Part Sourcing Assistance/Advice Thread

[GeorgeP]

^ any recommendations on a good crimper?

[gepardcv]

I found this one, official Molex but much cheaper than the $300 specialty "premium grade" tool.

Still worried about the 250V rating, though.

[UFN]

If you want something universal then I can recommend the ones from http://www.engineer.jp/index_e.html

Universal for small JST/Molex connectors with 2.0mm/0.1"/0.15" pitch: http://www.engineer.jp/en/products/pa21e.html

Larger model for FAST-On style connectors (cable shoes I think they are called?) etc: http://www.engineer.jp/en/products/pa01_04e.html (the PA-01 model)

Should be available on eBay etc. (unless you know anyone going to Japan where the prices are much lower ). 

//UFN

[Kerry]

Does anyone have a bare board for the original group buy digital attenuator.  I've got parts for another, but no board (not good planning).

I wanted to build it so I can test the controller software for balanced operation.

[luvdunhill]

I have some, but I am not sure how accessible they are. I am on vacation in FL, when would you need them by?

[Kerry]

No rush. I just need one, so let me know when you get back.

Thanks

Edited April 30, 2016 by Kerry

[Craig Sawyers]

On 4/29/2016 at 1:50 AM, spritzer said:

These are sad days indeed.  We should all be using opamps for everything... 

I'm sure somebody will make high performance parts for us but they won't be as cheap as the K389/J109 were back in the day. 

Apart from the 2SK170/LSK170 the lowest noise n-channel FET I've found is the BF862 with 0.8nV/rootHz.  This is a 700MHz surface mount device and is made in the bucket load, and is a factor of several cheaper than the LSK170.  The key it seems is to chose RF devices in which noise sources with low impedance drive (like an antenna) are important.  Difficulty of course is finding complementary devices - the closest are the current offerings from Linear Systems.  At least they do the LSK389 - if they eventually produce the LSK109 (they took long enough to crack the LSJ74 fab problem!) that would be nice indeed.

[kevin gilmore]

i think i have a bare board, will look later

[Kerry]

Thanks

[mwl168]

Has anyone tried using denatured alcohol to clean the flux residual off the PCB? Is it safe for the PCB and solder joints?

Thanks!

 

[muskyhuntr]

I have used denatured alcohol on my boards for years, as have others, and have never had a problem.  I use the highest % I can find.  Note that it will take multiple washings and scrubbings with a tooth brush to  clean the board. Also, it helps to wipe off the board with a paper towel between washings, other wise the resin desolved by the alcohol will remain on the board.

Me

[nopants]

yeah in my limited experience it's come down to the elbow grease and proper rinsing. took me days to properly clean the t2 boards

[mwl168]

Thanks for the information.

I usually use a metal pick to remove the hardened flux residue followed by scrubbing with 90% isopropyl alcohol but it always leaves a residue. I am guessing it's the additive in the alcohol I use. I'll give this denatured alcohol a try. 

[gepardcv]

I use this: http://www.amazon.com/MG-Chemicals-Isopropyl-Alcohol-Cleaner/dp/B004SPJP5O

Still takes several cycles to get a PCB clean enough. Not looking forward to doing this with T2 boards.

[PICaudio]

I prefer a mixture of Isopropyl Alcohol and Acetone (60/40), IMHO I think this mixture clean more easily that if you use Isopropyl only

[oogabooga]

I found 100% isopropanol to work well, and wiping it off while still wet like muskyhuntr says helped eliminate residues.

[JoaMat]

Anyone tried dishwasher?

[mwl168]

16 hours ago, JoaMat said:

Anyone tried dishwasher?

Actually, I read on DIYAUDIO someone did use dishwasher to clean PCB and said it works well. IIRC, it says to use the gentle cycle 

[JoaMat]

Once I cleaned a straight six BMW cylinder head in dishwasher. Very handy.

[Craig Sawyers]

3 hours ago, JoaMat said:

Once I cleaned a straight six BMW cylinder head in dishwasher. Very handy.

And what did your partner say about that then 

[wink]

He was ahead of his time.....

[JoaMat]

On ‎2016‎-‎05‎-‎05 at 1:19 PM, Craig Sawyers said:

And what did your partner say about that then 

Don’t remember the exact words, but she is a very adorable partner.

Got this as a present recently………

[UFN]

Well, she definitely has excellent taste  If she's also tolerant of vast quantities of diy audio parts and gear then she's probably a keeper 

 

//UFN

[luvdunhill]

I just bought now OOP p-ch surface mount JFETs - that seems a bit crazy.

[luvdunhill]

Can anyone recommend a good surface mount, dual polarity, >50V, high hfe, in a power package that can do > 0.5W per package?

I am looking at the PBSS4160PANPS but want more gain, if I can.