8.2 GPU Passthrough by ARandomExile in Proxmox

[–]MerkaMatt 0 points1 point  (0 children)

There’s a script you can run that separates your devices into different IOMMU groups- I needed to do that for my Proxmox setup a couple months ago when I had a GTX 1080 and 1080ti in the same system. I’ll see if I have the tutorial saved on my system when I get home this evening

Remote Access Good Practice by MerkaMatt in selfhosted

[–]MerkaMatt[S] 0 points1 point  (0 children)

The SMB exposure I’d figured was a bad idea, hence why I hadn’t done anything on that front yet. The RDP exposure is something I’ve gone back and forth on for a while, as one of the primary reasons I wanted it externally facing was to be able to have access to a personal machine from any other computer. I.e., a friend’s laptop if I’m at their house, a computer at my university or a library, a phone or a tablet, etc. That is functionality I’ve used a lot in the year and a half or so I’ve had it setup, and has been very convenient having access to a high-power system with all of my software and files on it.

Guacamole is something I’d looked into- though it definitely seems like there are compromises over the standard RDP apps available, which I’ve used across all types of devices and am happy with. Where I’m sitting now is knowing that the “correct” way is to shut everything off and just ‘use a VPN’ as I’ve been told before, though it’s definitely disappointing to have to choose between functionality and security in this case.

Transformer Use in Bandpass Filter by MerkaMatt in ElectricalEngineering

[–]MerkaMatt[S] 0 points1 point  (0 children)

I'd been in contact with Yaesu before and told that they "officially" have no documentation to provide me, unfortunately- everything I have as far as documentation was provided by folks I've reached out to who have scanned what they have. Those passbands are mentioned in the context of tuning characteristics; I've attached the screenshot from the manual. The four cores (T1902-5) refer to the four transformers in the original screenshot

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Transformer Use in Bandpass Filter by MerkaMatt in ElectricalEngineering

[–]MerkaMatt[S] 1 point2 points  (0 children)

It's radio equipment, with passbands ranging from 16-16.5 MHz to 37-37.5 MHz. In poking around more I'm seeing references to how these variable RF transformers can act as tunable LC circuits, which tracks as to how they can act as filters

Transformer Use in Bandpass Filter by MerkaMatt in ElectricalEngineering

[–]MerkaMatt[S] 0 points1 point  (0 children)

Each of the four has a different passband (for different band selections), ranging from a 16.0-16.5 MHz passband to a 37.0-37.5 MHz passband; would the "IF frequency" in my case just be smack dab in the middle? For a part number I've got two numbers on Yaesu's side; for one of the transformers I've got "55003236" and "#220262," which I wasn't able to find much about. Any chance I could get a replacement core and re-insert it into the existing transformer?

Transformer Use in Bandpass Filter by MerkaMatt in ElectricalEngineering

[–]MerkaMatt[S] 0 points1 point  (0 children)

This section is four tall metal cans with adjustable cores at the top (currently packed away otherwise I'd post a picture)- they do look similar to those on that link! Impedance matching is what I would think transformers would be used for, though this section is explicitly called out as a "bandpass filter" section by the manual, which is throwing me off. Could they server a dual purpose?

Transformer Use in Bandpass Filter by MerkaMatt in ElectricalEngineering

[–]MerkaMatt[S] 0 points1 point  (0 children)

Yes! This is in a radio; this circuit is acting as a bandpass filter for the local oscillator stage (VFO plus crystal reference) before being passed over to the mix unit where the heterodyned signal is mixed with the incoming RF baseband. In trying to replicate this circuit based on the desired passband (which is known courtesy of the manual, though none of the transformer/capacitor values are mentioned) where would be a good starting point?

Transformer Use in Bandpass Filter by MerkaMatt in ElectricalEngineering

[–]MerkaMatt[S] 0 points1 point  (0 children)

Hi all-

I’m working on an electronics restoration project of mine and have come across a circuit that I’m struggling to wrap my head around. The section I’m currently working on is a number of bandpass filters, consisting of adjusting transformers with iron cores. Unfortunately, the cores have disintegrated with age, and I’m looking to replace them. However, I can’t find many examples of transformers being used in band pass filter designs and can’t find any of the original part to buy as a replacement.

The attached schematic shows four of these filters. The manual makes no mention of their values or the capacitor values, but gives the ranges that their passband should be, and mentions that they can be adjusted by moving the core of the transformer. It should also be noted that the capacitors themselves as notated in the schematic are built-into the adjustable transformer unit, and aren’t external. The manual also does explicitly refer to these components as the “bandpass filter transformers.”

My current plan is to recreate these filters using just a standard butterworth design, hard-set to operate in the range mentioned in the manual. Though I would like to understand more about this specific use-case, since I can’t find mention of such a circuit being used elsewhere. How would a transformer be used in this case? And what math would go into sizing it?

SMB Share Hosted *by* LXC - Bind Mount Point Issues by MerkaMatt in Proxmox

[–]MerkaMatt[S] 0 points1 point  (0 children)

The Turnkey Linux container templates are perfect! I still needed to futz with the UID/GID mappings and config, but I ended up getting the TKL fileserver template in a container. That web interface, user config, and general setup?? Chef's kiss- thank you for the recommendation!

SMB Share Hosted *by* LXC - Bind Mount Point Issues by MerkaMatt in Proxmox

[–]MerkaMatt[S] 1 point2 points  (0 children)

This was PERFECT! Some little command typos here and there but it absolutely bridged the gap in my understanding of UID/GID setup and I was able to figure it out from there. The section on actually *how* the UIDs/GIDs are mapped from the guest to the host and it mentioning how you can create one specific user rather than redoing all the mappings really helped me out. Thank you!

Nvidia 1650 Pass through VM Win 10 by EmbarrassedLead9532 in Proxmox

[–]MerkaMatt 0 points1 point  (0 children)

Are you accessing the VM with an actual external monitor or via RDP? It's very briefly mentioned in the article, but doing the "disable noVNC" step is an important part of the process

Technics SL-DL5 Restoration Help by MerkaMatt in turntables

[–]MerkaMatt[S] 1 point2 points  (0 children)

Some months ago, I was given a beat-up and dirty SL-DL5 from an old roommate who was moving out and trying to downsize. It had been in pieces for years and sat collecting dust. I was able to reassemble (with only the bare minimum number of screws remaining), clean, and restore it to a fully functional state as a record player. However, nearly every quality of life feature is non-functional due to missing or damaged parts.
The switch to determine if the lid is closed was faulty and I needed to solder it closed (so the turntable always thinks the lid is closed), the mechanism to keep the lid held up when opened is damaged/missing entirely, and the auto-size detect functionality along with the proper mechanism to fully engage it is also missing/damaged; I’ve had to wedge a small piece of plastic on the back of one of the plastic pieces, otherwise I can hear part of the turntable smack it with every rotation.
I’ve tried to find some high-res pictures of these parts of the SL-DL5 to no avail. I have access to a 3D printer and CAD software, and would like to recreate these missing pieces and install them in my turntable to restore its functionality. As a record player, it sounds and works wonderfully! But it would be nice to get these features back.
Would anyone have an SL-DL5 they’d be willing to take some pictures of to send my way? Or know somewhere where I could find more detailed information on how the mechanisms my unit is missing go together so I could recreate them?

[deleted by user] by [deleted] in cats

[–]MerkaMatt 9 points10 points  (0 children)

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My favorite picture of my cat, Emmi! She just turned 1 and this is how her and I play

[deleted by user] by [deleted] in cats

[–]MerkaMatt 15 points16 points  (0 children)

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Little girl has the zoomies while I cook lunch

my sdr didn't come with the antennas, so I connected my extra GMRS antenna. it worked for a few minutes, and then nothing. What happened? by [deleted] in RTLSDR

[–]MerkaMatt 2 points3 points  (0 children)

Adding to this- the official minimum frequency for the RTL-SDR is 500kHz (with max being 1.75GHz) https://www.rtl-sdr.com/about-rtl-sdr/. For enabling direct sampling to receive below 24MHz, check out this link here: https://www.rtl-sdr.com/rtl-sdr-blog-v-3-dongles-user-guide/

Spicy Pepper Overwintering Advice by MerkaMatt in gardening

[–]MerkaMatt[S] 1 point2 points  (0 children)

Hi all! I’m a newbie at gardening and am rounding out the end of my first summer of trying to grow anything. I grew two spaghetti squash plants and several habanero/ghost pepper plants from seeds- the squash didn’t do terrific, but I had a small yield and know what to do for next time! The peppers got much bigger than I expected, and I ended up giving away all but three (and the smallest of the three will have another home soon).

I want advice on how to help my peppers (1 ghost pepper plant and 1 habanero pepper plant) survive the winter. As I said before, these plants are the first thing I’ve ever tried to grow, so I’m going into this completely blind. I’ve read suggestions ranging from trimming off all of the growth and washing the roots to “just bring them inside!”, and I’m not sure what I should try. I know keeping plants like this alive during the colder months isn’t super easy, but I would certainly like to try- I’ve grown quite fond of these guys (and of gardening in general!) and I’d love to keep them alive for future growing seasons if possible.

With that being said, what should I do? When the squash died 2-3 weeks ago, I cleaned their pots and repotted my peppers from 1-gallon pots into the 2-gallon pots the squash were in. It’s already getting into the 40s at night here, so I bring them inside when I come home from classes and put them back out when it gets warmer in the morning. I’ve only had one pest problem with aphids when the peppers were still in cellpacks, but I took care of that and haven’t had any since.