EMRFD Message Archive 10540

Message Date From Subject
10540 2014-12-05 19:17:46 David Snowdon On-Semi ending TO-92 production (Was: TO-92 J310 FETS Now Obsolete)
This was my messaged posted last week on the QRP-L list:


Subject: On-Semi ending TO-92 production

Some transistors affected:
PN2222, 2N3904, 2N4401, 2N5401, 2N5500, 2N5501, 2N5551, 2N7000

Also included are these family of parts: MCR, MPSA, MPSH, MPSW,

There are other sources, but these are some classic well
understood devices.

Fairchild so far continues making most and there are new
players in the field, with names such as Central Semi,
Advanced Semi, Comchip, Diodes Incorporated, etc.

Full listing:
http://www.onsemi.com/pub/docs/pcn/PD20685.pdf

My eyes aren't getting any better, but it looks like the writing
is on the wall regarding learning SMD prototyping and construction
techniques.

David
VA3DKS


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10541 2014-12-05 20:57:11 Ronan McAllister Re: On-Semi ending TO-92 production (Was: TO-92 J310 FETS Now Obsole

>My eyes aren't getting any better, but it looks like the writing
>is on the wall regarding learning SMD prototyping and construction
>techniques.
>
>David
>VA3DKS

Although the expense, "tooling" and learning curve to move into surface mount components is daunting, I keep thinking we humans are masters at adaptation.  It can be done I tell myself even though I am a little unsteady with little parts.   You can get hot plates on eBay for $100 or less, or even convert a toaster oven to a SMD solder reflow tool as I am reading.  

Quite a few tips/tricks on youtube and elsewhere.   3D stereo microscopes even those with color camera sensors and articulation are the key to seeing small things and are nearer my budget than ever (scroll through these for example some 200-300$)

I'll probably not venture into any of this without watching someone experienced do it and a lot more research.  Maybe I'm just too old!!!  A significant number of "benefits" including shorter leads mean less input "antennas" as regeneration resources, faster path to a ground plane, and the components are going down in price in opposite of through-hole which will only become more difficult to find and costly.  

The above is what I am trying to convince myself I can do.  If I succeed or fail miserably, that's another story!

Ronan/KB6NHQ


On Fri, Dec 5, 2014 at 5:52 PM, David Snowd
10542 2014-12-05 22:48:07 Gene W5DOR Re: On-Semi ending TO-92 production (Was: TO-92 J310 FETS Now Obsole

SMD resistors and capacitors aren't so bad if you use the 1206 size.  The problem comes with discrete transistors and ICS.   I bought some 6x power glasses online (couldn't find any that powerful in stores) and using them is almost as good as using my stereo 3D microscope.

 

Gene, W5DOR

 

10543 2014-12-06 01:11:41 farhanbox@gmail.c... Re: On-Semi ending TO-92 production (Was: TO-92 J310 FETS Now Obsole

there are other problems with smt. the capacitors are unmarked. you have to cut a board, ugly doesnt work. but they look neat!

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