I should have mentioned in the video, yeah the caps were likely the culprit on the RF PSUs. I didn't have any on hand though and those transformers were on their way out after 20+ years of uptime. I kept all the old internals for the next time I order a round of caps though to fix them someday!

@gorak9000

4 ай бұрын

Transformers don't "wear out". Capacitors do, specifically electrolytic ones do. The caps had already been changed in one of those units, as they were different than the other one. Chances are someone put some garbage quality caps in as a replacement and they failed again. If you have noisy transformers, you need to encase the windings in resin - that will eliminate the mechanical humming. Replacing all the electrolytics in those modulators would eliminate all of the electrical "humming". That said, analog cable is pretty useless these days - you'd be better off getting digital cable modulators and producing your own digital cable channels, though it's a lot more involved to get a multi-program MPEG2 TS generated and output as an ASI stream that you can feed into a digital cable modulator.

@paladinbirdy6032

4 ай бұрын

I just recently replaced every last electrolytic capacitor on my BT modulator's power supply board, and the whole thing feels good as new. Took 2 hours max. Make it a video some day!

@unavailablenumbers

4 ай бұрын

@@gorak9000I used to work at an MSO for some years. Those Blonder Tongue units? Yes. The transformers do wear out. It's a very common problem with them. They're junk units with no resin, minimal potting, and the big problem? Look at the video - the plates aren't screwed. They're only crimped. These ran for years upon years in very, VERY hot racks. Thermal expansion with dissimilar metals. That's why the buzz stopped with the screwdriver; enough pressure to stop the plates vibrating. These things were built to COST, not quality. I didn't work on the RF side, but these things were so notorious for transformer problems that the repair people kept stashing boxes of spare transformers in our cabinets. It only got better when they switched over to the MPEG2 stuff, which was far less power sensitive. If you look at how the MIPS-12 racks are, you can really see just how 'cost-reduced' this stuff really was. ("Power backplane? Ground plane? Nah, we'll use chassis ground and leftover DB37's with bare wires.")

@nickwallette6201

4 ай бұрын

@@unavailablenumbers Chassis ground? The power cables were home-run from each of the blades to the PSU. That little 3-terminal connector is Gnd, +5, +12. The only thing left to the chassis is shielding -- which you want -- and maybe a little bit of passive heat spreading -- which you also want. The DB37 is a little howya-doin, but it works. Depending on who manufactured it, they're usually rated at about 1-2A per pin, and the quoted load figures for each rail on each blade tops out at like 800mA for the stuff with lots of digital controls. As for transformers and lack of resin, that's not uncommon either. It's not necessary for isolation, just makes them a little more mechanically quiet. When you're putting these things in an industrial rack, that's not usually a concern. Even if they do eventually rattle apart, as you said -- they "ran for years and years in very, VERY hot racks." If that's not a testament to adequate (if not above-and-beyond) engineering, then I don't know what is. It's hard to point at the micro modulator packages, with their die-cast metal forms, and see much evidence of cost-cutting. Granted, they're not built with much in the way of creature comforts or extraneous belt-and-suspenders design. Each blade uses its faceplate to back-stop itself. If you remove the front face, it'll slip right through the rack to the other side. The faces are plastic, not brushed aluminum. The F-connectors aren't chassis mounted -- they're actually molded into the chassis. If you strip one, that's it. Get a new blade. Maybe you could call all of this "cost-cutting" but I actually don't. It's no-nonsense manufacturing. It has exactly what it needs, nothing more, nothing less. The proof is how these things will run for two decades solid until they're replaced with something else, and then retire down in an enthusiast's basement with nothing for maintenance but new caps and maybe a couple squirts of fader cleaner on the pots. If they're engineered absolutely perfectly, they'll perform flawlessly for about two hours longer than their required lifespan, then they'll spontaneous combust or crumble into a pile of e-waste. Anything more is technically wasted money.

@unavailablenumbers

4 ай бұрын

​@@nickwallette6201 nope; I got quite the crash course in the MIPS family. You think it's GND,+5V,+12V but actually it's pretty much a floating ground. Because it goes direct to the PSU, which by that point was a PCB that had a flimsy aluminum shroud tacked on. So to 'fix' it, there's a ground jumper attached with self-tapping screws between the chassis portions and the cards also chassis ground. (Can you say "ground loop"?) So invariably, every one ended up significantly modified to delete one or more ground paths. And by "years" I mean it's MSOs. A lot of Blonder Tongue's junk had a lifespan measured in months. But instead of replacing badly designed junk? They'd just keep repairing it. For years upon years upon years. What, you think it runs reliably for years? Hell no. Not even remotely. But these are companies that 'refurbished' universal remotes to save a whole $2.37. Companies that were putting 'refurbished' 40GB IDEs into SA 8000-family DVRs more than a decade after the last was made. Companies that to this day have SA signal integrators in service that haven't been sold since 2013. Companies that still have 762MHz SA-branded Gainmaker's on the poles and would rather swap in Chinese knockoff internals with counterfeit parts than even consider replacing. As a rule, every MSO and cable company on earth will throw endless repairs at the worst junk imaginable, just ignoring the costs. And do anything to use it at least 10 years past the point any sane person would have scrapped it. They don't dump anything until they have extracted every last penny by hook or by crook, it's so obsolete they can't possibly throw it into any headend, or it's literally broken beyond any possibility of repair.

The guy is literally cosplaying as a 90s TV broadcast station and I'm loving every single second of it

I have no idea how I ended up here but this is exactly the kind of content I live for.

@VagueDustin

2 ай бұрын

Well said!

This is absurd, convoluted overkill. I love it.

@anonamus604

4 ай бұрын

lol it make me so frustrated

@kumbah2006

2 ай бұрын

But, you have to admit it's a great way to shuttle content from your server, or other playback device, to your TV set! Might be convoluted, but it really is the way to go ...

These were probably from on demand systems from a hotel. I was a switchboard operator back in the 80s and you could purchase a movie in your room. They would tell you to switch your TV to a certain channel and the movies offered would play through different boxs on a loop forever until the tapes were changed. There was a switching system that opened up your room for a certain movie. It was a crazy system of racks with multiple VCRs playing movies over and over and over.

Man, this would be a dangerous adventure for me. I'd be trying to replicate TV from the 90's to the point that you'd have to look out the window to ensure you didn't just time travel. I'd need a LOT of RF converters.

@redsquirrelftw

3 ай бұрын

I was thinking the same, I would go down the rabbit hole setting up automated programming and even a TV guide channel. Maybe even throw in commercials for old time sake lol.

next setup you should crowdfund $10 million dollars to launch satelite and broadcast your cable to the satelite, then receive it through a dish to watch on tv 😂

@clabretro

4 ай бұрын

😏

@kumbah2006

2 ай бұрын

Why not just connect with Elon, and find some way to use Starlink to do it? Oh wait, that's for internet, but would it work?

Home broadcast plants like these get way more complicated way faster than anyone is willing to admit. Your setup is giving me ideas on how to augment my own.

Output levels from those tuners should be lowered as far as it will go and still give you a good picture. Analog Cable TV should be in the range of 0-15 dBmV, and those modulators can put out 100+ dBmV. The front test port has a 20 dBmV pad to lower it an additional 20 dBmV below the output on the back. Any unused ports should be capped off with 75ohm terminators to reduce ghosting / reflections / ingress / egress of signal. I have a few of the rack mount versions like this, but also a cage that takes about a dozen modulators and a shared powersupply for them. Was planning on doing a big CATV exhibit at VCF Southeast in 2023, but ran out of time & energy to fully execute the setup. I really appreciate the effort you've put into getting good video output from the Pi's as that can be a pain with the TV output and video codecs being cast aside by some of the later software available for it. I have a video playout server I cobbled together with some 4-output Aja Kona cards, but never could get all the outputs to reliably work at the same time. Of course, commercial software that can use the card for output and feed it blank frames between videos is stupidly expensive, and my tiny disaster of GraphEdit's code export doesn't smoothly transition from one video file to the next.

@clabretro

4 ай бұрын

thanks for that info! I didn't mess with the adjustments at all so I'll do that. I really need to get the right equipment to test all this stuff. your setup sounds awesome, I hope you're able to get it to VCF someday!

@manitoba-op4jx

4 ай бұрын

yea, too high and your recievers might be damaged

@kreuner11

4 ай бұрын

how high is 100 dbmv? Googled a converter and it said 100V but it can't be right

@button-puncher

4 ай бұрын

I think you may be getting your units confused. 100dBmV would be about 100 watts of power. (An insanely high level.) +100dBuV (+40dBmV) would be in the range for a B&T modulator. dB microvolts is 60dB higher than dB millivolts. Single channel modulators had a +55dBmV output. Agile modulators were +45dBV. IIRC.

@GrizzLeeAdams

4 ай бұрын

@@button-puncherI'm sure you're correct. its wonderful how different scales are used for different equipment attached to the same cables. Throw in a cheap noname coax meter that probably isn't calibrated coming from the factory, and it just adds more confusion. The only time I've used one of these modulators in production was to send a video feed 200ft (the equipment was pre-existing, and I had to do calibration of the power output via radio to someone who could turn the pot for me while I stared at the screen). As soon as I could, I replaced it with HD-SDI and reused the same coax. The musicians were much happier with a 1080p live feed instead of the 480i they had with the modulator. :D

Was likely just the filter caps on the PSU, there were some bad runs in that era that do not age well.

@soniclab-cnc

4 ай бұрын

went right to the comments to see if this was suggested... transformer likely is fine.

@clabretro

4 ай бұрын

I should have mentioned in the video, yeah the caps were likely the culprit. I didn't have any on hand though and those transformers were on their way out after 20+ years of uptime. I kept all the old internals for the next time I order a round of caps though to fix them someday!

These rack mountable screens for monitoring are just… perfect, peak homelab rack aesthetic… loved it!! even that I don’t have rf transmission going on, I would love to have these to display the esxi status and the vms…

@markgilbert5856

4 ай бұрын

or even a home assistant dashboard

It is interesting that a simple little switching "wall wart" makes cleaner power than the once-supposedly-high-end power supplies that were built into those units. Well, those are worn out now but not the adapter plugs. So... nice little jimmy-rig there!

Absolutely brilliant. Also, what a breath of fresh air from the normal boring homelab channels.

@clabretro

4 ай бұрын

thanks!

I bet the hum was caused by ancient capacitors slowly drying and stopping "capaciting". The classical thing to do would be replacing them, maybe also adding some polymer caps in parallel 'cause there is a lot of space, and they don't dry. The corrosion is caused by evil silicon-glue-thing they used to glue the LED to the panel. Resistors value can be increased to the point where LEDs glow still visibly, while not piercing the eyes at night (4.7 - 33k?). Newer LEDs are brighter by a trick of moving their wavelength a bit towards orange, which looks still red enough, but requires less photons for eyes to notice. Aaand as always: pleasure watching 😸

@clabretro

4 ай бұрын

Totally! I should have mentioned, I didn't have extra caps to try. So out it all came haha. I kept all the internals whenever I order caps to try fixing it later. I also think you're right about the glue, other folks have mentioned that as well and it explains why both had that issue. Thanks for watching!

I thought I was the only one doing this! I am located in Australia, I use 5x MPEG2 DVB-T Digital Modulators & 2x MPEG4 DVB-T2 Digital Modulators all hooked up to Apple TVs, streaming content on each channel from YT, Rumble, Plex etc. I also have 5x Stereo Analog RF Modulators tuned to the digital channels with separate OTA STBs hooked up using my home coaxial cabling. I also use the same coax for MoCA and there are no issues. The signal gain is so high it overrides my local OTA channels (of which I never watch!)

@clabretro

4 ай бұрын

Very cool! Sounds like a sweet setup.

Btw, one suggestion is that you could use that text imposer generator to periodically display information about what episode is playing. This of course would require a lot of effort to interface, but would be possible (and very cool)

@clabretro

4 ай бұрын

yes! that's something I want to do eventually, I meant to bring that up. it'd be cool to have the idea of "hooks" where you could register things to happen before or after episode transitions

@manitoba-op4jx

4 ай бұрын

@@clabretro there are composite video switchboards and text/graphics generators out there with serial interfaces. one of those maybe?

@ultraswank

4 ай бұрын

@@clabretro I guess you could also create a hook when an episode ends and "inject" a manual video file with a station logo or similar and leave space in the end to overlay "coming up next" info and which episode will play.

@alextirrellRI

4 ай бұрын

VLC can already do this somewhat simply, but you have to have the metadata clean on each episode.

@shaunclarke94

4 ай бұрын

Then you can use some IR receivers and do a full menu system.

Something you might look into. MPV is a video player that doesn't need an xorg session to display video, there is also a shim that can be used to control MPV running as a Jellyfin cast device. This would let each "channel" show up as playback device in the jellyfin webui or mobile app.

@rhfweb

4 ай бұрын

This as well. :)

@clabretro

4 ай бұрын

Sweet, didn't know about MPV. I'll check that out.

@microcolonel

4 ай бұрын

​@@clabretroyeah, and playing directly to the video output through KMS/DRM is more efficient.

@itstimeforMario64PLAYER

4 ай бұрын

Yeah I saw a Ubuntu desktop. Please consider that

@JacobSmith_emjds

4 ай бұрын

Man I've been looking for something like MPV for ages. Big thanks.

“No data sheets with this one” made me chuckle

We had Blonder Tongue gear in our studio back in 1999. Always thought it would be a great band name.

Ahhh reminds me of my working days. Built so many head ends in my time. Plenty of people already told you about replacing the caps. Have fun with your home lab. If you ever get into having 500 channels at home make sure to equalize the channels.

@OurSpaceshipEarth

24 күн бұрын

Yeah normalize to -90DB or w/e.

Congratulations, you've built a 90's era analog cable TV headend! (you're actually not very far off from the real thing!) In a "real" analog headend, you have racks of satellite receivers that receive the networks, there's a web of cables connecting them to RF modulators, and then there's a combiner that aggregates all the RF from the modulators together. A large signal amplifier is the last step before it goes to the street and out to subscribers' homes. Analog systems didn't have much in the way of access control, they were either filtered at the customer's house or their analog tuner boxes had filter chips that would "block" specific channels that the customer wasn't subscribed to. For premium channels (like HBO, everyone knows the wavy pictures on unsubscribed premium channels and late nite TV, lol), these channels were sent to the street missing a sync signal. The set top box had to synthesize a sync signal in order for the TV to display it properly. Of course the tech now is radically different (QAM/QPSK, and MPEG compression), there's communicating set top boxes, and billing platforms to authorize channels/packages, etc. so a lot of the analog stuff just isn't applicable anymore. If you want to get fancy with it, find some combiners and see if you can get ahold of a CMTS, then you can shoot high speed data over the same coax for your TVs just like the cable companies do. I'd also recommend getting a signal meter if you want to go deeper. It'll help make sure you keep your signal levels in check, both for high speed data and for analog/digital television. Welcome to the rabbit hole!

@clabretro

4 ай бұрын

Definitely been thinking about getting a signal meter, it'd be really useful. And I've been eyeing CMTS units, but they're way too expensive haha.

The Buzz in the Channel 13 modulator is most likely the capacitors on the power supply board. They would be tired as these things are left on 24/7 for many many years.\ Likely be around $5 to replace the two electrolytics in the original power supply and it would work perfectly again. That black stuff around the LED is probably what is left of the glue. That original power supply looks like it has been played with a few times. The vibration in the transformer will just be the laminations of the core separating, again due to time. You could reseal it or wedge something under the transformer bracket to stop the vibrations :)

@clabretro

4 ай бұрын

Yeah upon further inspection of that very loud transformer, I think I can tighten things up to quiet it down. Whenever I order a pile of caps I'm going to include some of these to try to fix one of the original boards.

The little "weird" insulator for the 12V @6:42 is an RF feed-through capacitor. It only allows DC to go trough and blocks the RF signal the modulator generates and prevents it from going into the power supply and going out of the box and turning the power supply cable from turning into a TV transmitter antenna. The mechanical buzzing from the transformer can be fixed by putting some glue between the metal case of the transformer and the internals. To fix the audio noise its just a case of replacing the capacitors. The "burn" mark around the LED is old glue that turned conductive and corrosive over time and eating the LED legs. So in any device you open up and see brown glue on any parts take that glue out before it starts eating parts and turning into a short circuit.

@clabretro

4 ай бұрын

ah-ha I figured that insulator served a purpose beyond just getting the wire past the case wall. I think you're right, I took a closer look at the very loud one off camera and I might be able to tighten space between the case and the internals as you describe. I kept the old power supply internals for whenever I order a round of caps, I'll try re-capping someday.

this pass through is normaly made to prevent EMF Problems. I would asume here the main intention is to shield the mains from the HF Electronics so you don't accidentally induce HF on the mains. Also this ceramic passthrough components in the Metal shield some times have built in filters. The 16V is probably ok even though i wouldn't use it for HF Applications. I would asume the Voltage drops when a load is attached.

That "terminal" on the wall between the power supply and modulator PC board is a feed through capacitor. Very common in RF gear. I keeps RF from reflecting back on the power supply which could actually be impressed on the 120v AC if high enough in level. Of course the feed through capacitor also keeps RF from the power line getting into the modulator.

@clabretro

4 ай бұрын

ah-ha, interesting!

@lbgstzockt8493

4 ай бұрын

I may be backwards on this, but wouldn't a cap let the RF through and instead block any DC component of the signal? I would use an Inductor as an RF block while letting DC pass, which seems like the way to go for a PSU.

@andydelle4509

4 ай бұрын

@@lbgstzockt8493 The capacitor is not built they way your are thinking. The solder terminal is a straight through wire. The capacitor is between the wire and ground which is soldered down

@danzup

4 ай бұрын

Really You do not know about feed through capacitor? You need to learn more about RF componenta and electronics.

@JM_Solo

4 ай бұрын

Yeah when we got to this point of the video and he started doing a lot of guesswork I lost interest. Why tear into these old modulators if you’re not sure what you’re really looking at or doing? Not the most educational. I’ve serviced a couple of these to replace caps and always made sure to have schematics on hand. We have to use them to feed our rudimentary AV signal to the local cable company to broadcast a church service twice a week. They insist we use this ancient tech rather than just upload video files or stream to a server and let them do the conversion on their end… annoying.

Many people for years have been using that screwdriver trick when working on cars. Never thought about it for electronics

@clabretro

4 ай бұрын

probably safer on cars ha

@1993MAZDAMIATA

4 ай бұрын

@@clabretro yeah I would assume so haha

I love it when people start cooking and come out with a genuinely interesting homelab concept. I wanted to do something similar in college dorms where we had cable hookup but it was unserviced. RE: student-run cable tv that probably only reached one building over. I couldn’t find any transmitters cheap enough back then and this video described perfectly what I’d have wanted LOL. This is great.

@clabretro

4 ай бұрын

ha that would've been awesome. thanks for watching!

I've been on my hunt for something like this for ages, a few months back I saw my first video on this setup and I'm prewiring my new office with cables specifically for this. Thanks much!

@clabretro

4 ай бұрын

nice!

Vlc has a built-in web interface that can be enabled in the settings. The ui is a bit ugly but it works. You can control playback, see and modify the playlist and if you have flashplayer you can even preview what's currently playing

Interesting stuff. I work in K12. Some of our schools still have Blonder Tongue devices (not rack mount ones) with coax still connected to them. I think they're still powered because they feel a bit warm to the touch. I was initially perplexed as to why those where there then I remembered (from when I was a student there) that most classrooms had a little TV in the corner of the room and they had cable TV service. That has been long discontinued (at least 10+ years) but they never ripped out the cabling or equipment from the main server rooms.

@Chevroletcelebrity

2 ай бұрын

what do they used now for the tv

@JJFlores197

2 ай бұрын

@@Chevroletcelebrity We don't use TV service any more. We had SmartBoards with projectors installed about 16 years ago. And over the past 6-7 years, our district has been very slowly upgrading from these old SmartBoards to IFPs -Interactive Flat Panel displays. Essentially they are very large (75") touch screen TVs that have an Android computer system built in as well as other connectivity options. A typical setup consisted of a teacher station (desk) somewhat close the IFP and an HDMI and USB Type- A to B cable is run from the teacher station to the IFP. Now we're trying to be "revolutionary" and changed vendors and use some wireless casting devices which intermittently work.

@Chevroletcelebrity

2 ай бұрын

@@JJFlores197 whoa 😲

12 Volt center positive barrel jacks, all of that one specific size, is the most common power cord for home networking and a few other things all over my house

This was so fun to watch. In high school, we had an in-house CATV feed fed by a Blonder Tongue unit. While we used IP as well, there was a certain coolness of sending modulated RF to all the classrooms. But oh man, was KZread so much easier (and better quality) for everything once we switched. Long live coax!

That DC power isolation connection through the aluminium box is standard construction with these modulators. These are cable headend modulators, and there are usually dozens of them all mounted together in one rack, so they attempt to minimise the RF intermodulation and RFI between the devices with construction techniques such as that.

I love this. Broadcasting on your own internal cable channels is awesome on its own, but the rack mounted triple monitor makes this bad ass. I'm inspired.

ANY transformer on mains is going to buzz at 60hz (in USA), its not an indication of a problem of the transformer, though well made transformers will do a better job of isolating it fairly well, but it's physics, the 60hz cycle of AC is going to make all them coils move ever so slightly, and hence make a 60hz hum that you will hear directly from the transformer. The buzz you hear over the RF is most likely a bad capacitor that is no longer doing its job to block the the hum from getting onto the audio circuit. The switching mode supplies you are using are going to have switching frequencies far above 60Hz so its going to mask that bad cap because 60hz isn't making it into the circuit to begin with anymore.

doing things this way can give you an 80s to early 2000s experience on how we used to watch tv

Great video as always! Welcome to the land of RFI! Switching power supplies, cheap ones, can be extremely noisy. However, there are plenty out there that are designed correctly and won't introduce any noise. I run everything in my radio shack off linear power supplies, except for one 30A switching supply made by Kenwood, for supply of 13.8V to a transceiver. Ferrites will help kill some 60hz buzz as well. Some A/C filters work, some are snake oil. I think the transformers are oscillating. They could be delaminating too. The oscillating could be in the diode network, as they're breakdown voltage starts fatening up from time and heat. Go buy yourself a cheap mechanics stethoscope before you fry an ear off 😂

@clabretro

4 ай бұрын

Yeah and in the end was probably just the caps anyway! Those transformers probably weren't too long for the world anyway though. I bet these things have had years of uptime.

Put a ferrite core on the inside 12V input. Also on the audio input cable outside. I have always wanted to put my security cameras on a TV channel. It's output is HDMI. Putting your server on a channel is really cool in that you could take a wireless K&M to any TV and make changes. Just as easy to VNC from a laptop I suppose.

Funny, all these years, having kinda messed around with radio, walked around a local tv station...never occurred to me that the coax could become just another "input" you could use on the tv. Granted, there's not much of a reason to do this just for another input...but pretty intriguing, never thought of it that way. Didn't even cross my mind there was hardware to do this, but of course there is, how else would tv stations be able to function.

You really need a spectrum analyser to set these RF modulators up correctly. They will not produce an output without a video signal but will function without an audio signal. You will also need an RF combiner if you want to have a few of these modulators all with adjacent channels, otherwise you will get too much ingress between the channels. We have dozens of these at work for an in-house cable monitoring system.

@clabretro

4 ай бұрын

Yeah some legit analysis tools are on my list!

The original supply could possibly be fixed by replacing the old caps. More than likely they are going bad which is allowing more ripple when under load. A pi filter might also help too. And those bulkhead connections are standard for RF cages of that style.

@clabretro

4 ай бұрын

Yeah didn't have any caps on hand to try a simple cap swap. Kept the internals to fix later though!

2:09 The color difference is not because the black coating wore off, it's the dye in the anodised aluminium that faded because of sunlight :)

The removal of the transformer reminded me of the scene from Brave Little Toaster when the blender had its motor removed.

@clabretro

4 ай бұрын

😂

At 7:14 your first Power Supply was showing 16V probably because you were measuring with no load. And PSUs sometimes need some minimum load to self regulate

@clabretro

4 ай бұрын

Yeah good call!

@eDoc2020

4 ай бұрын

Those old-school PSUs are totally unregulated. Under 1 amp load it will probably be close to 12 volts but there will be unacceptable ripple for the sensitive circuitry.

A friends dad, who was a car mechanic, used the same trick with a broomstick to hear which cylinder was missing on engines that wasn't running right.

"Put your head and attach it to an open power supply circuit" great advice haha... That's actually a pretty neat trick

@clabretro

4 ай бұрын

As I was saying it I was like... "I should not be saying this on film" haha

Many newer RF mods will depend on the baseband video input being present in order to provide a channel output. This prevents the modulator from modulating static like they used to. That's why you will get a blank screen if the TV even locks the channel instead of static.

@clabretro

4 ай бұрын

interesting!

@nickwallette6201

4 ай бұрын

That was my thought as well. It seemed, though, that it was generating _something_ since the TV went from static to a blank screen when the mod was powered up. No audio without video though. Maybe it's just dependent on the video carrier? I know the ones that do BTSC / MTS Stereo require a present video source to synchronize the horizontal scan with the audio sub-carrier.

@Yohon5656

4 ай бұрын

Who makes Analog modulators anymore?

This is insanely awesome. Also those mountable screens are soooo neat. I'll have to go hunting for one someday.

Replacing the capacitors in the power supply would have been where I started to fix the hum. The electrolyte dries out over the years. Would have been a cheap thing to try before replacing the entire PSU.

@clabretro

4 ай бұрын

Yeah I didn't have any caps on hand, but I had all the other stuff I needed. I kept all the internals, next time I order capacitors I'm going to get some for these to try.

If you are going to daisy chain your 12v stuff, you will want to think about something that can handle the amperage. My personal favorite is Anderson Power Pole plus you can find 12v redundant power supplies for radio equipment that can be rack mounted. Also there's panel mounted plugs you can get and make things really nice.

@shaunclarke94

4 ай бұрын

But you'll want to fuse things. Powerwerx has the West Mountain Radio range of distros which were great and individually fusable.

I love sitting down and cranking out a project with some new code and maybe some hardware, it feels so satisfying.

I absolutely love this. Well done! I can't wait to set something up similar in my own house.

It would be funny to add in like a pre-roll advertisement setup for the true nostalgia

It kinda seemed like the hum you were getting out of those RF Modulators was the 60hz AC hum.. There should've been some smoothing capacitors on the power supply circuit built into those, they might've expired or possibly unlikely were left out? If you're looking for a super cheap +12vdc external PSU for these, you could easily use a standard run of the mill ATX PSU for it. Jump the green wire to ground which "turns on" the PSU, and all of the voltage rails will be active. Generally pretty clean power. I tool an old one and weeded out all of the non-12vdc wires, collected up all the grounds and all the +12vdc leads to a pair of binding posts on the chassis of the PSU. Have a couple of them, one runs a VHF Motorola Spectra radio I use on the ham band, the other is for general troubleshooting. Depending on the wattage rating of the PSU, they can put out some serious current and its really clean! BTW- Haven't forgotten about ya! Been absolutely swamped with work the last few weeks.🙃🙃

@clabretro

4 ай бұрын

I have a couple of Pico PSUs I thought about using, but went with the direct ac adapter just to see how it would go. To be honest I was thinking the ATX PSUs wouldn't have too clean of a 12v rail since it's just for spinning up hard drives and such, but I'll have to try that someday. Also no worries! haha

Good video, it reminds me of when I worked in a cable company, until now we continue using those same analog modulators along with the digital ones (Hybrid CATV). Some recommendations, first check the output power of these modulators, if they are very strong they could damage the TV tuners (10 to 15 db recommended). Also make a good ground to the rack to avoid potential difference between the TV and the Rack/Modulator. Another recommendation is not to replace linear transformers with switching supplies. Switching power supplies have a lot of switching noise at the output so it is not recommended in analog RF equipment.

All i can think is this guy is going to make a killer media empire in the apocalypse

The buzzing is from the windings inside the transformer. As these units have been powered 24/7/365 for years and years, the lacquer varnish on the wire windings in the transformers slowly gets loose from the heat melting them. After a while the back EMF from the transformer causes the winding to move (think electric induction motor) around the core, and they begin to make noise!

Scope creep...me 100%. It starts out great but then I slowly expand it... "I'll clean that up... Never". A man after my own heart with no lies

@clabretro

4 ай бұрын

every time

I think the PSU issues in both cases could be the electrolytcs in the PSU going bad. Both noise and excessive current can be down to bad smoothing caps.

@clabretro

4 ай бұрын

Yeah quite likely, I kept all the internals. Next time I order a round of caps I'll make sure I get some for these to try and repair one of the original boards.

I love the retro tech shown on this channel

Oh I’m excited for this one. The homelab cable is what originally brought me to the channel. I wouldn’t shut up a put it for a week.

Imho it would be better to make the original PSU work. It probably uses 7812 linear stabiliser or an LM317 and 2 smoothing caps. We can clearly see full bridge rectifier and 3 legged to220 package chip. Really not much can go bad over time with those, other than caps. Even if anything else goes bad it is really as simple as PSU can go. Also the transformer phisically buzzing shouldn't introduce any noise into the power. The difference is that most todays power supplies are switch-mode (non linear) and can introduce lot of noise. This noise and analogue circuitry (especially RF) usually don't play along. It's great that it worked out here but that's something to keep in mind in the future if it doesn't.

@clabretro

4 ай бұрын

thanks for the info, I agree. I kept all the old components in case I repair them someday, I figured they'd be much higher quality than any ac adapters I find.

@oskardzida

4 ай бұрын

@@clabretro Good call. I wouldn't be worried, it is clearly working well here. Either the circuitry is not "picky" or the PSUs are quite good. Also it is not as straightforward as the linear PSU being better, the setup with transformer and stabiliser usually uses more power and can have other problems. It is just good to have this at the back of your mind if things don't go well, if there would be any noise with plug-type PSU. Also there are some really good switching PSUs, and some big and heavy plug-type ones with transformer in. The latter can be AC, DC stabilised or unstabilised.

@andydelle4509

4 ай бұрын

Agreed. The power supply probably just has bad capacitors. Easy and low cost to fix.

They have the shorter power cables because long power cables are a pain to dress in the racks! So they sell them with the short cables that can go right over to the AC plug next to the rack unit elevation the unit is mounted into.

Ive been looking for something like this, specifically to have security cameras output available on local channels and some tv shows playing 24/7 on other channels. Thank you for such great instructions

@clabretro

4 ай бұрын

Security cameras were my original inspiration actually, ended up here for now ha.

Next up: clabretro calls supplies the whole neighborhood with custom channels via RF and this operation gets out of hand. 😂 And don't worry about the electricity bill, you're not even near our european kWh prices. Cool project and can't wait to see it evolve further, like putting in period correct commercial breaks into the loop.

@clabretro

4 ай бұрын

haha. yeah been thinking about commercials!

@xsgt_silverx

4 ай бұрын

@@clabretro then again - why does someone want to watch commercials, and even to think about the pain it would add to add them in between - but it would be surely suit for a fun video. Shame that the blonder tongues only can supply one channel - Imagine having 12 per unit. CRHL News !! 🤣

Very interesting! Then again, I find every rackmounted device interesting, no matter what it does ;)

@clabretro

4 ай бұрын

I feel exactly the same way haha

@Dave102693

4 ай бұрын

Same here

This is super cool. I used to have a single channel unit that I used to broadcast VGA output from a laptop displaying a multiview from Unifi Video to see security feeds all over the house. I ended up scrapping it when Protect came out with the viewport devices. Might be worth revisiting the same idea with a Unifi Viewport and an HDTV QAM modulator so the feeds would actually be bearable on large screens

@clabretro

4 ай бұрын

Ha I did something similar, I had a raspberry pi listening to the UNVR RTSP feed and outputting it over HDMI.

analog video is a technical achievement above and beyond the medium latency high bitrate digital video standards also that modulator didn't lose it's black coating- it never had one. that was an option. you could also get colors of you asked, i have a yellow one with a red CNN logo. i'll test this on my proxmox server later, though i think i'll be passing a discrete GPU through later and using a cheap hdmi2av converter to make use of the GPU's onboard audio. this way i don't have to bother with a desktop and the audio on my server root

@clabretro

4 ай бұрын

That's very fascinating about the coatings and colors, cool you have a CNN one! Yeah the goal would be off of root and getting a VM doing the work, just haven't dove into pass through yet. Definitely the way to go in my opinion.

Solidly in the category of "more trouble than it's worth but it's cool"

I never thought I would see the name Blonder Tongue again, let alone on a youtube video. oh how the world has changed

I have no idea why I'm watching but I don't think it's possible to stop watching

I wanted to do this a year ago and there was no real tutorial on this. Thank you!

I love this frame for viewing content. Live streams could be each their own channels too. Then any stream vods can use the DVR experience

I would love to do this with the open source recreation of the classic weather channel. Would be awesome to have local weather for just my house.

@clabretro

3 ай бұрын

probnotstech has a great recreation of a Canadian weather channel youtube.com/@probnotstech?si=kpO3a0oHrU48Ealy

Such a cool idea and setup! It's strangely timely that a couple weeks ago I saw a dual-CRT rack mount display at my lab at work (aerospace), and thought "man that'd be cool to have for no reason at all" lol. Now I have a reason to keep an eye out. Awesome work!

@clabretro

4 ай бұрын

ha nice! and thank you!

What a delightful random find from KZread browsing. i have one of those Blonder Tongues for modulating old video game systems.

I absolutely love this type of content, taking things that were made to perform a certain task and modifying them to do those tasks in even cooler ways that the creators never even intended. I Too have a home lab setup but on a bit of a smaller scale. I use a dell precision workstation tower inside of a 15U wall mounted network cabinet. I just run unRaid and plex with its supporting services of course but with a larger budget id love to get my hands on equipment like this. That Wohler lcd rack (albeit maybe a newer one with HDMI) would be absolutely perfect for at a glace status of various docker containers or network services.

@clabretro

4 ай бұрын

very nice! yeah an LCD rack would be sweet for monitoring stuff like that too

I'm thinking you get a Blonder Tongue MIRC-12 or HE-4 chassis, get the MICM or whatever type modular modulators (doesn't that sound silly?), then screw the Raspberry Pis to some mounting plates that make 'em MICM-shaped so they can slot right in next to their modulators. Neat and tidy!

@clabretro

3 ай бұрын

oooh yeah that'd be sweet

I have done a lot of this over the last 10 years, I also use VLC setup files with main difference is I use WinTV cards. I get off eBay at the right price the PVR-350, as they will output a analog video signal without the need for VGA, HDMI converters. If you are interested I can send the setup files, plus more information on the automation software.

@clabretro

4 ай бұрын

Very interesting about the PVR-350. Yeah always interested to learn more, you can shoot me a message at the email in the channel's about page if you're up for it.

I've always wanted to do this when i was a kid, and now that i got a lab~ thanks for sharing!

This is so nostalgic. I love it. Now I wanna do this except I don't have cable in my house.

I am learning RF engineering now and a lot of times we use transformers to impedance match as well as give voltage gain, the reason it worked better with one rectifier over the other could be because it had a better impedance match, but yeah you should be weary because a poor match can introduce a lot of loss.

Always expecting interesting stuff from you dude! Can't wait to see what you come up with next! Great job.

@LeeZhiWei8219

4 ай бұрын

Oh what? Your wife plays the N64? Which games does she play? Haha.

@clabretro

4 ай бұрын

Ocarina of Time is her favorite, but she's quite the beast at Mario 64 haha

@LeeZhiWei8219

4 ай бұрын

@@clabretro nice!

This brought me so much joy and I learned a lot. Good job.

I watched a video on this a while ago. It wasn't your video, but thanks to me watching that, youtube suggested this video, which lead to me discovering your excellent channel. I am impressed by this. I probably wouldn't do it myself, as while I love watching old shows,I don't have any CRT TVs to play them on, and I consider adverts a necessary evil rather than anything good, so I don't have a stock of old ones, and no real interest in finding them. In short , I am interested in the old shows, but not in recreating my experiences watching them when I was a kid. Hell, I recently re-watched The Six Million Dollar Man, and then The Bionic Woman. If I was interested in re-creating my original experience watching them, I'd have watched them mostly on a 5 inch B&W TV on top of our fridge, and partly on a 21 inch TV in the living room.. Still, an excellent video on the project, and I also like the other home lab videos you do. You even inspired me to set up my own "home lab", but as I don't have a lot of room, my "home lab" is a mini PC with 2 terabytes of SSD running Proxmox and a series of VMs.

UI on homelab cable is not a problem, please dont update and release as is. I love it and it works dont need any fancy reactive bs (edit: nvm i see you already released it)

you should add a emergency alert system endec and a charecter generator. that way you could get a alert for a tornado or flash flood, the sage eas endec and sage digital endec both require additional equipment for said alerts but some others can do that. the tft eas 911 also cant.

Watching this brought me back to my days of building Crestron units in my factory job. I was wondering out loud if those would work for this too (they probably would), but then I saw the price on 'em. Great content :)

@clabretro

4 ай бұрын

Ha nice! And thank you!

Been highly thinking about doing something like this in my next home. But, instead of using analog channel stations I wanted to use Digital converters to access digital stations so I can at least get 1080P . Great Video BTW

@clabretro

4 ай бұрын

thanks!

Nice video, I'm also thinking of building my own homelab cable - but in PAL format. I was a kid when the cable in my city moved to digital but I had many good memories with it. Btw, another little suggestion - you can add a timetable mode that plays the given video files at specified times, just like how the real TV stations work.😉

I was hoping that you would have some sort of in-house cable network, but alas it's just RF modulators outputting video to one or two outputs. My dad worked in Cable TV for 45 years. When I told him you were using Blonder Tongue equipment he laughed and said it was all junk. They would buy smaller cable companies that had bought all Blonder Tongue equipment and just completely trash their head-in. Higher quality stuff would be resold to South America, so good luck finding anything better.

@clabretro

4 ай бұрын

Haha I've been hearing the Blonder Tongues were basically bottom tier. And I'm inclined to believe it, I was pretty underwhelmed once I looked inside the units.

That little thing the wire is passing out of supply is pass trough capacitor. Totally normal to see in compartmentalized RF equipment, there would be a ton of these on old equipment. Recap that stuff anyway since it is older than most viewers. 470 Ohm or even 1k is good for indication at 12V, don't need to burn your eyes. I already see the comment about output power of this kind of equipment, so won't double it. Well, i didn't knew that "compartmentalized" word existed, but spellcheck helped. Thanks for nice videos. Best Regards

Very cool! This channel is quickly becoming one of my new favorites, keep it up :)

@clabretro

4 ай бұрын

thank you!

Normies: I built a home network. You: I did the same thing. With enterprise gear. And then I got bored and built a home cable tv network.

@clabretro

4 ай бұрын

😂

That is a fun idea for old equipment. I recycle a lot of older stuff like that if it isn't worth the trouble of selling. Also cable management arms are another nice thing to have with your rails. 😜

@clabretro

4 ай бұрын

oh yeah the cable situation is a disaster lol

Oh my gosh, this is so cool. I'm doing something very similar with a bunch of small Sony LCD rack monitors to make a video wall.

@clabretro

4 ай бұрын

nice!

A much more flexible system is using a SEMv8 ingesting MPEG 2 streams and you can mix and realign them using Terayon DM6400 units. I did this for my job for a couple of years. You can use ANY converter that dumps out MPEG 2 compliant streams and those are all over ebay. That was done at one of our schools to kill of a T channel in use that was super noisy.

@clabretro

4 ай бұрын

oh yeah that'd be cool

I've got 5 4Ch HD HDMI RF modulator and I am about to build a similar thing. Going to have central pay TV boxes and Apple TV boxes and distribute around the home along with our CCTV iso cameras

Awesome video i love when you work on the homelab cable project that you have been doing! Its such a good use of the houses coax I was thinking about doing this now that fiber is run to my house, keep up the great work!!

@clabretro

4 ай бұрын

Thanks!

This is like watching a circa 2000 tech video but it’s happening in the present day, I love it! Dealt with a lot on R720s back in the day 😊.

@clabretro

4 ай бұрын

glad you enjoyed it!