So long 2N5089, J310 ... and 2N3904!?

[amptramp]

I guess we had better go back to tubes.  No surface mount equivalent for those!

Ummm, well, actually, there is. Or could be, anyway.  

Check up on Field Emission Triodes.  If you want to take the trouble to pull a permanent vacuum over the top of a silicon surface, you can nan-etch pits with atomically sharp "teeth" arrays at the bottom. Put one conductive circle around the pit, and another around that. A few tens of volts between the toothed array and the outer circle boils electrons off the sharp points from sheer field strength emission overcoming the surface work function. If the tooth array is negative wrt the outer circle, electrons boil off and loop up and over to the outer-circle "plate". The inner circle grid can cut this down or off.

Sounds like a lot of work for not much benefit, right? It turns out it's massively radiation hard, which diffused junctions are not.

I first saw this in the 70s, filed it away. I just googled and the research is now all about carbon nanotube FETriodes. They're still there.

So yes, you could do an SMD tube. Just gotta etch carefully enough.

We once investigated a display manufacturer in Texas who used carbon cathodes laser-ablated from a diamond in displays.  The cathodes took the form of carbon cones that were field emitters.  Wherever the cones landed was a cathode segment and there may be hundreds of them in a single pixel.  They were vacuum fluorescent using a zinc oxide anode, so they ran at 60 volts and were the normal pale blue colour of vacuum fluorescent displays.  These displays were not bright enough for our use (cockpit displays), but they were good enough for the normal uses of vacuum fluorescent displays such as clocks and radio displays.  Maybe the normal thermionic displays can be used as a field of triodes the way some people use tuning eye tubes as triodes (with a µ of 15).  In fact, I have a German Loewe-Opta battery tube portable AM-FM radio that uses the tuning eye as the paraphase inverter for the push-pull output stage.  Just think of all the vacuum fluorescent displays with grids taking in row information and anodes for the columns.  Lots of triodes operating with a common directly-heated cathode and you can get the bonus of light output.

[digi2t]

So few years down the road, boutique builders will charge 400$ for pedals that have 2n3904 for that true vintage tone.

Yes... so start hoarding. Now. 

I have a decent stash of 2N5088/9's at the moment. $10000 gets the lot.

Any takers.....

Anyone?

Bueller......

[Galego]

SMD trannies aren't that small or difficult to use even with home-etched pcbs. And you save space on your designs.

[thehallofshields]

Someone should get started designing a Surface-Mount to Through-Hole adapter.

[Luke51411]

It's already been done for some parts. I've done some smd JFETS on the adapter boards.

[alanp]

I find SMD a wee bit easier if I have half a beer in me. Without that, my hands start to shake due to nervousness coupled with trying to focus my precise hand movements, and with more, coordination goes down the toilet entirely.

[pickdropper]

As for now, Fairchild 2n3904s are still available.  The clock is ticking, however.

[bloxstompboxes]

I work with 1/16th Watt resistors and other smd components at work but I have a microscope that helps tremendously. I guess i'll have to get a used one or something off ebay for home in 20 years or something. lol.

[jubal81]

Semiconductors are one thing - having to hand-solder 40-50 SMD resistors & caps? Noooo thanks.

[smallbearelec]

There, there. It'll be all right. I have this stash of 5089's that I got directly off the test machines back at National Semiconductor. I'm aging them right now, because they sound best if they're aged for 19.34 years before ever being soldered on. They'll be ripe in about a year. I'll send you an email then. I'm pretty sure they'll be affordable fairly priced.

I can't wait until the day we are hearing about how the inconsistencies in the TO-92 manufacturing process is what makes them sound so much better than smaller alternatives...

When DIP ICs go away, do ya think I'll be able to make a killing selling "Cave-Aged" chips?  

[R.G.]

Semiconductors are one thing - having to hand-solder 40-50 SMD resistors & caps? Noooo thanks.

Not too bad. What it really good is placing them on solder-paste coated pads, then sticking them into a toaster oven to reflow.

Soldering 40-50 SMD resistors and caps SIMULTANEOUSLY - priceless.   

[Hatredman]

Hummm, maybe I'll be needing to redesign the Burst Box tu use SMDs. Hopefully the Big Copper Thing will still be big enough.

[Mac Walker]

Not just through-hole components......eventually silicon will be phased out entirely as well:

http://www.eeweb.com/blog/sachin_seth/gan-transistors-poised-for-revolution

[amptramp]

There are a number of companies that have bought up old semiconductor foundries and are making obsolete parts in order to maintain military aircraft and radar systems.  Maybe they could be a new source of old transistors in TO-18 and TO-39 cases.  I remember one of these companies giving a talk at our place and the salesman's name was "Rusty Key".  Sounds like the right man for the job.

[digi2t]

Someone should get started designing a Surface-Mount to Through-Hole adapter.

Like this?

[jimbeaux]

Ran across this +40 year old article - Times / Technologies change - but worries don't

ElectroNotes - Issue #17 (6)  - January 30, 1973- Bernie Hutchins

7b. SURPLUS WATCH: Is the Surplus Market Drying Up
There has been some talk recently to the effect that the surplus market is about played out, and that prices will be starting back up soon, and that some items will become unavailable. B&F has suggested this in a recent flier. In the last year, we have seen the 741 opamp go from about $1.45 to 39¢ or less, and TTL prices have halved in most cases. On the other hand, RTL is very rare and ex:pensive now. I have heard that it has become difficult to obtain IC's from many of the OEM suppliers, which would perhaps indicate that less will be spilling over into surplus. I'm not going to try to answer the question in the title, perhaps someone else would like to. Two observations can be made. (1) We have seen a fantastic drop in prices, and perhaps an over-shoot, and a few items have started back up, but only individual items of a series, and only from certain of the dealers. If you need any of these items, it might be a good idea to grab some. (2) As mentioned above, RTL has become scarce, but you probably don't care, since TTL is better and cheaper you say. There are a lot of very new IC's being designed and produced, and if an electronic boom does dry up the surplus market as it is currently run, there may be overruns and seconds on these to be had, and you may be saying in another year "Who wants TTL, MOS is better and cheaper". If I had to give advice, I would say that if you have projects planned and need parts, don't wait much longer to get them, but it might not be worth it to stock up on parts for which you have only an idea that you might need in a year or so.

[PRR]

That article runs every year in the trade magazines.

The specifics change, but it is a good reliable story which needs only minor re-write each time you run it.

There is another "surplus boom" article you run 5-7 months later.

The articles sometimes run out of sync with reality, but that does not matter, because whatever you say WILL be true sooner rather than later, and it's really about exciting headlines to get readers to buy/subscribe.

In and before 1973 there was a big boom in military and industrial electronics. Lots of new toys for the Generals to buy for their fleet, and lots of process-controllers so your steel or styrene or oil got cooked consistently. A side-effect of any such boom is vast piles of over-runs and marginal-rejects, which got dumped on consumer and experimenter markets. Sometimes a dollar a pound.

I remember BIG boxes of large mystery boards smothered in excellent transistors and caps, fallout from NASA and Viet-Nam electronics. Jameco flourished on loose-parts excess inventory.

Of course every boom has a bust. The Generals run out of places to put new toys. Factories discover that process-control invents new problems they never had before. It takes time to digest. New orders dry-up, semi-fabs go on lay-off, surplus trickles out of the system.

Anybody who bought PC RAM in the 80s and 90s knows how prices spike/plunge. 16K RAM price might be steady for a few months, and then the 64K RAM comes out at high price. Not to mention when a factory burns or a ship sinks, and everybody is bidding on a small supply. But for some buyers, 4X RAM at 8X price is still a deal, so 16K prices slump, then plummet as 64K prices come down. You can't give-away 16K RAM. And then a few years later when everybody has thrown-out all their 16K, but a few users need to maintain 16K-only machines, 16K prices go sky-high.

The through-hole problem is a little like the 1973 RTL issue. NOBODY buys millions of RTLs or TO92s any more. The factory won't run-off "just a few", they are chasing the million-selling TTL CMOS, or SMD sales. Line start-up is very expensive and they need to run a lot of parts to cover that cost.

For own-use builds, the "dry up" of through-hole parts is not an urgent problem. When supplies are "low" on a part that used to sell many millions, that means many thousands are still in the bottom of bins. When main-line distributors want to clear that bin for a better-selling new product, they know to call Jameco or Rochester or our pal Small Bear, and get some quick small-change and instant bin-space. There is a hierarchy of big guys, small guys, and 1-room guys who handle parts that have gone "obsolete". Today some of that is Chinese traders who shovel junk to market, but there are still good guys who know your passion and keep a reasonable stock of the good stuff in inventory.

[stevie1556]

I'm glad I'm getting used to SMD already, to the point where I'm trying to change my whole pedal board into SMD builds.

Semiconductors are one thing - having to hand-solder 40-50 SMD resistors & caps? Noooo thanks.

Doing that is so much quicker and easier then TH components. Use a solder paste, place a component in roughly the right place, heat the solder and when it's molten it pulls the component into the right place. Use a hot air soldering station though, quick easy, painless.

I use one of these cheap Chinese ones: