balling specimens on AMZ.
Being a health-related thing, I feel it kind of needs a trustworthy
solution, but my budget for this is limited.
Thank you for your input!
Radu.
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Re: Fume extractor recommendation
John, I think I'd pay you that, add money for gas, house (+ dinner and breakfast) you for a couple of nights just for the company and conversation.? Radu.?
On 4/10/24 19:48, Adam Kuzych wrote:
> you could add a 2-inch hole near your workspace, add in a dryer vent on the outside, and complete a solder fume extraction system
> with a $2K budget.
Hey,
for $2k, I might drive over from ABQ and make that hole in the wall...with all new ducting and fans...
I lived in Santa Barbara for 6 yrs and miss the mild climate, foggy nights, and luxurious landscape plants of CA.
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Re: Fume extractor recommendation
On 4/10/24 19:48, Adam Kuzych wrote: you could add a 2-inch hole near your workspace, add in a dryer vent on the outside, and complete a solder fume extraction system with a $2K budget. Hey, for $2k, I might drive over from ABQ and make that hole in the wall...with all new ducting and fans... I lived in Santa Barbara for 6 yrs and miss the mild climate, foggy nights, and luxurious landscape plants of CA.
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Re: Fume extractor recommendation
I appreciate that - and was just kind of determining it's an option, though pretty pricey new - but not used, please. The seller may have used it to make Cesium Christmas tree ornaments for all I know.?
On Wed, Apr 10, 2024 at 6:51?PM Dave Casey < polara413@...> wrote: Metcal made (makes?) a HEPA solution that can be placed on/near/under the bench. I got a used one off the auction site for a fairly reasonable price by waiting for the right deal to come along. General model number is BVX-100. There's a few different configurations (with or without the hose, and possibly with or without the HEPA-rated second filter).
Dave Casey
On Wed, Apr 10, 2024 at 8:19?PM Radu Bogdan Dicher < vondicher@...> wrote: Thank you all. Plenty of paranoia here, but backed with some reality - I have young kids and the kitchen is a literal 20 feet? from the bench. Being in CA, I have zero alternative options to reconfigure this. I at least keep my bench in the garage, so there's no chance (or they're quasi-zero) I'd recirculate this through the home HVAC system. Paranoid enough to change my slippers between home and garage, so I'd not walk any dust in the house. The way I'm wired, one just can't possibly be careful enough. I also need a hair of stress - oh, I'm the best there is at this! - to lose sleep and that's just not something I?target.? What I'm concerned about is the typical stuff in regular solder, particularly in old equipment (which I tend to collect, repair, restore, calibrate, etc.). Obviously lead, and, as far as I know, stuff in the metrology realm - my relatively new interest of excitement - can also contain cadmium in low-emf positions.?
Also, I have no way to easily exhaust to the outdoors. The garage has only two vents, one of which I've taken with an AC/heat pump unit needing to expel heat outside (of course). The high vent is open but has just about 1ppm efficiency, I'd say.?
I think what I need is at least a two-stage thing: HEPA and active carbon. I'm not obsessing over odors or VOCs as much, it's the heavy metals I'm concerned about.?
I'm close to a bunch of universities, I'll seek to inquire. Some sell affordable used lab equipment, but I know myself enough I'll not touch that stuff with a 25 foot pole.? Radu.?
I think you need to be a little more specific. Do you want a full hood and exhaust outside, or trap the fumes in filter/chemical media? Or, do you just want to get it out of the work zone and diluted?
The most volatile toxic metal that could be encountered in soldering (or brazing) would be Cd, I think. Hg would not be in solders, but any spillage would be a problem. If such spillage is likely, keep a jar of flowers (dust) of sulfur on hand to help trap the vapors - just sprinkle it on generously. Cd should be fairly stable but easy to vaporize at elevated temperatures (like soldering), so you don't want that hanging around. Once things cool down, you'll have particles of the metals like Cd and the ubiquitous Pb (and its oxide) in the form of toxic dust - that's a good thing to trap out in filters. Any Hg around will eventually evaporate away and bind with O2 or S. The sulfide is fairly benign, unless you cook it out.
Ed
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Re: Fume extractor recommendation
Metcal made (makes?) a HEPA solution that can be placed on/near/under the bench. I got a used one off the auction site for a fairly reasonable price by waiting for the right deal to come along. General model number is BVX-100. There's a few different configurations (with or without the hose, and possibly with or without the HEPA-rated second filter).
Dave Casey
On Wed, Apr 10, 2024 at 8:19?PM Radu Bogdan Dicher < vondicher@...> wrote: Thank you all. Plenty of paranoia here, but backed with some reality - I have young kids and the kitchen is a literal 20 feet? from the bench. Being in CA, I have zero alternative options to reconfigure this. I at least keep my bench in the garage, so there's no chance (or they're quasi-zero) I'd recirculate this through the home HVAC system. Paranoid enough to change my slippers between home and garage, so I'd not walk any dust in the house. The way I'm wired, one just can't possibly be careful enough. I also need a hair of stress - oh, I'm the best there is at this! - to lose sleep and that's just not something I?target.? What I'm concerned about is the typical stuff in regular solder, particularly in old equipment (which I tend to collect, repair, restore, calibrate, etc.). Obviously lead, and, as far as I know, stuff in the metrology realm - my relatively new interest of excitement - can also contain cadmium in low-emf positions.?
Also, I have no way to easily exhaust to the outdoors. The garage has only two vents, one of which I've taken with an AC/heat pump unit needing to expel heat outside (of course). The high vent is open but has just about 1ppm efficiency, I'd say.?
I think what I need is at least a two-stage thing: HEPA and active carbon. I'm not obsessing over odors or VOCs as much, it's the heavy metals I'm concerned about.?
I'm close to a bunch of universities, I'll seek to inquire. Some sell affordable used lab equipment, but I know myself enough I'll not touch that stuff with a 25 foot pole.? Radu.?
I think you need to be a little more specific. Do you want a full hood and exhaust outside, or trap the fumes in filter/chemical media? Or, do you just want to get it out of the work zone and diluted?
The most volatile toxic metal that could be encountered in soldering (or brazing) would be Cd, I think. Hg would not be in solders, but any spillage would be a problem. If such spillage is likely, keep a jar of flowers (dust) of sulfur on hand to help trap the vapors - just sprinkle it on generously. Cd should be fairly stable but easy to vaporize at elevated temperatures (like soldering), so you don't want that hanging around. Once things cool down, you'll have particles of the metals like Cd and the ubiquitous Pb (and its oxide) in the form of toxic dust - that's a good thing to trap out in filters. Any Hg around will eventually evaporate away and bind with O2 or S. The sulfide is fairly benign, unless you cook it out.
Ed
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Re: Fume extractor recommendation
Ok, there's enough information on the problem now.
Apparently, soldering 20 feet away from a cooking area, on the same level of a dwelling, even with doors in the way, with a common airspace, single HVAC, and kids around is a no-go; don't do that.
However, in a suburban garage, attached or unattached, soldering fume risks are much more manageable there. You're in California, the garage door can be kept open while soldering. Assuming the garage is owned rather than rented, and is a wood-frame building, you could add a 2-inch hole near your workspace, add in a dryer vent on the outside, and complete a solder fume extraction system with a $2K budget.
I wouldn't do that though, it's unnecessary.
Given the garage's isolation from the living space, proper ventilation, perhaps a shop fan in the garage with open door, it seems that would suffice. I use the equivalent of the Hakko 493 Smoke Absorber, and you could choose whichever model you want.
Solder and solder fumes are dangerous for anyone, particularly young children in a home environment.?
In a managed garage environment, I wouldn't expect solder and solder fumes to be terribly more toxic than a combination of fuels, oils, paints and thinners, lawn chemicals that may be stored there as well.
It is lead, not cesium. Keeping a clean garage and home and managing the risks there should resolve this problem.
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Re: Fume extractor recommendation
Thank you all. Plenty of paranoia here, but backed with some reality - I have young kids and the kitchen is a literal 20 feet? from the bench. Being in CA, I have zero alternative options to reconfigure this. I at least keep my bench in the garage, so there's no chance (or they're quasi-zero) I'd recirculate this through the home HVAC system. Paranoid enough to change my slippers between home and garage, so I'd not walk any dust in the house. The way I'm wired, one just can't possibly be careful enough. I also need a hair of stress - oh, I'm the best there is at this! - to lose sleep and that's just not something I?target.? What I'm concerned about is the typical stuff in regular solder, particularly in old equipment (which I tend to collect, repair, restore, calibrate, etc.). Obviously lead, and, as far as I know, stuff in the metrology realm - my relatively new interest of excitement - can also contain cadmium in low-emf positions.?
Also, I have no way to easily exhaust to the outdoors. The garage has only two vents, one of which I've taken with an AC/heat pump unit needing to expel heat outside (of course). The high vent is open but has just about 1ppm efficiency, I'd say.?
I think what I need is at least a two-stage thing: HEPA and active carbon. I'm not obsessing over odors or VOCs as much, it's the heavy metals I'm concerned about.?
I'm close to a bunch of universities, I'll seek to inquire. Some sell affordable used lab equipment, but I know myself enough I'll not touch that stuff with a 25 foot pole.? Radu.?
I think you need to be a little more specific. Do you want a full hood and exhaust outside, or trap the fumes in filter/chemical media? Or, do you just want to get it out of the work zone and diluted?
The most volatile toxic metal that could be encountered in soldering (or brazing) would be Cd, I think. Hg would not be in solders, but any spillage would be a problem. If such spillage is likely, keep a jar of flowers (dust) of sulfur on hand to help trap the vapors - just sprinkle it on generously. Cd should be fairly stable but easy to vaporize at elevated temperatures (like soldering), so you don't want that hanging around. Once things cool down, you'll have particles of the metals like Cd and the ubiquitous Pb (and its oxide) in the form of toxic dust - that's a good thing to trap out in filters. Any Hg around will eventually evaporate away and bind with O2 or S. The sulfide is fairly benign, unless you cook it out.
Ed
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Re: Fume extractor recommendation
Yes. This is quite obscure.
I don't know what kind of bench soldering he's? doing, or how often, but there's a range of options out there. I have a very cheap fan and filter, it went on sale for $5, and tends to bring the fumes away from me sometimes.
There's more extravagant setups for more extravagant soldering. Again, I don't know your application, or if OH&S requirements need to be followed, etc.
As one example, assuming this is hobby bench soldering, and my cheap fan and cheap filter won't do, did you look through the Hakko website, to see if there's something you'd like there?
Or is this an employer situation which is larger scope than these forums?
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Re: Fume extractor recommendation
I think you need to be a little more specific. Do you want a full hood and exhaust outside, or trap the fumes in filter/chemical media? Or, do you just want to get it out of the work zone and diluted?
The most volatile toxic metal that could be encountered in soldering (or brazing) would be Cd, I think. Hg would not be in solders, but any spillage would be a problem. If such spillage is likely, keep a jar of flowers (dust) of sulfur on hand to help trap the vapors - just sprinkle it on generously. Cd should be fairly stable but easy to vaporize at elevated temperatures (like soldering), so you don't want that hanging around. Once things cool down, you'll have particles of the metals like Cd and the ubiquitous Pb (and its oxide) in the form of toxic dust - that's a good thing to trap out in filters. Any Hg around will eventually evaporate away and bind with O2 or S. The sulfide is fairly benign, unless you cook it out.
Ed
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Re: Fume extractor recommendation
See if you can reach the facilities department at a local university.? They should be able to point you in the direction of a supplier who can meet your needs.
Peter
toggle quoted message
Show quoted text
On 4/10/2024 8:30 PM, Radu Bogdan Dicher wrote: Hi all,
I've had a recent scare with potentially evil metals that can vaporize - you know who you are.... - and absolutely need a good, and hopefully affordable, solution for my bench soldering needs. And hopefully, not just something I'll put on there for peace of mind but have no idea if it really does anything. I really want this to work.
Are there any such things this community can recommend? I don't think I can go used on this kind of thing, not knowing what Martian "deadly on sight" materials the thing may have exhausted in its life. Nor I really feel I can trust the vanilla low balling specimens on AMZ. Being a health-related thing, I feel it kind of needs a trustworthy solution, but my budget for this is limited.
Thank you for your input!
Radu.
|
What happens if you take a series of measurements, then disconnect the probes, flip the T 180 degrees, examine the result and evaluate both of them?
Harvey
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Show quoted text
On 4/10/2024 8:27 PM, jmr via groups.io wrote: I'm not sure what you mean. One can't simply look at the BNC Tee and declare that the ~120ps length of each arm is so short at 500MHz that it is irrelevant. You have to analyse how the system will achieve steady state after lots of reflection trips back and forth through the Tee at 500MHz. The Tee isn't terminated correctly at its ends, and each end has a very different termination at 500MHz because the two probe types are so different. Hence the different reflections from each arm of the Tee and hence it will take a while to settle into steady state. At steady state at 500MHz, the RF voltages seen at each probe input will not be the same. There could easily be a 2dB or 3dB difference. This is enough to destroy the integrity of the test method in my opinion.
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Re: Fume extractor recommendation
I have a few solutions, and it depends on how you balance paranoia, health, and work to do it.
The classic chem lab solution is a fume hood.
For a soldering station, you need a vent near the soldering point, a muffin fan ought to be sufficient (say 100 CFM or better), and exhaust it outside.? Chem lab solution.
What's being done for a lot of commercial soldering stations is the same, but run the air through a carbon filter.? For your own use, go to a home box store, and buy filters made for air purifiers or for litter boxes.? Use them.
If you're really really paranoid, use a shop vac with an outlet and exhaust it outside.? With that you don't need filters, you may need a welding torch because you're soldering in the midst of a hurricane.
You could use a paint fumes mask, they're suprisingly comfortable.? I've worn them for hours at a time when doing floor coating and industrial scale wood treating.
If you're curious, exhaust the air into a clump of weeds.? When they die, you know you have the right solution <grin>.
Seriously, I use a a filter with a muffin fan that's designed for craft wood burning.? It seems to be enough.
Harvey
toggle quoted message
Show quoted text
On 4/10/2024 8:30 PM, Radu Bogdan Dicher wrote: Hi all,
I've had a recent scare with potentially evil metals that can vaporize - you know who you are.... - and absolutely need a good, and hopefully affordable, solution for my bench soldering needs. And hopefully, not just something I'll put on there for peace of mind but have no idea if it really does anything. I really want this to work.
Are there any such things this community can recommend? I don't think I can go used on this kind of thing, not knowing what Martian "deadly on sight" materials the thing may have exhausted in its life. Nor I really feel I can trust the vanilla low balling specimens on AMZ. Being a health-related thing, I feel it kind of needs a trustworthy solution, but my budget for this is limited.
Thank you for your input!
Radu.
|
Fume extractor recommendation
Hi all,
I've had a recent scare with potentially evil metals that can vaporize - you know who you are.... - and absolutely need a good, and hopefully affordable, solution for my bench soldering needs. And hopefully, not just something I'll put on there for peace of mind but have no idea if it really does anything. I really want this to work.?
Are there any such things this community can recommend? I don't think I can go used on this kind of thing, not knowing what Martian "deadly on sight" materials the thing may have exhausted in its life. Nor I really feel I can trust the vanilla low balling specimens on AMZ. Being a health-related thing, I feel it kind of needs a trustworthy solution, but my budget for this is limited.
Thank you for your input!
Radu.?
|
