Not at all convinced by this . .? ??

I use an antistatic mat as my bench covering at all times, grounded, linked to PSU, linked to soldering iron.? ?It runs to the front of the bench so my arms rest on it automatically but for known super-sensitive work I wear a strap too.? ?

They wear out in time but the next is already in the cupboard.? ?ps their surface resistance is very high but a good GigOhm meter or tester will see it over a few inches and a HV insulation tester easily for a periodic test.? Their aim is to drain static slowly, do no harm to live circuits parked on them and also be non skid . .?

Lloyd,

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The components were produced on a QIDI Plus 4 printer, utilizing a mix of PLA and PLA-CF, with plans to potentially print another unit in PPS-CF for enhanced durability. The PLA parts were printed using a fully calibrated .4mm nozzle, following the Orca slicer calibration process, which was also applied to the PLA-CF filament. For the front panel, a .2mm nozzle was used with PLA-CF to achieve sharper lettering and reduce filament layers. I included a photo of the raw front panel with primer to illustrate the clarity of the lettering, although the white paint application slightly distorted the letters. After calibrating the filaments and printing the parts, a self-etching primer was applied to reveal the layer lines, followed by a quick wet sanding with 400 grit and a layer of autobody spot filler, which was also sanded with wet 400 grit. Once the layer lines were filled, another primer coat was applied, followed by wet sanding with 1000 grit and two to three coats of green paint, sanding between each layer. After the final green paint coat dried, a matte clear coat was added to seal the surface and prevent the white paint for the lettering from contaminating the green paint.
Next, I then applied white paint to the lettering wiping clean with a dry towel this left some paint smearing on the part surface which was sanded off once dry with wet 2000 grit paper. Then a final coat of clear matte finish and phew its done.

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73, Dave

W6MQI

I recently ordered a qty of board assys from JLCPCB which pushed the $800 limit but FedEx shipped the order through Incheon, South Korea.?

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73 Kees K5BCQ

Thanks for the reply, Ron!

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Yes, I really meant C31. I think what happened is I actually broke half of the component off the board with the clamp I use for soldering. It was clamped on the side of the board nearest C31 and I wasn't careful when I clamped it and broke half the component right off the pad.?

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Since I made this post, I actually gave it a little tug with a plastic tweezers and the whole capacitor came right off the board. I think I lifted the solder pads right off the board when I attempted my "repair." I had the soldering iron cranked up to max temp to desolder those big headphone jack pads and I didn't turn it back down when I patched C31.?

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So, I've created a bit more of a headache for myself now.?

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But: It gets even worse. I decided I'd make a temporary repair by jumpering a thru-hole capacitor between R41 and the nearest neighbor to C31 and I lifted R41 right off the board too. Burnt the SMD pads right off again, even with lower power. I guess I'm terrible at SMD repairs.

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Any suggestions for repairing this? I guess I need to find a way to replace R41 and C31 without any pads left now. I could scrape away some solder mask and try to wire a few thru-hole components in series, but for now I've just given up.

I have the lovely task of testing all my company's esd surfaces and continuous static monitoring devices.??

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A couple of things I read here need to be said.?

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1. paper (Manila folders included)? is a static generating material.? It will create a static charge just lifting it off of cirtain material.? keep it 12"+ away from any static sensitive device.?

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2. the 1mohm resistor Don Brant mentioned is important for the purpose of allowing static charge to go to ground somewhat slowly in order to not make a spark.

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If you're work surface is properly grounded and you are not wearing a wrist strap with 1mohm resistor embedded,? then your charge will travel on the work surface to ground and may effect anything lying on the that surface.? we even have to remove all static devices from the surface before doing a surface test for this reason. Profe of receipt...I had a lightning strike that went across my metal desk and blew avhf/uhf radio up that was not even connected. Okay, maybe lightning is overkill example of static discharge but the principle is the same.?

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I'll shut up now.??

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regards,
Bryan, N0LUF

There's a difference between minimum soldering iron and the? 'OMG I should have bought this 10 years ago' soldering Iron you'll buy eventually.

While components and PCB's are getting smaller the arrival of on-PCB heatsinking areas and multi layer boards has upped the challenge for a good joint without component damage (= Rapid heat transfer and done )?

I use a 90W temperature controlled Weller with 2.5mm chisel bit 99.9% of the time.? ?It has ridiculous, stable, heat generation and transfer capabilities and makes great joints quickly when a smaller /less powerful iron would keep me waiting (And frying the associated components for 30 - 60 seconds at a time.? It also has a useful LCD Display showing how much power (=heat transfer) is actually going into the joint which helps improve technique.?

I use 325°颁? for Leaded and 355°颁 for unleaded.? ?Due to high power and temperature control of my iron these do not need fiddling with to try to build up 'extra heat' in the 'too small iron'?

If you think you will be in this hobby in 3 years or more spend the money on a good one now? . . .?

I do have a '60W' Chinese temperature controlled iron in the car for unexpected emergencies. . .? ? ?It often does the job but but not always and can even end up stuck to really large solder areas which is fairly awkward? . . .? ?It would probably let me assemble a QRP Labs kit though but there's 0% chance I'd want to by choice with a better one on the bench.


A paint stripper heat gun will be disaster on PCB's? - again a decent one will change your life early on reworking SMD boards

I have been using low-band QMX with 50W amp for several months with 018 software. Today I uploaded the .027 firmware and that process went as normal, but afterward the QMX does not transmit. Tests look all OK (bias, SMPS voltages,supply 8.9V, Tx voltage 7.5) but on transmit 'T' the power is 0 or flickering 0.1W, but a valid 1.1 SWR (dummy load). The power meter on the dummy load does indicate a small output, about 100 mW.

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I tried reloading the .018 firmware, but still no TX.? I tried a factory reset from the menu. Then I used the jumper to force bootloader reloaded .027 firmware, went through replacing settings and condition is still only tune level output.

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I also have a high band QMX and I uploaded the .027 firmware to it a few days ago with no problems and have been using it successfully on 10 and 15 which has be quite open lately. This success led me to put the .027 firmware into the low-band rig.

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You don't need to buy a new iron, though it would speed up your work a bit. The ideal soldering iron gets hot enough for the task at hand, and quickly reheats after soldering a joint; 60W lets you do that more quickly, and a low mass tip also helps with that speed.

On Tue, Feb 25, 2025 at 11:42 AM, Don VE3IDS wrote:

Are those cheap blue silicone soldering mats that are advertised as ESD protection really effective at protecting from ESD or are they just heat resistant??

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Good mats will have a snap or banana jack connection for grounding; either the mat or the grounding means will include a 1Meg resistor in series.

Without a ground where will the charge go?

73, Don N2VGU

On Tue, Feb 25, 2025 at 08:42 AM, Don VE3IDS wrote:

Are those cheap blue silicone soldering mats that are advertised as ESD protection really effective at protecting from ESD or are they just heat resistant??

While I don't have the means to test it properly, the one I have linked above has the following description:

Just finished a U3S for a friend. Question is about timing. From cold start, it has taken up to 20 minutes for the GPS time (18 seconds 'fast') to be corrected to UTC time. Without the super capacitor, this happens every time power is interrupted. Hans stated in the manual that you really don't need the super capacitor for amateur use. However, that would mean that WSPR doesn't cate if you are 18 seconds fast. Is this correct? And if WSPR doesn't care, shouldn't the super capacitor be a necessary part of the QLG2?

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73, Dan? NM3A

Are those cheap blue silicone soldering mats that are advertised as ESD protection really effective at protecting from ESD or are they just heat resistant??

On Tue, Feb 25, 2025 at 05:17 AM, spaine wrote:

A good ESD work surface is conductive

The correct word here would be "dissipative" - something that quickly dissipates static charge, but has a very high resistance to normal electrical currents.??

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As Allison said, inexpensive ESD mats are safer, and they are easy to get and use.? And even the $20 ones on Amazon, complete with wrist strap, will last a very long time.? I encourage all assemblers of qrp-labs kits to get one and use it.

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Stan KC7XE?

Greetings,

I have a QMX kit on the way. I notice the recommended soldering iron is 60w and the one I have is 40w so I will have to buy something.

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There seem to be hundreds listed on Amazon and most have controllable temperatures.?

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From what I remember from my reading, some components need higher temperatures and others lower temperatures for soldering but I have not seen actual? temperature numbers.

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Do you have any recommendations for temperature numbers either in C or F?

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Some of the soldering stations listed in Amazon have a heat gun as well as a soldering iron. I already have a paint stripper heat gun I use for heat shrinking. Is the smaller unit on stations useful?

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Do you have any specific stations listed in Amazon that you recommend?

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Thanks so much for any suggestions you may have.

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Back in my younger days, I built many Heathkits. This kit will be challenging because of its compact nature.

Jim

I regard that as a potential deathtrap.

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ESD mats are cheap and far safer and will not ground you?

if you playing with line voltages or higher (tube gear).

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Also it has great potential to create a short on the

back or front of most circuit boards.

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Allison
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Post online only,?
direct email will go to a bit bucket.

A good ESD work surface is conductive, but not too conductive. ?That way it maintains equipotential between your work, your wrist strap, and your iron, but any inadvertent discharge that does occur is dissipated slowly and safely. ?I like these cheap conductive cardboard mats from Desco--they're intended to be disposable for industrial use, but last forever at home and take soldering heat well. ?The one in the photo was about $10 from Newark here in the US.

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Scott

U3s was here in 9 days and the enclosure from china went thru customs as usual and arrived on day 16. No tariff issue. Not bad.

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regards,
Bryan, N0LUF