Kris\Slyka (@slyka.pawb.fun.ap.brid.gy)

@slyka.pawb.fun.ap.brid.gy Oct 10, 2026, 12:28 PM

using tvsim I can finally capture this awful camera in all it's glory, including it's "random interlace", where the horizontal and vertical sync are completely disconnected from each other and the scanlines just kinda wander up and down the screen. you might have to watch it in full screen to […]

@slyka.pawb.fun.ap.brid.gy Oct 10, 2026, 12:24 PM

picked out my best horror themed webcam for october. one for the scanline lovers.

@slyka.pawb.fun.ap.brid.gy Oct 10, 2026, 9:47 AM

@brouhaha oh yeah, I mean, bad vendor software is unfortunately not anything new. But this company seems to be going *hard* on the AI stuff from everything I've seen, so I have no reason to expect them not to do the same thing for their firmware

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 12:36 PM

time to pick another one of my 15 cameras as my webcam, I guess… should we go clean and crisp? maybe with high IR sensitivity to make my skin look even more pale? or something real scrunkly and wide angle? maybe even something with color?!

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 11:57 AM

unless I know somebody with an X-Ray machine who wants to take an image of the internals for me 👉️ 👈️

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 11:48 AM

man, that really sucks cause it probably means the amplifier hybrid is dead, which is going to be basically impossible to replace :/

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 11:45 AM

well, fuck. same peak and same oscillation when the tube is connected with the J112 as with the KP303E…

Screenshot of my scope showing the same peak in the noise floor of the preamplifier around 10MHz.

Screenshot of my scope showing the same oscillations as before

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 11:25 AM

looking at my collection of JFETs (which is kinda small, tbh) I think the closest thing I have is a J112? I'mma try that.

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 11:20 AM

So, as far as I can tell from the data sheet we're looking at a noise figure of no more than 4dB into a 10kΩ load, a gain of at least 4mA/V and a threshold voltage of no more than 8V, all at a drain-source voltage of 10V

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 11:03 AM

so I think I'll see if I have some kind of vaguely fitting replacement for the KP303E input JFET cause at this point that kinda seems like my last option here…

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 11:02 AM

Adding additional low ESR capacitance in parallel to the existing electrolytics also has no effect on the oscillation.
Adding additional capacitance in parallel to C10 does make it quite a bit worse and adding it in parallel C6/C7/C11 shifts the frequency of the […]

[Original post on pawb.fun]

Schematic of the preamplifier in question

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 10:51 AM

ok, doing more poking at the video preamp and looking at things on the spectrum analyzer. as I've already noticed yesterday disconnecting the wire running to the tube target ring kills the oscillation, but not actually in the way I suspected. I thought it was […]

[Original post on pawb.fun]

Screenshot of an oscilloscope view of the noise waveform coming from the video preamp with the pickup tube disconnected. It's got a strong peak around 10MHz

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 10:04 AM

@1000millimeter it's quite something for just wanting to post a comment under a wiki article, isn't it?

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@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 9:45 AM

also, love that their support consists of: * leaving a comment under their wiki articles, for which you need to log in with your github account and give them full write access to all your repositories * posting to their subreddit, which has been unmoderated and is currently looking for new […]

@slyka.pawb.fun.ap.brid.gy Oct 9, 2026, 9:38 AM

guess I'll stop with this FPGA board until I hear back from their support (assuming that ever happens) and get back to fixing old cameras. At least that doesn't involve having to deal with USB…

@slyka.pawb.fun.ap.brid.gy Oct 8, 2026, 9:47 PM

you need to get the flange focal distance on your camera right or you might end up focusing beyond infinity and you *really* don't wanna see what's out there

@slyka.pawb.fun.ap.brid.gy Oct 8, 2026, 8:18 PM

what's a unix sysadmin's regular breakfast? cronflakes

@slyka.pawb.fun.ap.brid.gy Oct 8, 2026, 3:08 PM

*gives up, eats a pizza*

@slyka.pawb.fun.ap.brid.gy Oct 8, 2026, 2:06 PM

ok, pretty sure their USB stuff is just fucked? it replies just fine to the first GET DESCRIPTOR request (pretending to be an FT2232), then the host sends a GET DEVICE QUALIFIER request and the thing just dies until it's power cycled…

@slyka.pawb.fun.ap.brid.gy Oct 8, 2026, 1:40 PM

tang nano 9k? more like… taint nano 9k.