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General Technical Chat / Re: Good soldering flux?
« Last post by wraper on Today at 11:21:11 pm »
...But you left off my favorite flux, TF5000, so I'm going to have to ask you to do that over...  hah!
I tried it quite a while ago. Cannot call it anything better than useable. Nothing exceptional in soldering properties and IIRC it was slightly conductive before reflow.
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I made my own AQ monitor using a sensor that was a rebadge of the Plantower sensor that those devices use. By default they just chatter their readings over the 3.3 V TTL level UART pins. The data format is simple, https://aqicn.org/air/sensor/spec/pms5003-english-v2.3.pdf. If you have USB-UART interface, you can read the raw data frames in a terminal viewer.

They're susceptible to an early death if the fans pull debris into the measuring chamber ... in my case, probably cat hair. They just permanently read the max reading for me. That's probably why the PurpleAir monitors have redundant sensors, mounted with the fans pointing down so things don't settle in.
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Test Equipment / Re: SDS800X HD Bugs/Wanted Features
« Last post by 2N3055 on Today at 11:20:23 pm »
It's enough now, this thread is actually intended for a factual exchange...

The last 10 posts could be condensed down to the two posts of rf-loop giving me what i have asked for, and me thanking him. :-//

And as i already wrote, you are welcome to ignore me.  ::)

No, we won't ignore you.
You are an spamming all of us with your stupid posts.
You start behaving like a normal human being or go away and bother other children in your kindergarten.
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RF, Microwave, Ham Radio / Re: vacume caps
« Last post by vk4ffab on Today at 11:18:15 pm »
DUDE please stop with your endless strawmen arguments showing that you are an internet expert. Go learn to read and understand things.

So, I'm not sure, what I should learn and understand exactly in your opinion?


Reading and comprehension of what is written. Yeah your technical knowledge is superior to mine, heck lots of people in this thread can make that claim. But I am the only one who asked the OP for clarification of exactly what he was asking rather than assume, because i am not an expert and I am not a mind reader and I do not have all the answers. Reading and comprehension mean sometimes you have to ask questions to better understand what is actually being asked.

The context is for use in an l match atu.

Fwiw my lashup franken doublet is working fine,the atu l match started off with a 1000pf wide spaced air variable,This was ok matching 80+40m but had a min c that was too high,i removed plates untill it was circa 300pf,This works well >40m too 10m,for 40+80m i have 1400 of silver mica caps switched in paralell with the variable,i just thought the vacume cap would alow better efficeincy+ tuning over the fixed silver mica?.The antenna is used mostly for interG nvis contacts,getting on 80m living in a small flat in a concervation area was difficult!.

Now the OP's question was rather open ended, but he clarified things even before you started posting about magnetic loops. My comments were in the context of the above 2 posts. That the OP was building an L match and he had a doublet. Even if you had read the first of those comments, Post 4, before you made Post 5, you would have understood the context of the thread. Again reading and comprehension. Do you use L match tuners in magnetic loop antenna? Not that I am aware of, but they do use a capacitor, not a fixed capacitor as the OP was talking about but a variable one. What is being asked by the OP can be derived from the context of the thread and thus the context of the answers being given.

If you had read and understood the thread, you might have commented in a way that helped the op rather than looking for something wrong on the internet.
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General Technical Chat / Re: Custom "R-core" transformers on ebay
« Last post by coppercone2 on Today at 11:16:48 pm »
I would like to see a X core transformer. four windings, no purpose.
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FPGA / Re: FPGA Bluetooth/WiFi Project
« Last post by Foxxz on Today at 11:16:19 pm »
Is this a learning exercise? Why is an FPGA being used at all? Add a clock display (and LED?) to the arduino. Can't help much on the BT stuff. The "nRF Connect" app on android is a good way to freehand BT communications without writing your own app.
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I think you need to take a step back and consider what you are trying to do.
I'm doing a critical CERN-like experiment so need the most sensitive instrument like they do at the Large Hadron Collider. Remember the movie Interstellar where they need to collect data to finish the equations of quantum gravity and save the future. My experiment is like it.
This is a red herring!  The poster is using the instrumentation to detect bioelectrical signals like EEG, EMG and ECG.  They are definitely NOT performing a particle physics experiment!

That's not to say their experiment is any more or less in value to the scientific world.  Just that from an engineering technical perspective, the poster is dealing with human biosignals.
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Microcontrollers / PCB design question (crystal end ATmega)
« Last post by tiger80 on Today at 11:12:52 pm »
Hello everyone  :)
Ok so I have finished laying out a board. I have an ATMega128A running with a 14,7456MHz crystal. The board has two layers and I have chosen the top layer and bottom layer as the ground plane (GND).
Following design guidelines, I have kept the trace length between the crystal and the AVR minimal. Take a look at the layout and suggest any improvements if you can and also be sure to point out the faults.
Sorry for my bad English  ;)

9
Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD
« Last post by Martin72 on Today at 11:11:16 pm »
Thanks for the info! :-+
But like I said, on eleshop.de you won´t see any siglent scope..
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General Technical Chat / Re: Good soldering flux?
« Last post by Smokey on Today at 11:10:31 pm »
Time to repeat the experiment. Here goes.
16 days later. Hi-res photos are attached.
...

...But you left off my favorite flux, TF5000, so I'm going to have to ask you to do that over...  hah!

Epic experiment!  Thanks for doing that.  If you post csv file, or contents here it's trivial to paste that back into any spreadsheet. 

About the flux attacking bare copper... how big of an issue is that really?  I'm only ever using flux over board area that is either soldered or has soldermask. 
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