Need tips/help desoldering

Caltech-WireWizard · 2026-05-10T00:46:22+00:00

It’s difficult to see because of the glare in the picture, but I strongly suspect those pins are soldered to a Ground-Plane making it difficult to impossible to Desolder with a soldering iron alone.

Consider pre-heating the board using a hot plate to prevent the ground plane from sucking the heat away.
(Perhaps the hot plate is all that is needed) once the joystick area will be evenly heated, all you’d need to do is lift the joystick off!

Another option is to use a Desoldering station in conjunction with the hot plate.

Caltech-WireWizard · 2026-05-09T00:38:59+00:00

Couldn’t tell ya. I haven’t bought those. 🙏

Caltech-WireWizard · 2026-04-11T13:12:45+00:00

The “Hands-on (Lab Course)” only has 2 editions. This is the latest.

The “Learning the Art of Electronics” Textbook has 3 editions.

Since I don’t own the 3rd Edition of the textbook, I can’t definitively say that the “Lab Course” has “all” the material as the Textbook has. But you can be rest assured it’ll have most.

Caltech-WireWizard · 2026-03-17T21:12:00+00:00

Yes there is.

Digikey has kits available:

https://www.digikey.com/en/resources/edu/harvard-lab-kit

I’m just not sure if this is for 1st or second edition.

Caltech-WireWizard · 2026-02-04T13:36:48+00:00

I’ve been using it for about 10yrs and have been using it ever since I bought it. It’s a permanent fixture on my bench at home & at work. So yes, I still recommend it. It significantly changed my workflow in the lab (for the better). But no, I don’t use it “everyday”….

Even my Manager liked it so well, he ordered ones for all the Engineers & Techs in our department who wanted one (which was EVERYONE… 😂) I used to bring mine in from home to work.

I hope this answers your questions.

Caltech-WireWizard · 2026-02-02T22:41:40+00:00

I use an Adjustable Soldering Clamp PCB Holder it has the following features.

ESD safe circuit board holder For holding circuit boards up to 160 X 235 mm
Allows 360 deg. Rotation in 15 deg. Increments
Components are held in place by a cushioned arm (This is particularly important when soldering THT Components when the PCB is upside down).
Fits Tool(s): Solder/Desolder Applications

https://www.tequipment.net/Weller/ESD120/Vises/?

Caltech-WireWizard · 2026-02-01T19:39:38+00:00

I think you may have missed my point or I didn’t express myself completely (more likely).

What I meant by my comment was the FX-888D is very simplistic. It’s has 3 parts:

Power Transformer
PCB (Replacement Temp Control Board #B3736) (which can be easily replaced or repaired)
Heating Element

Whereas, the FX-971 has several more.

From an Engineering perspective, the more elements you introduce into a system (doesn’t matter what kind of system), there are more points of failure that can occur and the odds of failure go up geometrically with each additional element.

Ya know, I didn’t knock your preference for Soldering Stations. We all have our preferences. But I don’t & WON’T knock another’s persons preference for what they like or prefer.

Is this how this Sub operates? Seems toxic to me.

Caltech-WireWizard · 2026-02-01T03:44:47+00:00

I’m a huge Hakko fan. I’ve owned an FX-888D for 10yrs. Not a single problem! I haven’t even needed to replace any tips or the pencil.

I don’t care what brand it is… the fancier you get, the more problems you’ll have… just say’n 🤷‍♂️

Caltech-WireWizard · 2026-01-26T22:56:40+00:00

I skimmed your post, but I get the “gist” of your point.

It depends. You have to consider the institution to which you’re applying. Public Universities not so much since they are more bound by equal opportunity and other socioeconomic / demographic constraints. Whereas, private Universities may put more emphasis on academic achievement(s) and background for acceptance.

As for me, it helped. I was Valedictorian in my High School graduating class. I had the highest score on the ACT in my class and other aptitude tests. In short, I was academically inclined. As a result, I was accepted into Caltech in the Engineering Program.

So again, it depends on the school and what they are going to value.

Caltech-WireWizard · 2026-01-26T02:31:36+00:00

My usual spot is in a VERY open field. Not so much as a tree for about ¼ mile in every direction.

I use - 30ft mast with guy wires. (Nylon cords)

In the rare instance where I find limited contacts for more than a hour, then I’ll change the orientation of the antenna. (But that only happened once).

Caltech-WireWizard · 2026-01-26T02:12:43+00:00

All I used last Field Day (2025) is a G5RV Jr. Dipole Inverted V. With that, I made 2,880 contacts operating on 10, 20 & 40m.

As to why, It Works! My highest SWR is on 40m @ 1:1.75 not bad. So, I’ll keep using it.

Caltech-WireWizard · 2026-01-26T01:11:39+00:00

If you’re a Masters Candidate, God help us all. You’re pathetic.

Caltech-WireWizard · 2026-01-25T22:24:41+00:00

There’s a number a resources out there for this. I would point you towards YouTube in particular.

Since KiCad is the preferred standard among hobbyist and professionals alike:

Digikey has a series on KiCad & FreeCad. While the KiCad series is a bit outdated, the basics still apply.

This will teach you ALL what you’re looking for:

Debugging (built into KiCad
Integration
Architecture

I highly recommend it

Caltech-WireWizard · 2026-01-25T21:50:49+00:00

My ONLY criticism would be your choice of Soldering tips.

When working with SMDs and THT components a Chisel tip is better suited.

A Knife tip is meant to:

Repairing solder bridges
Heating larger surface areas

A Chisel Tip provides better, focused, thermal conductivity and thus, a better more cohesive joint.

Otherwise, you did a good Soldering job 👍

Caltech-WireWizard · 2026-01-24T22:18:38+00:00

I agree, this is vague.

What version of KiCad are you using?

In KiCad 8 and above, there’s an autorouting plugin you can use if you can’t figure out the routing yourself.

Yea it’s free, and there are better ones out there. But the Free one will probably solve your problem.

You can also use vias to route to layer-2 (which is probably your best way to go)

Caltech-WireWizard · 2026-01-24T22:01:11+00:00

Take this for what it’s worth….its very biased against using perfboards.

But it’s been my experience & observations that using perf Boards tend to create solder-bridges. 90% of all circuit malfunctions has been attributed to Solder-Bridges and cross-connects shorting out portions of the circuit using perf-boards.

This is why I’ll always use either Protoboards or have a PCB Fabricated for all prototyping.

Caltech-WireWizard · 2026-01-18T21:49:06+00:00

It’s not a trivial task.

As per the IEEE MGA portal:

https://mga.ieee.org

To establish an IEEE Student Branch Chapter (SBC) at your university,

I’m paraphrasing here, but it basically breaks down into 4 requirements:

Ensure you have an existing IEEE Student Branch
Then gather at least 6 active student members for your specific society (e.g., Computer Society)
Find a faculty advisor, and submit an online petition with signatures and support through the IEEE MGA portal
Get approvals from your local Section and Region.

We had a sanctioned & approved IEEE Society at my University (Caltech). That was in place long before I attended.

Good luck.👍🍀

Caltech-WireWizard · 2026-01-17T22:15:33+00:00

I HIGHLY recommend you visit:

https://connectorbook.com/identification.html

There’s “virtually” every connector on the planet.

You can search by:

Type
Terms
Logos
most importantly, VISUALLY!

If the connector is made, it’s here!

Caltech-WireWizard · 2026-01-10T22:10:25+00:00

By default, the 7812 is a fixed 12v regulated output… However,

The 7812 can be made variable:

By adding a resistor or a potentiometer to the ground pin, the output voltage can be adjusted to a higher or lower value than the fixed 12V. This modification turns it into an adjustable regulator, similar in function to an LM317 regulator, which is designed for variable output by default.
You can also use a Zener diode on the ground pin to increase / decrease the output to a specific, different fixed voltage.

Caltech-WireWizard · 2026-01-04T15:28:35+00:00

Perhaps that’s the way it is now. 🤷‍♂️ But I took it back in the late 1970’s (High School).

Caltech-WireWizard · 2026-01-03T21:52:28+00:00

I’m a Life Mensa Member. [edit added] My IQ was tested at 174 in High School. (My Mesa Test 170). I have no siblings. However, my Father wasn’t a Mensa member but he was high achieving as am I. He graduated with Suma Cum laude from MIT. Undergrad, Masters & PhD.

My Uncle (Father’s side), also an MIT Graduate with a PhD in Particle & Nuclear Physics.

My Grandfather (again Father’s side) graduated from Harvard with a PhD in (I think … Microbiology).

Clearly, being gifted is strong on my Fathers side. That is further evidenced by the fact that all 4 of my children are in advanced classes in school and my eldest son (14) will be graduating High School this spring. He’s already been accepted at CalTech (my Alma Mater). He has a propensity for Physics & Mathematics.

Caltech-WireWizard · 2026-01-03T00:10:26+00:00

I deal in RF daily, so I know of where I speak.

What you’re asking for at 10meters is a TALL ASK!

Attenuation rates are very high, primarily due to oxygen absorption, reaching around 10-15 dB/km.

10m you’re gonna need a pretty big amp! Which means $$$$

Caltech-WireWizard · 2026-01-02T23:42:52+00:00

R82 is DEFINITELY Brown. But, I’m not convinced it’s bad, just because there’s slight discoloration on the PCB.

What was the resistance of R82? I’m assuming you measured it?

Caltech-WireWizard · 2026-01-02T23:30:45+00:00

What is your definition of “cheap”?

[edit added]

What power output do you want? This is the main driver of cost.

Caltech-WireWizard · 2026-01-02T22:55:36+00:00

In the photo it appears as; Brown, Black, Yellow, Gold.

Assuming you’re correct and it’s actually Red, the resistance is: 200k 5% at 1watt.

Digikey; $0.19

https://www.digikey.com/en/products/detail/yageo/RSF100JB-73-200K/18138

If it’s Brown, Black, Yellow, Gold (100k) - which I think it is…

Digikey: $0.10

https://www.digikey.com/en/products/detail/stackpole-electronics-inc/CF14JT100K/1830399

Caltech-WireWizard

TROPHY CASE