"But nevertheless the instrument shouldn't be too susceptible to component defects or whatsoever."
If it is not what it states it is, I feel cheated. However there are warranty laws and they are there for a reason. I don't have any doubts that whatever the issue is, it will be solved in the future but for reasons of profit margins and other costs it is not feasible to replace every product already made especially for a small business. If you buy expensive stuff and it does this, they deserve to be out of business if they don't take responsibility. That is why they cost so much. That is why a simple screw can cost you more than a whole motorcycle. If that screw fails you are as well, because the whole plane is disintegrating at those speeds.
In general I agree with you, Igor.
Regarding scopes, there is (for me) no doubt that you get real quality only if your budget isn't tight. I still possess the successor of your MegaZoom II scope (a MegaZoom III), bought 2014 as used instrument at around 1.500 € (54641D). It lacks colour and USB, but MegaZoom is fantastic (as a user experience - e.g. also does it on stopped traces), but the robustness and quality are equally well superb. Not to forget the true analog-like display representation (see attached example image, SMPS waveform over full AC mains time slice). Having said that: I cannot believe that those cheap instruments out there can be trusted in some aspects, e.g. drift - or display representation quality. And yet I'm targeting again a used Keysight instrument in the 'colour' class (DSO5054 or 6054). Used these are offered for approx. 5.000 €, while new stuff from cheap vendors with that 500 MHz BW offers far more memory and higher GSPS while costing less than this over 10 years old Keysight equipment.
In the case of Dave B, well, my view is that you indeed may not expect high quality, but stuff that can be used quite well at low cost can make sense if the instrument is used only sporadically or as an accompaniment to other instruments, and if you accept e.g. accuracy drawbacks. But nevertheless the instrument shouldn't be too susceptible to component defects or whatsoever.
Rob
On Sat, 19 Apr 2025 10:42:37 +0200, Igor Feher via <igor.feher= [email protected]> wrote: I'm sorry to hear you had bad luck. I can give you my perspective, if you care, but can't offer any real help, it is beyond me.
My boss ordered me a signal generator for $80. At the same time they offered me a 15+ year old signal generator that costs over $5000 cheap, with scratches, well used. I declined it because it is too expensive. Chinese one does its job but as I generated sparks about 0.5 to 1.5 MV everything around the spark was glitching, even CPU controlled power supply a laboratory equipment US made, it however did recover after every glitch. 54602B HP scope (I assume you are all familiar with the series) however had no issues and they are on top of each other. In other words I expect a cheap one to be cheap. Lab equipment
costs as much as a house.?
As I worked in a factory as a developer and research engineer at the same company, I can tell you how many stupid things can go wrong . For example some dumb worker leaves fingerprints on a PCB (I also did that once, but while investigating an issue that was already there so only one board was ruined), factory delivered PCBs with dust, engineers that don't RTFM, component specifications change slightly between batches. There is a lot you can only learn from past mistakes so testing lab stuff takes ages and therefore costs a fortune.
Interesting to read everyone's comments regarding your purchasing quandary.
Just to add my "two penny worth",
I have a TinySA ULTRA that was purchased just over 1 year ago from the UK official distributor and cost ?159 and I expected it to be the 'genuine' article.
I bought it to check that my CMT2110 micro transmitter design's output filter was supressing RF spurii to the required levels. (which it was).
This week I started to use it to align a Local Oscillator multiplier strip when the screen froze.
My TinySA ULTRA has probably only 25hours running time in the last year and the rest of the time being stored in t's protective sleeve and in its original box.?
It still looks like 'brand new' and yet appears to have irrecoverably failed.
?It's clearly a known issue as it's right at the top of the Wiki fault finding page
However it's a "try this or try that" response NOT actually a description of the exact engineering issue or how to permanently fix it!
So...
Whether you go for Aliexpress or the 3x more expensive 'Genuine' distributor, you cannot be guaranteed that your purchase will last any longer :-(
So now I share your quandary.........
Dave
?
|
