what parts would you stockpile because they may extinct? - Page 1
Forum section: electronics / beginners

author: exe
author_rank: Unknown
timestamp: April 13, 2020, 08:20:48 pm
content: Hi there,My hamster instinct kicks in and tells me to buy some parts just in case. I wonder what would you folks pile up?My short-list:1) jfets. I use them as current source. They are also depletion-mode, sometimes this is handy... if one can live with their parameter spread.2) depletion mosfets. I'm yet to buy one, but looks interesting to play with.3) maaay be ceramic-packages voltage reference, such as those from Maxim (I know they make parts obsolete very quickly and unpredictably, but if it's a good part then I don't mind buy a few for future prototypes)3) lateral mosfets... or, wait, it's too late already. I think I have to order from the only manufacturer left. Or may be just give up on them, the only application I can think of is audio, but there is no shortage of power bjts, so, not sure about this one. Their performance is not stellar, I tried to build a power supply using a lateral mosfet, but its rds(on) of 1ohm and gate voltage of ~10V made it impractical....So, what do you think would be worth buying until they are gone? Any interesting analog devices, like opamps, voltage references, comparators, discrete devices, etc?

author: Yansi
author_rank: Super Contributor
timestamp: April 13, 2020, 08:28:50 pm
content: Hoarder whatever you want to (and will) play with. Making generic hoarder lists does not help much. Every EE is quite picky abotu the stuff he uses and can have pretty different requirement on his component stockpile.

author: bsfeechannel
author_rank: Super Contributor
timestamp: April 13, 2020, 08:42:57 pm
content: I'll miss jfets. I already have a small stock of them. They're still being used in some niche applications, such as vintage guitar effects pedals.

author: exe
author_rank: Unknown
timestamp: April 13, 2020, 09:13:45 pm
content: Quote from: Yansi on April 13, 2020, 08:28:50 pmI'm looking for new toys. It's less about part numbers, it's more about the story why the part made to the list.Quote from: Yansi on April 13, 2020, 08:28:50 pmOh yeah, I'm no exception.

author: Vovk_Z
author_rank: Super Contributor
timestamp: April 13, 2020, 11:36:55 pm
content: It seems to me all semiconductors can extinct. It's not a problem with simple ones (diodes etc) because we usually have new analogs or even upgrades. But some integral devices will definitely extinct.Simple passive devices (resistors, capacitors) usually not a problem because we'll have some analog (for example NP0 ceramics instead of some film types).

author: OwO
author_rank: Super Contributor
timestamp: April 14, 2020, 03:53:51 am
content: 3) LDMOS transistors are still very much common place and you can get refurbished 50W rated ones for $5 or so (less than $1 from taobao). For example search MRF9060M, M9060M, MRF5S9070NR1, M59070N on aliexpress/taobao.

author: james_s
author_rank: Super Contributor
timestamp: April 14, 2020, 04:12:03 am
content: Are they genuine though? There are a LOT of fake/re-marked parts out there, I'd be very hesitant to buy any kind of exotic hard to find parts from random China sellers. Some parts like the Dallas NVRAM and RTC modules are all fakes.

author: OwO
author_rank: Super Contributor
timestamp: April 14, 2020, 06:08:25 am
content: The part numbers I mentioned above are usually fine, there is no lower end variant that they can relabel, but some of the MRF184 for example I suspect are relabeled MRF182 instead. Here the MRF5S9070N costs $0.5 and I've tested a few close to full power. They are all refurbished (salvaged from base stations) though, and new ones are impossible to find.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: April 14, 2020, 07:33:01 am
content: When building stuff, I usually purchase a bit more of the important items (ICs, low noise trannies/fets and alike - no electrolytics of course). Thus my stockpile increases by and by. Moreover, this puts me in a position to completely repair my stuff even many decades later.

author: Yansi
author_rank: Super Contributor
timestamp: April 14, 2020, 09:31:21 am
content: Quote from: exe on April 13, 2020, 09:13:45 pmThen if you're looking just for what groups of components to stockpile, then I'd recommend this:JFETS. Those linear and low noise ones. Especially complementary pairs!High voltage low or medium power linear transistors, that are FAST. They were common as sand in the days of CRTs as color amplifiers and as outputs in oscilloscopes, but nowdays almost impossible to get. Let alone trying to look for a complementary pair.High power linear transistors, that are fast. It seems that market for linear power transistor is also declining, mostly all you can get is some TIP35/36, slow generic shit. I mean, where have all the fast (ft>10MHz) TO247 and TO220 transistors have gone? These are useful not only in audio amplifiers, but also for any kind of general purpose signal amplification. And the transistors above are good for voltage amplification stages.Linear power mosfets. There is nowdays almost zero available linear mosfets. By linear I mean ones that can be used in the linear region. Lateral mosfets are almost a dead specimen and vertical ones are pain in the ass to use as linear ones. It can be done, although one has to do some research first.

author: Mp3
author_rank: Frequent Contributor
timestamp: April 14, 2020, 11:20:05 am
content: tempco resistors and elna silmic ii capsalready got an OK collection going...