Re: (OT) Affordable PCB fabrication (-> tariffs/US...)
I used to use PCBWay, but switched to Aisler since I am in Europe. They take KiCAD files directly and prices are reasonable. For me it is an ethical issue as well. Greater chance that EU suppliers pay their workers decent wages and that their processes are environmentally sound.
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Re: HP34401 Multimeter - 4 wire mode wont zero
I would blame the switch. Over the years, I have found front/rear selector switch problems on most of my higher resolution DMMs that have that feature, and I have deleted it where possible. If you don't need it, it is usually easy to bypass one way or another - like soldering jumpers across or rewiring around contacts, or total elimination of the switch. If you do need it, then some Deoxit treatment usually helps. Sometimes just working it lots of times (a hundred or more is not too many in some cases) can fix it. Not using the gear for long periods aggravates the dry contact situation, and so does not exercising all the system contacts with enough signal power. It's a common problem, and there are ways to restore proper operation without too much grief.
?
Ed
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HP34401 Multimeter - 4 wire mode wont zero
Hi all,
I hadn't used my HP33401 on 4 wire mode in years and I suddenly needed it to measure some current shunts when I noticed an issue.
On 4 wire mode, with the leads shorted, on 6 digit mode, it wont zero. The last 3 digits fluctuate about. Its a little more stable on the rear terminals which has me thinking its the front/rear switch rather than something else.
A search of the net seems to suggest that the switch might be the issue but I thought I'd ask here first before I go disassembling anything and poking about :)
So... is this a common error for 4 wire low ohms mode ?
Is it the switch ?
Is the switch sealed or open enough to squirt some contact cleaner in there ?
If the switch needs to be replaced, are they commonly available ?
If its not the switch, is it some other common fault ?
The meter is fine on all ranges and within spec when tested against other meters and my little transfer standard.
Any help appreciated.
thanks
Tim
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Re: (OT) Affordable PCB fabrication (-> tariffs/US...)
My boards are about 150x150mm and about 100x200mm or so, and so OSH Park is out of the question (price would be prohibitive, and worse, no volume discount...). For small projects, though - small sized prototyping boards - OSH Park is great and I always use them.?
But what I'm looking for is a place with good options (ENIG, 2oz Cu, fingers, 30deg beveling, etc.) and good pricing for low volume production. Low volume meaning 10-20 boards?at a time, not three...?
If anyone's reluctant to share?their?fabricator on the forum, please feel?free to do so offline to me directly. I'm always choosing local/domestic products and manufacturing (when possible), but in this case every place I could find that's domestic makes those riser cards simply impossible to make.? Radu.?
? ?I never send PCB orders offshore.? For "work work", my customer
requirements nearly always involve domestic production.? For prototypes,
personal projects, or other low-volume stuff I usually use OSH Park.
? ? ? ? ? ? ? ?-Dave
On 5/11/25 14:14, Radu Bogdan Dicher via wrote:
> Still hoping for some good input. Or maybe everyone's hunkering down
> waiting for this to blow over? Or maybe everyone stacked up for a smooth
> transition through some months of turbulence?
> Thank you,
> Radu.
>
> On Thu, May 8, 2025 at 12:04?PM Radu Bogdan Dicher via
> <> <vondicher=[email protected]
> <mailto:[email protected]>> wrote:
>
>? ? ?Hi all,
>? ? ?This may of particular interest to US members, but I am wondering
>? ? ?how others are handling the effect of tariffs (in particular with
>? ? ?China) on your PCB fabrication needs. Though I should say,
>? ? ?recommendations on reliable, good fabricators is likely information
>? ? ?that everyone could use.
>? ? ?I have two raiser cards I designed (for Fluke
>? ? ?instrumentation/calibrating equipment), and maybe I should just wait
>? ? ?for all this to blow over (assuming it settles somewhere different
>? ? ?than where we are), but I'd rather plan for tough times. I used to
>? ? ?use JLCPCB, but with the additional costs triggered by the tariffs,
>? ? ?I may be looking at about two or three times the cost (rather closer
>? ? ?to the latter than the former), and that just makes is unfeasible to
>? ? ?offer this product. At what hobbyists are willing to pay for
>? ? ?something like this (which, myself being one, I fully understand),
>? ? ?I'd be losing money on each one I'd make.
>? ? ?Are there some good options others have figured out where tariffs
>? ? ?are not quite so onerous?
>? ? ?I looked, for instance, at a place in India, which looks decent
>? ? ?enough and not crazy expensive - though distinctly more expensive
>? ? ?than JLCPCB - but they don't seem to have some of the capabilities I
>? ? ?want, such as beveled card edge and so on. Their features seem to be
>? ? ?about half as many as a place like JLCPCB offers.
>? ? ?There are some places in the US - and OSH Park need not apply, as
>? ? ?these are large and really need volume discounts - but they seem to
>? ? ?be very low tech in terms of getting online quotes (=0 capabilities
>? ? ?for such at what likely is the most affordable ones) and so it's
>? ? ?very hard and time intensive to investigate. But if any of you knows
>? ? ?a good, affordable and reliable place, I'd love to hear about it.
>? ? ? From what I gather, at this point, offshoring this kind of thing is
>? ? ?by far the most affordable and ultimately lucrative option.
>? ? ?particularly at hobbyist level.
>? ? ?With some places that can price me upon uploading my gerbers, I'm a
>? ? ?bit antsy about giving them away. I heard stories where once
>? ? ?uploaded, you essentially are giving away your IP and the design may
>? ? ?pop up in mass production somewhere.
>? ? ?Thank you,
>? ? ?Radu.
>
>
--
Dave McGuire, AK4HZ
New Kensington, PA
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Re: (OT) Affordable PCB fabrication (-> tariffs/US...)
I never send PCB orders offshore. For "work work", my customer requirements nearly always involve domestic production. For prototypes, personal projects, or other low-volume stuff I usually use OSH Park.
-Dave
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Show quoted text
On 5/11/25 14:14, Radu Bogdan Dicher via groups.io wrote: Still hoping for some good input. Or maybe everyone's hunkering down waiting for this to blow over? Or maybe everyone stacked up for a smooth transition through some months of turbulence?
Thank you,
Radu.
On Thu, May 8, 2025 at 12:04?PM Radu Bogdan Dicher via groups.io <> <vondicher@... <mailto:[email protected]>> wrote:
Hi all,
This may of particular interest to US members, but I am wondering
how others are handling the effect of tariffs (in particular with
China) on your PCB fabrication needs. Though I should say,
recommendations on reliable, good fabricators is likely information
that everyone could use.
I have two raiser cards I designed (for Fluke
instrumentation/calibrating equipment), and maybe I should just wait
for all this to blow over (assuming it settles somewhere different
than where we are), but I'd rather plan for tough times. I used to
use JLCPCB, but with the additional costs triggered by the tariffs,
I may be looking at about two or three times the cost (rather closer
to the latter than the former), and that just makes is unfeasible to
offer this product. At what hobbyists are willing to pay for
something like this (which, myself being one, I fully understand),
I'd be losing money on each one I'd make.
Are there some good options others have figured out where tariffs
are not quite so onerous?
I looked, for instance, at a place in India, which looks decent
enough and not crazy expensive - though distinctly more expensive
than JLCPCB - but they don't seem to have some of the capabilities I
want, such as beveled card edge and so on. Their features seem to be
about half as many as a place like JLCPCB offers.
There are some places in the US - and OSH Park need not apply, as
these are large and really need volume discounts - but they seem to
be very low tech in terms of getting online quotes (=0 capabilities
for such at what likely is the most affordable ones) and so it's
very hard and time intensive to investigate. But if any of you knows
a good, affordable and reliable place, I'd love to hear about it.
From what I gather, at this point, offshoring this kind of thing is
by far the most affordable and ultimately lucrative option.
particularly at hobbyist level.
With some places that can price me upon uploading my gerbers, I'm a
bit antsy about giving them away. I heard stories where once
uploaded, you essentially are giving away your IP and the design may
pop up in mass production somewhere.
Thank you,
Radu.
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Re: (OT) Affordable PCB fabrication (-> tariffs/US...)
I've checked the non-chinese suppliers.
4 layer PC boards, 100 mm square, (right at the price point inflexion), black, HASL.? $7.00 for the board, $4.50 or so for the color.? Shippping (DHL) roughly 20 dollars,? total cost about 6.00 per board.
OshPark would be a higher quality board (perhaps), at about $160 total.? I've found similar places that are perhaps $50 to $70 per order (I think of 5).? Other places (domestic USA) seem to be about $50.00 per board or more.
Unfortunately, and for whatever reason, the USA does not seem to have low cost PC board manufacturing.? I used to (and no longer) do double sided PC boards, no plated through holes, about 10 mil traces, toner transfer.? My designs are too complex for home production.
RIght now, I'm working through a backlog of projects and designing around existing boards.? I was fortunate enough to have put in a large order (different designs) to work with around the end of January.? I have revisions of boards that have yet to be made, so I'm waiting for now.
Apparently most of the suppliers are geared to people who make 1 inch by 2 inch boards for hobby use, and the pricing is geared mostly for corporate budgets for anything else.? $250 for a board?? Charge it to the multi-million dollar contract.
Harvey
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On 5/11/2025 2:14 PM, Radu Bogdan Dicher via groups.io wrote: Still hoping for some good input. Or maybe everyone's hunkering down waiting for this to blow over? Or maybe everyone stacked up for a smooth transition through some months of turbulence?
Thank you,
Radu.
On Thu, May 8, 2025 at 12:04?PM Radu Bogdan Dicher via groups.io <> <vondicher@...> wrote:
Hi all,
This may of particular interest to US members, but I am wondering
how others are handling the effect of tariffs (in particular with
China) on your PCB fabrication needs. Though I should say,
recommendations on reliable, good fabricators is likely
information that everyone could use.
I have two raiser cards I designed (for Fluke
instrumentation/calibrating equipment), and maybe I should just
wait for all this to blow over (assuming it settles somewhere
different than where we are), but I'd rather plan for tough times.
I used to use JLCPCB, but with the additional costs triggered by
the tariffs, I may be looking at about two or three times the cost
(rather closer to the latter than the former), and that just makes
is unfeasible to offer this product. At what hobbyists are willing
to pay for something like this (which, myself being one, I fully
understand), I'd be losing money on each one I'd make.
Are there some good options others have figured out where tariffs
are not quite so onerous?
I looked, for instance, at a place in India, which looks decent
enough and not crazy expensive - though distinctly more expensive
than JLCPCB - but they don't seem to have some of the capabilities
I want, such as beveled card edge and so on. Their features seem
to be about half as many as a place like JLCPCB offers.
There are some places in the US - and OSH Park need not apply, as
these are large and really need volume discounts - but they seem
to be very low tech in terms of getting online quotes (=0
capabilities for such at what likely is the most affordable ones)
and so it's very hard and time intensive to investigate. But if
any of you knows a good, affordable and reliable place, I'd love
to hear about it. From what I gather, at this point, offshoring
this kind of thing is by far the most affordable and ultimately
lucrative option. particularly at hobbyist level.
With some places that can price me upon uploading my gerbers, I'm
a bit antsy about giving them away. I heard stories where once
uploaded, you essentially are giving away your IP and the design
may pop up in mass production somewhere.
Thank you,
Radu.
|
Re: (OT) Affordable PCB fabrication (-> tariffs/US...)
Still hoping for some good input. Or maybe everyone's hunkering down waiting for this to blow over? Or maybe everyone stacked up for a smooth transition through some months of turbulence?? Thank you, Radu.?
On Thu, May 8, 2025 at 12:04?PM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Hi all,
This may of particular interest to US members, but I am wondering how others are handling the effect of tariffs (in particular with China) on your PCB fabrication needs. Though I should say, recommendations on reliable, good fabricators is likely information that everyone could use.?
?
I have two raiser cards I designed (for Fluke instrumentation/calibrating equipment), and maybe I should just wait for all this to blow over (assuming it settles somewhere different than where we are), but I'd rather plan for tough times. I used to use JLCPCB, but with the additional costs triggered by the tariffs, I may be looking at about two or three times the cost (rather closer to the latter than the former), and that just makes is unfeasible to offer this product. At what hobbyists are willing to pay for something like this (which, myself being one, I fully understand), I'd be losing money on each one I'd make.?
?
Are there some good options others have figured out where tariffs are not quite so onerous??
?
I looked, for instance, at a place in India, which looks decent enough and not crazy expensive - though distinctly more expensive than JLCPCB - but they don't seem to have some of the capabilities I want, such as beveled card edge and so on. Their features seem to be about half as many as a place like JLCPCB offers.?
?
There are some places in the US - and OSH Park need not apply, as these are large and really need volume discounts - but they seem to be very low tech in terms of getting online quotes (=0 capabilities for such at what likely is the most affordable ones) and so it's very hard and time intensive to investigate. But if any of you knows a good, affordable and reliable place, I'd love to hear about it. From what I gather, at this point, offshoring this kind of thing is by far the most affordable and ultimately lucrative option. particularly at hobbyist level.?
?
With some places that can price me upon uploading my gerbers, I'm a bit antsy about giving them away. I heard stories where once uploaded, you essentially are giving away your IP and the design may pop up in mass production somewhere.
?
Thank you,
Radu.?
|
HI,
?
I have a HP8595E with a problem of power supply. The power supply doesn't start when the line switch is on, all the power-supply LEDs remain off. I check the shematic diagram and i find a diode failed (short circuit) CR306 (HSMS-2800) on the PSU control board.?
I don't understand the function of the AOP U303D on the shematic diagram, so i unsoldered this diode CR306 and i don't replace it immediatly because i didn't have any. I then tried without this diode and the power supply was running well.?
?
?
?
VSTBY is 15V, the voltage on the pin 10 U303D (KS_EN) is about 6V (VRAIL is about 320V and the resistor divider 632K and R311 12K1 provide this voltage). The voltage on pin 11 U303D is 7,5V by the divider resistor R309/R310 100K/100K. So the output pin 13 of U303D is Hi arround 13 V. When the switch line is on, the PWRON_L is connected to the FB_GND and so the there is no signal on TR301-7 and on the? anode of CR302, voltage on pin 6 of U303B is 0V the power supply is on.?
With these diode CR3036 on short circuit it was impossible to start the power suply because event if? there is no signal at the output of T301-7 and the anode of CR302, the output of U303D maintains a voltage on pin 6 of U303B and pin 8 U303C.
So what is the function of this U303D ? in my opinion the output of U303D never gone 0V and even if this output is at 0V (it would be possible if the +VRAIL failed) what? would be the desired function knowing that the shutdown of the power supply is conditioned by a hight level on the anode of CR306. If anyone understand the interest of this part of the diagram U303D I would apreciate the answer.
Thanks to the person who put this diagrams online.
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Re: HP8756A possible CRT subs?
For a 1345A replacement look at a Symmconn labs Newscope 5
?
Robert.
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Re: Clorox Wipes & Magic Erasers
I wouldn't use either Clorox (bleach), or magic erasers (abrasive).
?
Would start with warm soap and water. If grimy, I would use Joy dish soap or Dawn dish soap.
?
If not grimy, I think car wash soap would be gentler/less residue, and you can go down to gentle woolite detergent if there's really no grease there.
?
Then some of these specific cleaners mentioned earlier sound worthwhile . I've used Fantastik on hundreds of grimy Motorola radios before, without any damage. Spray-Nine and Windex are a no-go.
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Hello Folks,
thank youse all for the help. Now let me see if I can get the unit in ;)
As for the ECAL: no need for that, here. We do a HissCAL (tm) instead, allowing Annette to bleed off excess energy in a more productive way than hissing at me or my other workers.
;) ;) ;)
Tam
--
With best regards
Tam HANNA
Enjoy electronics? Join 21k4 other followers by visiting the Crazy Electronics Lab at
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Re: Clorox Wipes & Magic Erasers
I like foaming cleanser (amberclens or equivalent) for textured surfaces. Not much else gets into the creases without leaving a residue.
?
For plastics, there's a set of polishes used by pinball maintainers.
?
Novus 1 is an antistatic cleaner. The other two will polish scratches out.
?
3M have a product called finesse-it which is a petroleum-based polish that some people prefer. I haven't used it extensively.
?
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Re: HP8756A possible CRT subs?
Interesting. Scalars are MUCH quicker to use and my first choice. I have 8720, 8510C, 8722A, even old 8410C stuff, but I hardly use them because I rarely need to measure phase.
My go -to is an 8757C with a 83650A sweeping synthesizer - most handy with a plotter to capture S21 work. VNA's are great, but tedious.
Jeff Kruth
In a message dated 5/10/2025 4:22:15 PM Eastern Standard Time, yrrah@... writes:
?
Easy: if you do not have a vna to 20+ GHz for example. Like me.... I use it quit often.
Harke
On 10/05/2025 21:29, Robert G8RPI via groups.io wrote:
What would you use a scalar analyser for these days?
The only place I've seen them still in use in recent years is older microwave antenna measurement ranges. Those were old existing facilities.
?
Robert.
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Re: HP8756A possible CRT subs?
Easy: if you do not have a vna to 20+ GHz for example. Like
me.... I use it quit often.
Harke
On 10/05/2025 21:29, Robert G8RPI via
groups.io wrote:
toggle quoted message
Show quoted text
What would you use a scalar analyser for these days?
The only place I've seen them still in use in recent years is
older microwave antenna measurement ranges. Those were old
existing facilities.
?
Robert.
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Re: HP8756A possible CRT subs?
Yes Tom, I have done CRT rejuvenation before with some success. About ten or so years ago I did experiments on some junkers, and an actual fix on a Tek 576 CT that's still working well.
?
I was hoping to not have to fool around with all the details and grief, just doing a quick swap and see what happens.
?
After some more investigation I found that the 8756A uses an HP-made OEM type display - a 1345A apparently. I have found the manual for that, so now I can at least work on the display aspects. It's quite complicated with built-in digital storage, vector drawing, and character generation. With proper info (and time and patience) I can find out what the deal is - maybe the CRT is OK after all, just way out of adjustment or with a part failure in the circuits. At least I should be able to ID the CRT now and compare against ones in other HP gear, just in case.
?
Ed
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Re: HP8756A possible CRT subs?
What would you use a scalar analyser for these days?
The only place I've seen them still in use in recent years is older microwave antenna measurement ranges. Those were old existing facilities.
?
Robert.
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Re: Clorox Wipes & Magic Erasers
I used to use Meguiar¡¯s Mirror Glaze plastic polish for polishing jet aircraft canopies in the Air Force. The product came in varying grades of abrasiveness all the way down to a very fine cleaner used as the last application. I still have a set of this polish and do use it when working on stubborn panel stains and such. It looks like they now have moved it into the PlastX group of cleaners.
Greg
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Re: HP8756A possible CRT subs?
Hi Ed,
?
ever thought of regenerating the CRT cathode?
Might be easier than replacing the unit.
?
Tom
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HP8756A possible CRT subs?
I fired up this 8756A I've had for many years and never used because it didn't seem to work. The CRT is very dim and with poor focus. I tried to tweak it up a bit by guessing at various pots in the display module, with little improvement. I think the CRT is at its EOL.
?
I can't find any (free) service manuals or info to work on it or even ID the CRT, and I don't think it's worth buying any since I'm very near to getting rid of it anyway, unless I see some potential goodness.
?
Does anyone happen to know if the CRT is the same as in the 8566's IF/display unit (85665 I think)? I have some of these so it might be any easy swap if so, then I could see if it can be fixed. The faces appear to be the same size, and both are electrostatic deflection with drawn graticules, and similar application, so it would make sense to use the same CRT. I know that the over the years the 8566 displays had two different possible CRTs (and support HV circuitry) used - I'm hoping for either one to be a possible sub.
?
Ed
?
?
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HP-8903A Audio analyzer - Un-stable output below 0.5865V (3-relay OSC Board)
Hello All,
Need help on HP-8903A, it took more than 2 years fighting,
1.it came with an ERR=18
after checked, -15V rail had bad regulator A11U2 and shorted filter cap C02, an easy fix.
?
2 after few days playing, system suddenly did not respond to keyboard.
found A8 CPU board , the most CPU pins were black and rusted,?
easily crashed when touch, by soldering? IC? directly to another CPU socket with fly wires. then seat back to original socket,
it run perfectly again.
3. another few days running testing with GPIB program, thank you very much for great work from Mr. Pete Millett.
Software did control the measurement and actions,?
however the voltage reading something wrong, (not taking notes clearly for this issue)
through the block diagram, the RMS voltage measurement related with A4 board,
follow troubleshooting sheet A4 1-3, confirmed no DC checked on A4TP1,? A4U5 was suspicious.
Replaced with a new LM301AH, it run good again.
?
4.few days later, the THD reading getting high just after power On, after 20mins warm up, the THD reading back to normal.
after long chasing/measurement on board, and took one lead out to measure film caps.
finally found out C45 3uf/100V reading is good, but leaking.
New film cap was replaced, it read quick again.
?
Rainy day? always after sunny days..
?
5.One more issue recognized, when OSC. output lower then 0.5865V, the voltage reading and THD was not stable, up/down slowly.
it took long time verify this issue,?
Since not every time encountered, but says > 70% happened.
?
I can't locate the issue either from Osc. board A6 nor Atten. Board A5,?
Until I got second unit in very reasonable low price,?
luckily, A6 Atten. board was confirmed defective board, after several swapping tests.
?
6. issue is my A6 board is "3 relay" version, can't find matched schematics/troubleshooting yet.
the A6 board marked "08903-60105 / A-2242-10", Would someone could instruct where to have it.
A6 board from second unit is "2 relay" version matched the service manual.
?
almost last mile to go, any hints would be super appreciated!
?
Chen-shen
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Anders
Dave McGuire