Electrical Engineering V3 - Developers

[QUOTE=pentium;47895995]It IS magic. It's helped me in situations where pin density made it impossible to otherwise prevent bridging. [B]The only downside is that it's generally a bitch to clean off.[/B][/QUOTE] Isn't that where rubbing alcohol and a soft toothbrush is godsend?

Plain old rosin R/RMA flux can be left on without problem since it only becomes 'active' at high temperatures, you can leave it even if it does look a bit nasty, it's non-conductive unless you burn it. Other no-clean fluxes can be left as well without problem. For small jobs warm IPA and a small brush work great for cleaning, if you're doing a lot of boards a commercial flux remover that you can wash the board in is the best option, for water soluble fluxes you can just wash the board with water, although in certain cases with moisture sensitive components using a solvent is preferable. Personally I just stick to a pure rosin + IPA mix for soldering since unless you are dealing with very oxidized stuff you don't need a more active flux.

The cheap Chinese shit I have, ends up a sticky mess without cleaning.

Most rosin based fluxes are rather sticky. [img]http://i.imgur.com/ZKLDfIr.png[/img] I usually have to end up washing my soldering iron with IPA as it gets all over the handle when I'm using it.

Rosin in itself is a sticky mess, there's a reason handball players smear it on their fingers, and that's so they don't accidentally drop the ball.

So the [URL=http://www.arrl.org/field-day]ARRL Field Day contest[/URL] is coming up, I'm moving all my gear to my parent's for the day because I can get a big (20 meter long inverted V) antenna up in their yard compared to my apartment. Let's see how the HOA likes a 16ft painter's pole strapped to a deck :v:

[QUOTE=Cakebatyr;47915670]So the [URL=http://www.arrl.org/field-day]ARRL Field Day contest[/URL] is coming up, I'm moving all my gear to my parent's for the day because I can get a big (20 meter long inverted V) antenna up in their yard compared to my apartment. Let's see how the HOA likes a 16ft painter's pole strapped to a deck :v:[/QUOTE] HOAs can honestly eat dicks. So long as you're keeping the yard adequately trimmed and the paint is well-maintained they shouldn't have any business telling you what you can/can't do. My boss almost got in a fight with them because he bought a shit-ton of Christmas lights and the HOA he was living under said "No no no! Only white LED Christmas lights in THIS neighborhood!"

[QUOTE=Cakebatyr;47915670]So the [URL=http://www.arrl.org/field-day]ARRL Field Day contest[/URL] is coming up, I'm moving all my gear to my parent's for the day because I can get a big (20 meter long inverted V) antenna up in their yard compared to my apartment. Let's see how the HOA likes a 16ft painter's pole strapped to a deck :v:[/QUOTE] I may try to get onboard with that, my local hamfest is this saturday so maybe something good can come from it.

[QUOTE=Zero-Point;47916200]HOAs can honestly eat dicks. So long as you're keeping the yard adequately trimmed and the paint is well-maintained they shouldn't have any business telling you what you can/can't do. My boss almost got in a fight with them because he bought a shit-ton of Christmas lights and the HOA he was living under said "No no no! Only white LED Christmas lights in THIS neighborhood!"[/QUOTE] Normally exterior painting is handled by the HOA too :v: So its their fault if they are angry that it isn't done.

Sup guys. I wanna build a AM or FM (whichever is easier/more suitable) radio transmitter and a receiver that work within the 40.66 - 40.79 MHz range. I only need the radio to transmit an analog value such as the position of a pot, and I was planning to use an arduino on the receiver side to read the signal. Problem is I can't find any crystal oscillators within that range. I found 2 crystals (40.695 and 40.685) on ebay that come in transmitter/receiver crystal pairs and use single conversion. Every radio tutorial on the internet seems to use an oscillator with 4 pins. Those crystals on ebay only have 2 pins and I've read that its extremely difficult to make any high power transmitter with them. My transmitter has to be 500mW. Is it doable or should I just give up? It can't be too complex or the components will cost a shit ton

[QUOTE=Catse;47921457]Sup guys. I wanna build a AM or FM (whichever is easier/more suitable) radio transmitter and a receiver that work within the 40.66 - 40.79 MHz range. I only need the radio to transmit an analog value such as the position of a pot, and I was planning to use an arduino on the receiver side to read the signal. Problem is I can't find any crystal oscillators within that range. I found 2 crystals (40.695 and 40.685) on ebay that come in transmitter/receiver crystal pairs and use single conversion. Every radio tutorial on the internet seems to use an oscillator with 4 pins. Those crystals on ebay only have 2 pins and I've read that its extremely difficult to make any high power transmitter with them. My transmitter has to be 500mW. Is it doable or should I just give up? It can't be too complex or the components will cost a shit ton[/QUOTE] I'd recommend reading up on [URL=http://en.m.wikipedia.org/wiki/Intermediate_frequency]IF staging[/URL], [URL=http://en.m.wikipedia.org/wiki/Frequency_multiplier]frequency multiplying[/URL], and [URL=http://en.m.wikipedia.org/wiki/Frequency_mixer]frequencymixing[/URL]. Then look at the block diagram of a AM transmitter and receiver: [T]http://www.g4prs.org.uk/Foundation%20Course%20Material/Transmitter_Block_Diagram_files/image002.jpg[/t] [T]http://www.hobbyprojects.com/block_diagrams/images/amrecev.gif[/t] Also 500mW is easily accomplished with those two lead crystals, in fact you can buy [URL=http://www.qrpme.com/?p=product&id=RM15]Morse code (CW) kits with 500mW output[/URL]. Admittedly PCB design needs to be better the higher frequency you go, and you should definitely take all measures to avoid spurious signals, because they will happen. I'm using AM as an example, but AM and FM are both pretty easy to implement. FM will get you a narrower bandwidth which is [b]always[/b] a good idea. Since you are just streaming data you will probably want to put a modem in there and use individual audio-stage frequencies as bits of data. But for that to work properly you are going to need a stable oscillator. Also at 40MHz you're going to need a reasonably large antenna (wavelength of 7.5 meters) to get that signal out. There's a reason a lot of this stuff is done at 433MHz, a 70cm antenna is tiny.

I first soldered around 2007 and I burnt myself for the first time today. Surprised it took so long!

I burnt myself the minute I plugged in my first iron because I wanted to see if it was hot yet. :v:

[QUOTE=pentium;47895995]It IS magic. [/QUOTE] only when you inhale baby

So I nearly flicked hot solder into my eye...kinda tempted to wear safety glasses now.

[QUOTE=Leestons;47963534]So I nearly flicked hot solder into my eye...kinda tempted to wear safety glasses now.[/QUOTE] Theres a reason why all my sunglasses are UVEX brand :v: But yeah, I did that yesterday.

I have glasses, and I feel pretty safe.

[QUOTE=Leestons;47963534]So I nearly flicked hot solder into my eye...kinda tempted to wear safety glasses now.[/QUOTE] People may comment on me wearing safety glasses when I'm soldering, but I do it because of this very reason. Had a few close encounters, better be safe than sorry.

"Alright, looks like I'm gonna have to get a DB-25 extension so I can properly connect this CNC breakout board..." '[url=http://www.amazon.com/gp/product/B001UNLKOG?psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00]Yes, this looks like it'll do the trick...[/url]" "Okay, double-check before ordering, yes, DB-25, that's correct. And, done!" And then I get it in the mail and it's fuckin' DB-35. :/

So I've got an idea to control the lighting in my apartment using an Arduino and a TFT touchscreen display shield. My question is, do shield take up all the pins on the arduino?

[QUOTE=proboardslol;47978749]So I've got an idea to control the lighting in my apartment using an Arduino and a TFT touchscreen display shield. My question is, do shield take up all the pins on the arduino?[/QUOTE] Depends on the shield, usually they only take a few and the rest are passthrough

[img]http://i.imgur.com/sfVPgW1.png[/img] this is the underside of the shield. looks like it's used.

[QUOTE=papkee;47924443]I burnt myself the minute I plugged in my first iron because I wanted to see if it was hot yet. :v:[/QUOTE] dumb use of human temperature sensor :v:. I usually just tap on tip very fast - 0.1 second touch - generally I sense hotness in my finger one second later - no damage done.

Or we could all do a more sensible thing and rub it on the wet sponge to see if it sizzles.

I stopped using sponges once I discovered the magic of the brass sponge.

I use both, brass to clean off the majority and the sponge to actually get rid of the oxide layer.

I look at the temperature readout on my station.

I slap it on my tongue and see if it burns.

[QUOTE=ddrl46;47982269]I use both, brass to clean off the majority and the sponge to actually get rid of the oxide layer.[/QUOTE] The problem with my iron is wherever I clean it on the sponge the solder just balls up at the point. Probably because of the tips shape.

Nikomo I added you on steam. I gotta ask you a few more questions. Top of the page Uh..shit. I got nothing. Too busy debugging that teletype. Have an analog nightmare. [img]http://www.amplifier.cd/set/diode-bridge-part-five/images/20080629_02.jpg[/img] [editline]asda[/editline] [quote]Mips: he's an analog engineer Ddrl46: no he's mad [/quote]