# A litany of dumbassery **URL:** \ **Category:** Uncategorized\ **Created:** [April 4, 2020, 9:42pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526 "2020-04-04T21:42:52Z")\ **Posts on this page:** 20\ **Page:** 18
**Author:** ![Jos](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/jos/32/151_2.png) [@Jos](https://lookmumnocomputer.discourse.group/u/Jos)\ **Post date:** [January 1, 2021, 6:43pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/341 "2021-01-01T18:43:23Z")
Why waste a thousand words: ![20201231_162956](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/6/6802bdd12f04a0107d6314b56e37a1530a6f8d90.jpeg) ---
**Author:** ![eric](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@eric](https://lookmumnocomputer.discourse.group/u/eric)\ **Post date:** [January 3, 2021, 8:47am UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/342 "2021-01-03T08:47:42Z")
What’s that hot plastic smell ? Too focussed on getting that ground pad on the pot heated up… (man are they hard to get up to temp with my iron !) ![x1](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/e/e10d6183e56c61c879b23fe7273d0765ad28222e.jpeg) There, I fixed it ! ![x2](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/1/13a19c01c9629a9f3db2bb725c59b23ef825f0d5.jpeg) Works perfectly… ![x3](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/8/8a63082ce58b18c1f1142c0c2f517f722e7b3d0f.jpeg) Still need to reflow that solder joint… ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [January 3, 2021, 10:03am UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/343 "2021-01-03T10:03:45Z")
I think we all vae the T-Shirt for that one. ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [January 3, 2021, 10:04am UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/344 "2021-01-03T10:04:53Z")
Don’t worry too much about the mounting legs. Rob ---
**Author:** ![eric](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@eric](https://lookmumnocomputer.discourse.group/u/eric)\ **Post date:** [January 3, 2021, 10:25am UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/345 "2021-01-03T10:25:10Z")
I won’t even try the two “clips” with my current iron… ---
**Author:** ![analogoutput](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/analogoutput/32/29663_2.png) [@analogoutput](https://lookmumnocomputer.discourse.group/u/analogoutput)\ **Post date:** [January 3, 2021, 1:00pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/346 "2021-01-03T13:00:06Z")
Love it when I carefully solder everything in order from lowest to highest, saving the headers and electrolytics for last, and then realize there’s parts on the other side that will be the lowest of all… ---
**Author:** ![eric](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@eric](https://lookmumnocomputer.discourse.group/u/eric)\ **Post date:** [January 3, 2021, 1:29pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/347 "2021-01-03T13:29:09Z")
That’s a recursive thing ! When you solder “the other side” first, you’ll be back to the same problem when soldering “the _new_ other side” second… ---
**Author:** ![devicex](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/devicex/32/28_2.png) [@devicex](https://lookmumnocomputer.discourse.group/u/devicex)\ **Post date:** [January 3, 2021, 7:03pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/348 "2021-01-03T19:03:25Z")
been there done that and fingers to . ---
**Author:** ![BlackDeath](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/blackdeath/32/7644_2.png) [@BlackDeath](https://lookmumnocomputer.discourse.group/u/BlackDeath)\ **Post date:** [January 11, 2021, 9:40pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/349 "2021-01-11T21:40:05Z")
Big fucking blob of fucking goddamn solder dropped right in the middle of my too-complicated-for-my-first-stripboard project and I don’t know how to get it out and there’s wires in the way and goddammit shitting fucking fuck goddammit! ---
**Author:** ![Riggidyboo](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/riggidyboo/32/10_2.png) [@Riggidyboo](https://lookmumnocomputer.discourse.group/u/Riggidyboo)\ **Post date:** [January 11, 2021, 9:58pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/350 "2021-01-11T21:58:53Z")
I took a hammer to my first SMD project, but I don’t recommend that. Dragging the tip of your soldering iron between the copper strips should pull the solder off to the sides, or heat the blob up and pull down the line. ---
**Author:** ![Farabide](https://avatars.discourse-cdn.com/v4/letter/f/ecc23a/32.png) [@Farabide](https://lookmumnocomputer.discourse.group/u/Farabide)\ **Post date:** [January 11, 2021, 10:01pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/351 "2021-01-11T22:01:45Z")
Heat the solder then quickly slaap the stripboard on the edge of a table. Solder side down! Repeat until the excess is gone then go on eBay and invest in a solder sucker 🙂 ---
**Author:** ![devicex](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/devicex/32/28_2.png) [@devicex](https://lookmumnocomputer.discourse.group/u/devicex)\ **Post date:** [January 11, 2021, 10:52pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/352 "2021-01-11T22:52:18Z")
yep the heat and slap works good even to clear through holes that get plugged with solder. ---
**Author:** ![Dud](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/dud/32/610_2.png) [@Dud](https://lookmumnocomputer.discourse.group/u/Dud)\ **Post date:** [January 11, 2021, 11:15pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/353 "2021-01-11T23:15:12Z")
do what you can and maybe put it aside while you buy a desoldering pump ---
**Author:** ![BlackDeath](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/blackdeath/32/7644_2.png) [@BlackDeath](https://lookmumnocomputer.discourse.group/u/BlackDeath)\ **Post date:** [January 12, 2021, 1:30pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/354 "2021-01-12T13:30:12Z")
This actually worked better than expected, then I cut into the traces with an exacto knife. Seems like the rows are separated, if just barely. Thanks for the tip! I think the lesson I learned here is one that nobody can really tell you about. I’m building this: ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/3/34b870f8398ee9a76d47966abbae13bebaf99c79.jpeg) My issue was with those long vertical wires with multiple stops down the middle. I did it with daisy chaining a few small wires, leading to messy junctions. I think I should have done one long wire with shorter wires coming off of that one for the connections in the middle. Oh well, live and learn. We’ll find out if it works when the LMs show up, should be any day now. 🤞 🤞 🤞 ---
**Author:** ![BlackDeath](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/blackdeath/32/7644_2.png) [@BlackDeath](https://lookmumnocomputer.discourse.group/u/BlackDeath)\ **Post date:** [January 12, 2021, 1:31pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/355 "2021-01-12T13:31:56Z")
I’ve also got some pre-dumbassery to ask about - Can I put a potentiometer on a + (or actually maybe -)12V power connector? I thinking that maybe if I dropped the whole power inputting to the circuit, it might decrease the frequency of all three oscillators at the same time… a bit like a “whammy bar” on a guitar. Is this a terrible idea? ---
**Author:** ![Farabide](https://avatars.discourse-cdn.com/v4/letter/f/ecc23a/32.png) [@Farabide](https://lookmumnocomputer.discourse.group/u/Farabide)\ **Post date:** [January 12, 2021, 1:50pm UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/356 "2021-01-12T13:50:28Z")
Take a look at Sam’s central detuner with the SSO banks. Not sure if this will starve in the way you think. No harm in trying. ---
**Author:** ![zorch](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/zorch/32/5586_2.png) [@zorch](https://lookmumnocomputer.discourse.group/u/zorch)\ **Post date:** [January 13, 2021, 12:25am UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/357 "2021-01-13T00:25:44Z")
![16104974072151363303786770619900](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/8/8efc448b900ddc5c6edbcd2d5d93e139298fc29e.jpeg) Lookin good! ![16104974517888541249198367363674](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/9/98a49a499e060a7ff0461e7abb66dddefcdf60dd.jpeg) Not so good. I have to either take it all apart or cut slots in my rails. 🙄 ---
**Author:** ![Farabide](https://avatars.discourse-cdn.com/v4/letter/f/ecc23a/32.png) [@Farabide](https://lookmumnocomputer.discourse.group/u/Farabide)\ **Post date:** [January 13, 2021, 12:47am UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/358 "2021-01-13T00:47:13Z")
That’s why the good lord made gaffa tape. Looks brilliant! ---
**Author:** ![analogoutput](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/analogoutput/32/29663_2.png) [@analogoutput](https://lookmumnocomputer.discourse.group/u/analogoutput)\ **Post date:** [January 13, 2021, 1:14am UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/359 "2021-01-13T01:14:08Z")
You mean a pot in series on the +12 V rail as a rheostat? I might be thinking about this all wrong, but: The LM358 needs 3 V minimum, so with a 12 V supply the maximum voltage drop across the pot would be 9 V. Each LM358 draws approximately 1 mA, so the circuit probably draws roughly 5 mA. That means the maximum value of R is 9 V / 5 mA = 1.8k. Using a 1k pot would get you a range from 7 to 12 V. A 500R pot would only get you 9.5 to 12 V. A 5k pot would take you from 12 V to down below that 3 V minimum. Pots typically are rated for 1/8 W. (Check the datasheet.) With a 1k pot that corresponds to 11 mA maximum (at any wiper setting), so 5 mA should be safe. For a 5k pot the maximum current would be 5 mA, so if you really were drawing 1 mA per LM358 you’d be on the edge of burning out the pot. So I _think_ a 1k pot could work. Smaller wouldn’t give you much voltage range and larger might put the pot at risk, unless you find a higher power rated pot. (If you use a 1k pot and it goes up in smoke, I will delete this post and deny everything.) ---
**Author:** ![juggle](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/juggle/32/6100_2.png) [@juggle](https://lookmumnocomputer.discourse.group/u/juggle)\ **Post date:** [January 13, 2021, 5:45am UTC](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526/360 "2021-01-13T05:45:56Z")
Well…that explains why my second DIY 3340 VCO isn’t working: ![20210112_223409](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/e/ef00fa6b21b0caefcfa9aa8463c9c80fa29818ce.jpeg) 🤦‍♂️ I don’t remember how this happened. I had this VCO working, then built a second with board mounted pots…and I remember having both of them working at one time so I don’t think I just stole the wiring from this one for the other one. And apparently when I started populating the new case I shoved it in there without noticing that it no longer had any of the jacks wired. At least it will be an easy fix! [Previous page](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526.md?page=17) [Next page](https://lookmumnocomputer.discourse.group/t/a-litany-of-dumbassery/526.md?page=19)