What's this please? (Component Advice)

[VinzC]

This thread is slow and I got a new cheap microscope, so...

Found a few of these on the dollar cart and had no idea what they were, although the first picture makes me think they might be antennas.

(Those are millimeters)

Anybody know?

That pattern on the surface curiously looks like Hilbert's curve, a fractal pattern, *very* interesting.

[timelessbeing]

They can be 3D too.

[VinzC]

Thanks timelessbeing. On the other hand I'm wondering... Wouldn't those closely coupled branches counter each other in a so-tight 3D assembly? I'm curious how [efficiently] the energy is radiated from those structures. I'm expecting the efficiency of such an antenna to be from slightly to tremendously reduced due to part of the radiated energy cancelling out the radiation from other loops in the assembly — e.g. the more concentrated the Hilbert loops, the more losses... if I'm making sense. Can anyone shed some light on this?

EDIT: There is indeed a paper on the topic but I need some assistance putting it all together  .

[timelessbeing]

https://pdfs.semanticscholar.org/11d1/9668fe46e2ac7a8c0a33f80ce5b6a4683aec.pdf

[VinzC]

https://pdfs.semanticscholar.org/11d1/9668fe46e2ac7a8c0a33f80ce5b6a4683aec.pdf

Well, thanks but that's not really answering my question. I was paying attention to the fact that in this kind of structure you have alternating clockwise and counter-clockwise "loops". I'm definitely no expert in antenna theory but I'd intuitively expect such an alternating pattern to be less efficient in radiating than a single loop for instance. I stand to be corrected if I'm wrong... which is exactly what I asked for, if you see what I mean. So can anybody explain, in layman terms if my deduction is correct or what I've missed otherwise?

[scuzzyTerminator]

Well, thanks but that's not really answering my question. I was paying attention to the fact that in this kind of structure you have alternating clockwise and counter-clockwise "loops". I'm definitely no expert in antenna theory but I'd intuitively expect such an alternating pattern to be less efficient in radiating than a single loop for instance. I stand to be corrected if I'm wrong... which is exactly what I asked for, if you see what I mean. So can anybody explain, in layman terms if my deduction is correct or what I've missed otherwise?

I don't know much and I'm trying to grasp this. The paper (and the supplied figure) seems to say that only the tiny vertcal monopole is the radiating antenna while the fractal part is the antenna's resonating load.

So I think you're correct that the squiggles' radiation cancel out but they also induct to create a reactive impedance providing resonance.

It's still pretty opaque to me.

Thanks Timelessbeing. You've made this very interesting.

[VinzC]

Thanks scuzzyTerminator.

That's probably something to ask Shahriar from the Signal Path Youtube channel .

[timelessbeing]

Crack it open and lets see what's inside! Use whatever you've got ... chisel, knife, snips ... percussive maintenance.

[kjr18]

Hi everyone, I kind of want to know what this chip is. As far as I know it's led driver, it's from cheap led vehicle mounted (12-24v) working spot light. It has this annoying quirk that I can get maximum light output at exactly 12.5V. Anything less equals less light output, anything more means less light output. Chip marking are 70DD and 1718 and package is soic8. If you want I can provide photos or schematic that I managed to make.

[PointyOintment]

Crack it open and lets see what's inside! Use whatever you've got ... chisel, knife, snips ... percussive maintenance.

More advanced PCB deconstruction techniques: https://www.google.com/search?q=joe+grand+pcb+reverse+engineering

[Sousuke]

I just picked up a load of chips and stuff like that, Some I can find out what they do on parts.io but no idea on how to offload them as I have no use for them.

Like a 2KG Bag of PIC12C508P-04 Micro Controllers 
20 Zilog Z8430ADS 

and so much more I have no idea WTF to do with them!

[amyk]

I think the 150RG are 150 ohm resistor networks. The others can be found easily on Google.

The 8085s are probably worth quite a bit...

[timelessbeing]

Glue them dead bug style to a piece of wood and use it as a boot scraper.

[VinzC]

Wow! That's a nice vintage pack that you have there!

Glue them dead bug style to a piece of wood and use it as a boot scraper.

 

______

12C508: PIC microcontroller

Status: Not Recommended for new designs

(no shit Sherlock? :-D)
27C2001: 1Mbit as 128K x 8bits EPROM (UV erasable)
A bunch of Z80A microprocessors
8259: Interrupt Controller for (old) Intel architectures, like PC-AT
µA324: long before it was called LM324
MCM6810: 128 x 8-bit RAM
MCM60L64: 8K x 8-bit SRAM
6850: Serial interface (RS232)
RS 140-013: maybe a quad op-amp, 14pins (resistor array seems unlikely in packs of 7)

Not that I'd be a buyer but do you plan on selling those? I admire the whole bag of Microchip PIC's .

EDIT: On a second thought, maybe Fran Blanche would be interested in getting some as she has very nice & didactic tutorials on vintage technology. Maybe you can just ask her if you wonder what to do. Just suggesting.

[gamalot]

14-pin resistor network is very common

[salbayeng]

The resistor array just has a RS house number on it
https://au.rs-online.com/web/p/resistor-networks/0140013/

[amyk]

The resistor array just has a RS house number on it
https://au.rs-online.com/web/p/resistor-networks/0140013/

Good find. Date code appears to be 1978. RS has apparently been around since 1937.

[salbayeng]

Yep, Radiospares / RS has been around a while , there was some recent marketing ploy a year or so ago celebrating some anniversary.

House numbers can be annoying especially when trying to manage BoM's ,
You get them popping up all over, e.g. the NTExxxx range of overpriced equivalents , Element14/newark/farnell with the MCxxxxx range, HP equipment usually have normal components but marked with xxxx-xxxx partnumbers, General Electric use diodes on their 40yr old PCB's labelled "A14P" that is just a 1n5061.  Components intended for military or aircraft use will sometimes have cage codes or JAN numbers.

[VinzC]

The resistor array just has a RS house number on it
https://au.rs-online.com/web/p/resistor-networks/0140013/

Indeed, my bad (d'oh!)

[LukeW]

I'd like to find a manufacturer and MPN for a tactile switch that looks like the following.

It's a SPST momentary button, measures about 4mm x 3mm x 2mm, has only two SMD pads, and it has no "pillars" that go into PCB holes underneath.

[VinzC]

I'd like to find a manufacturer and MPN for a tactile switch that looks like the following.

It's a SPST momentary button, measures about 4mm x 3mm x 2mm, has only two SMD pads, and it has no "pillars" that go into PCB holes underneath.

https://duckduckgo.com/?q=tactile+switch+micro+smd&ia=images

[salbayeng]

[edit]
Ok , I've bought a similar switch before  ,The C&K PTS820 https://au.mouser.com/datasheet/2/60/pts820-1382642.pdf
some of the variants have pegs , some do not , I have one without pegs, PTS820J25KSMTR , it has  a blue button https://au.mouser.com/ProductDetail/CK/PTS820J25KSMTRLFS?qs=%2fha2pyFaduiw33jyUWT7Ti864j3IB0%2fRHgV%252baQPTgLqT2jafLvvInQ%3d%3d

CAUTION , many of these SMD switches (the PTS820 included) have parts of the metal case going to PCB level, so if you use wide pads , you will short to the metal case. (Discovered this the hard way!)

[edit] ---- not this one---  the KMR6 has no mounting pillars, but the button isn't round  https://au.mouser.com/datasheet/2/60/kmr6-947828.pdf  (looks like a 4 pad PLCC4 pad arrangement though)

CAUTION , many of these SMD switches have parts of the metal case going to PCB level, so if you use wide pads , you will short to the metal case. (Discovered this the hard way!)

[Yansi]

Hi!
Can you please identify this little RF LNA transistor? I know it is some pretty common type from back then, I even knew the part number but forgot it. Cannot find it anymore.

It is a small four legged ceramic package marked "101", same size as a typical RF MMIC amplifier like ERA-5.

Thanks a lot

[Yansi]

After some more intensive digging, I think it may be ATF-10136. Is it possible? The datasheet does not state the package marking.

https://www.qsl.net/n9zia/trans/ATF10136.pdf

[amyk]

https://www.aliexpress.com/item/Free-shipping-10pcs-lot-ATF-10136-screen-signal-amplifier-101-cross-0-5-12GHZ-new-original/32800024346.html
https://www.aliexpress.com/item/10PCS-3296W-50K-Ohm-Trimpot-Trimmer-Potentiometer-3296W-503/32814408008.html
https://www.ebay.com/itm/NEW-ATF-10136-0-5-12GHz-Agilent-Low-Noise-GaAs-FET-x3pcs-NF-0-5dB-RF-LN-Amp-/310383898607
http://www.912688.com/supply/297520572.html

Enough proof?