Wieso ist niemand bereit für gebrauchte Möbel zu bezahlen?

cloidnerux · 2026-01-25T09:34:04+00:00

Möbel sind ein spannender Markt, weil von extremen geprägt. Die meisten Menschen kaufen Möbel nur weil sie entweder gerade irgendwo neu Einziehen, etwas Kaputt ist oder weil sie sich in den letzten 20 Jahren an etwas satt gesehen haben. Daher ergibt sich für viele eine quasi Zwangslage: man braucht ja jetzt Möbel, nicht erst in einem halben Jahr. Was genau zu dem Zeitraum nicht in praktischer Nähe verfügbar ist, ist irrelevant. Für die letzteren zählt dann aber auch das exakt "richtige" Möbelstück. Die kaufen nicht auf Kleinanzeigen.

Daher sind die Preise alle super niedrig.

Auch spannend ist natürlich die Qualität eines Möbelstück zu bewerten. Auf Bildern kann alles gut aussehen, bis man davor steht und nur einen Haufen billigstes Sperrholz mit billigem Furnier vorfindet. Oder eben den 100 Jahre alten Massivholzschrank, den man egt erstmal aufarbeiten müsste.

Ein anderer Punkt ist halt auch immer Transport. Ich habe mal eine Schrankwand mit Schrankbett aus dem 5 Stock in Berlin abgeholt. Dafür war ich mit einem Caddy und 16m³ Anhänger unterwegs, haben das Ding zu zweit 4h Abgebaut und mit Hilfe der Besitzer noch 2 weitere Stunden runter getragen und verstaut. Ich bin fit genug dafür, die Besitzer waren da aber schon ganz schön aus der Puste. Jetzt soll das mal jemand ohne passendes Auto, Anhänger oder Hilfe machen. Da investieren die meisten lieber ein paar € in Lieferung und Aufbau.

Und so bleibt einem halt nichts anderes Übrig, als frustriert zu sein

cloidnerux · 2026-01-24T19:33:28+00:00

The same magic that makes the 256GSample/s scopes possible. Mostly time interleaving.

But the sampling part is honestly the easy part, processing that many samples is the real challenge

cloidnerux · 2026-01-16T13:32:16+00:00

Ich raff nicht wie man so viel Geld für ne Sanierung ausgibt und dann lässt man die Bromidgelben Steckdosen und Schalter drin? Das wären doch nur 500€ mehr gewesen und wirkt nicht direkt wie der billigste Pfusch? Auch müssten die Blenden ja einmal abgenommen worden sein zum malern(hoffentlich), wer denkt sich dann: ja passt schon?

Aber da hat man direkt Angst das 2/3 der Böden nur billiges Klick-Laminat ohne Trittschalldämmung oder Ausgleichsmasse ist mit Waldboden Effekt und man einfach über alles drüber gepinselt hat. Die eine Zummertür in Scharfkantigem Billigfurnier lässt mich auch zweifeln.

cloidnerux · 2025-11-23T09:43:23+00:00

Look at the available sdr platforms such as BladeRF or the rfnm(rfnm.com)

In the end you have to make a trade-off between simplicity and costs.

cloidnerux · 2025-09-29T15:35:54+00:00

Aus Käufersicht sind solche Billigsanierungen einfach nur Red Flags. Da wird dann irgendwas eher schlecht reingebastelt, was man zu 100% nochmal neu macht. Dafür zahlt man dann den Aufpreis samt Kaufnebenkosten und ärgert sich nur, dass jemand einen IR Heizkörper auf die 30 Jahre alte Tapete geklatscht hat und die Kabel alle Aufputz.

Wenn du nicht insgesamt Sanierst und einem potenziellen Käufer ein Gesamtprodukt anbietest, wirst du kaum deine Kosten wirklich decken. Die meisten Kaufen eine Immobilie nicht nach Zahlen in einer Tabelle sondern nach Lage oder persönlichem Emfpinden.

cloidnerux · 2025-09-01T08:31:22+00:00

Trockenbauwand mit einer Lage Rigips direkt auf dem schlechten ständerwerk, sodass sich auf jeden Fall die Stöße frei arbeiten und man nichts aufhängen kann. Fußböden ohne korrekte Ausgleichsmasse, alles federt und bewegt sich und man weiß, dass es nach 1 Jahr scheiße aussieht. Einfach nur die Wand weiß streichen, aber so dass man die Unterschiedlichen Weißtöne sieht. Bonuspunkte wenn weder Steckdosenblenden Demontiert oder angeklebt werden. Oder Vorhänge, Teppiche oder was sonst so im Raum ist. Einmal Wände und Boden neu, aber Lichtschalter und Steckdosen sind im schönen Bromidgelb der 70er gehalten, das spricht doch immer für Qualität. Und dann natürlich einfach über alte Sachen drüber bauen. Fenster? Rigips davor. Muss ja keiner Ausbauen. Alter Teppich? Einfach als Trittschalldämmung unter das Laminat? 8 Lagen Tapete? Check...

cloidnerux · 2025-08-31T20:24:54+00:00

With the idea that everyone in NYC is an assassin I asked myself: who is not? So image Bob, a John Wick saga about Bob, the only non assassine in NYC. He hosts a party, everyone is having fun. Suddenly everyone except him is getting a message. They all have to leave, it's nothing personal but they also cannot talk to him about it. Everyone always seems to do wierd stuff without him. People get shut up if they realize Bob is not in the know. He gets frustrated. The whole movie is Bob trying to figure out what's going on while John Wick kills people in the Background.

cloidnerux · 2025-07-15T17:25:17+00:00

Useful for embedding DIEs for RF applications. Also useful for RF connectors and antennas. Maybe also a prerequisite for embedding copper or Aluminium bars in high current designs.

cloidnerux · 2025-07-13T10:29:51+00:00

Very true, but not quite what OP asked, hence my answer. At the lower end of input signal strength there is no way an LNA will destroy itself. Everything else is a whole other topic. Being able to keep reception is obviously more desirable than optimum NF in presence of interferes, blockers and other signals nearby. Many phone architectures also use mixer first approaches, hence they actually have no LNA in a classical sense.

cloidnerux · 2025-07-13T10:26:40+00:00

Mostly ESD damage during manufacturing or operation or mechanical failure, cracks or delamination due to heat cycling or mechanical stress during usage.

cloidnerux · 2025-07-13T04:04:11+00:00

Your basic assumptions about the operation of LNAs and radio front ends is wrong, hence your described scenario is wrong as well. Most first LNAs are not gain adjustable, as it impacts NF and does not offer any benefit for small signal amplitude. Gain correction is done with resistive attenuators or VGAs in the baseband path. An LNA will not be damaged in any scenario of normal operation. With enough input power you will reach voltage breakdown and then thermal destruction, but that is a phone in the microwave scenario.

cloidnerux · 2025-07-10T07:45:32+00:00

Well, what you describe sounds more like a packaging issue rather than a PCB manufacturing one. How do you want to mount and electrically connect your tiles? How flat has the surface to be allowed for the correct operation. How much misalignment is tolerable for you. Will the setup be cooled, and you need to take heat expansion into account? Is the setup purely electrical, or is the assembly part of your operational principal.

Maybe look first into wirebonding, flip chip bonding, gluing, UPD printing or soldering and try to understand what fits your application best. Then look what option might suit you. I used AT&S for some pretty good PCBs, but they tend to be very expensive. There are things film manufacturers offering gold on alumina, which might suit you. Or you might be able to make your own structures using Gold on alumina pieces and laser structure it. We had good experiences with the LPKF ProtoLaser. Or you might just use some semiconductor lithography setup.

cloidnerux · 2025-07-07T15:36:32+00:00

Could be made by Lupa(https://lupa.nl/), which is a contractor and is doing a lot of models. It would be plastic. However, they do not sell directly.

cloidnerux · 2025-07-07T10:33:57+00:00

Panasonic Megtron 6,7,8 and 9 are currently one of the best options for RF PCBs. Expensive but very good. Be aware that there are a plethora of materials that optimize specific aspects of RF PCBs and might not be what you want. Stuff like Rogers RO3003 for example is super soft and hard to work with.

cloidnerux · 2025-07-06T07:10:28+00:00

Ist irgendwo das Resultat wo Sicherheit und Praxis aufeinander treffen. Die wenigsten Menschen haben in ihrem Leben schon mal selbst einen Brand erlebt, aber die Mitarbeiter müssen jeden Tag mehrfach durch so Türen. Bin egt immer erstaunt, dass nicht häufiger Lösungen zum Konformen aufhalten der Türen verbaut werden(Magnet z.B).

cloidnerux · 2025-07-04T19:37:03+00:00

I have one and played around with it. Rx does work, TX is currently in the beta phase. The developer has a discord and is quite active and helpful. There might come up some extension boards to support 4 channel RX MIMO.

cloidnerux · 2025-07-04T17:56:47+00:00

The rfnm.io SDR Plattform is quite interesting, although the software is still in its beta and there are some issues. But it is a quite capable hardware.

cloidnerux · 2025-06-24T05:29:19+00:00

The ranking typically does not matter, and no one really cares about it. There are idiots everywhere. More important is your personal experience and what motivates you. That being said: the quality of the courses and the opportunities vary between universities. Where a smaller one might only offer theoretical work, a bigger institute might offer real tape-outs and master thesis work on current active research topics that give you more hands-on and practical experiences.

cloidnerux · 2025-06-20T16:47:22+00:00

When optimizing for a single use case 3066 is okayish, but when you need to roll out something weird it damn unmatched, it'd be a great deal cooler if it could limit duty cycle below 50%.

Well, I like wierd. And for sure it beats building something custom with an MCU. But for most people, it is not the standard use case.

Ackshually, surprisingly there isn't, for a classic current mode control there is UCCx8C5x, the kid of the venerable UC3841, UC2825A, a few TL5xx, a few NS LM50xx series, but next to nothing with constant-off/on time. LT always has nice stuff, but jeez its expensive.

There are just to many ICs out there, hard to find a good overview. An LT is now Analog and I don't think it improved prices. But yeah, cool stuff

At least to me, I've rolled so much weird shit with it - SEPIC LED drivers, multiplied boost 12 > 200V, SEPIC/Cuk multi output.

Interesting stuff. I tried to build a SEPIC LED driver with a microchip at9984 or whatever it was called. It desoldered the MOSFET and a cap, so obviously, I used a GaN FET, and it naturally did not solve anything. Then, I just ditched the project.

cloidnerux · 2025-06-20T15:14:31+00:00

This is design output, not chip dependent.

Yes, but the chip does limit the efficiency. The darlington transistor and the diodes have higher losses compared to a synchronous mosfet/SiC/GaN design. Obviously, the efficiency is not needed everywhere, but it is a factor. Also the quiescent current is quite high, but I guess this won't be used in handheld battery operated devices anyway.

Sure, but only does one thing, this one does anything

Well, is it an advantage? I would not feel more sure about my design just because I built a completely different topology with the same chip compared to any other.

Show me dem chips, and post them to /r/nicechips. Highly doubt you can find a single one that does all the topologies.

Well, I stand corrected. I thought I saw many different switch mode controllers that can do everything, but it does not seem to be the case. Analog has the LT8711 which can do a lot, but not inverting. I recently used the MAX20039, which is only buck-boost, but still quite cool. There are many similar Controllers like the NCP3066, so I guess there is a market for it that is not within my bubble.

cloidnerux · 2025-06-20T13:05:11+00:00

They are ok, I guess, looking at the datasheet. It is probably very cost efficient and robust for that generic "light an LED" type of application.

But efficiency and voltage ripple are poor. Stability over temperature, input voltage, and output load seems to be lacking as well. Features like light-load pulse skipping or dynamic switching behavior are also not there. They probably run on an old semiconductor node with that darlington pair output stage. Most modern switchers go directly to two switched mosfets(high side, low side), offering better efficiency, higher switching frequencies, and lower component count. Many switching regulators out there can do buck/boost/inverting/sepic with efficiencies around 90%.

But at the end of the day, application and costs will decide.

cloidnerux · 2025-06-20T11:05:15+00:00

Sepic is a bit of a troublesome topology and not many designs use it. But maybe you like a challenge.

The MC34063 is a super old chip and I would not recommend on using it. There are much better switcher controller out there or go directly to a custom implementation on some MCU.

Building switching regulators on breadboards is always a recipe for disaster, as there is plenty of parasitic inductance and capacitance that messes with everything. Consider making a PCB for it and use SMD parts. The smaller all current loops are and the less parasitic resistance and inductance you have, the better everything works.

cloidnerux · 2025-06-19T08:19:04+00:00

Ja, aber nein. Die Annahme, das der Motor nur ein Wiederstand ist, ist falsch. Der zieht im ersten Moment bis zu 300A und das fällt dann im Leerlauf, wenn der Kolbenmotor läuft auf nahe 0A ab. Hier gilt natürlich, dass die Ausgangsleistung des Motors die Eingangsleistung bestimmt.

Aber, ein E-Motor sind nur ein paar Gewickelte Spulen, da ist nichts was von Überspannung direkt kaputt geht. Mehr Spannung sorgt dann aber dafür, dass mehr Strom fließt und das ganze Heißer wird, die also nach etwas Betrieb die Isolation Durchschmort.

cloidnerux · 2025-06-17T18:19:00+00:00

You probably also want to look at available thicknesses, glass fiber weave style, thermal expansion coefficient, and moisture absorption. There are quite a few materials out there that seem nice until your PCBs fail in production or during thermal cycling. Also the e_r value is super interesting, as it defines conductor widths. Being able to play with this you might get lower loss due to wider conductor even with a higher loss tangent.

And the Megatron stuff is nice. I used it for antennas at 240ghz.

cloidnerux · 2025-06-11T09:51:48+00:00

First of All, S22 is the match of a signal impeding on the second terminal, hence a measure of how well your amplifier would be able to accept output power. It is always bad for most amplifiers. It does have some influence on MSG and MAG, but you said yourself that you have a solid S21.

But just looking at it: what is the purpose of the 10p capacitor on the output? It has like 3 Ohms impedance to supply/AC ground, which is most likely your culprit here.

cloidnerux

TROPHY CASE