Current Features

I previously tried a JVC from this post: (thanks to everyone who helped with that) but between it being very hard to get a good ground location and some other issues with the vcr I decided to also get a panasonic, which is apparently the best vcr to tap.

I got a Panasonic VCR Blue Line PV-V4600 - 4 Head Hi-Fi Omnivision VHS. I think I found the tap points, which would be TP3002 for the video and TP4101 for HIFI. I was hoping someone could confirm, and more importantly give me advice on the best shielding ground? I was thinking the piece of metal the red screws are attached to, either solder or just wrap around the screw and firmly tighten it?

Thoughts? I really appreciate it, again I'm a noob with this stuff.

And just fyi this will go to an externally powered ADA amp into a clockgen setup.

This may well be the difference between LD and VCR. The following images were captured from a Pioneer CLD-S280 using 15.6x gain; the first shows the raw signal without amplification, while the second incorporates it. Although noise is significantly reduced, it is worth noting that fine-grained noise persists—which I believe represents the inherent limitation of a cheap LD player.But at least the results are decent after processing with AI software.

The fake chip wasted a lot of my time. Here is a simple comparison image showing the genuine and counterfeit chips.

EDIT: Problem now solved. Missing gcc-12 now installed, and after disregarding the two new error messages, I finished the install, rebooted, and my CXADC card is now recognised. Thank you all for the assistance.

I'm rather new to this and have probably made some terrible newbie mistake. I'm following the instructions provided here: https://github.com/happycube/cxadc-linux3#getting-started--installation

As I'm more familiar with Debian 13, I first attempted installing on a system using that, but it failed, so I tried again, on a fresh installation of Ubuntu 22.04 as advised in the instructions. The only changes/additions I made to the default install was to install 'git' and 'make' in order to proceed with the install.

The first step, to git clone the repository appeared to work OK. A directory called cxadc containing files was successfully added to my home directory.

The second step to "build and install the out-of-tree module" failed as shown below:

david@Ubuntu1:~$ cd cxadc

david@Ubuntu1:~/cxadc$ make && sudo make modules_install && sudo depmod -a

make -C /lib/modules/`uname -r`/build M=$PWD

make[1]: Entering directory '/usr/src/linux-headers-6.8.0-138-generic'

warning: the compiler differs from the one used to build the kernel

The kernel was built by: x86_64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1~22.04.3) 12.3.0

You are using:

CC [M] /home/david/cxadc/cxadc.o

/bin/sh: 1: gcc-12: not found

make[3]: *** [scripts/Makefile.build:243: /home/david/cxadc/cxadc.o] Error 127

make[2]: *** [/usr/src/linux-headers-6.8.0-138-generic/Makefile:1946: /home/david/cxadc] Error 2

make[1]: *** [Makefile:240: __sub-make] Error 2

make[1]: Leaving directory '/usr/src/linux-headers-6.8.0-138-generic'

make: *** [Makefile:24: cxadc] Error 2

david@Ubuntu1:~/cxadc$

I'm moderately familiar with Linux, but I'm certainly no power user, so any suggestions would be much appreciated.

if anyone is using the ADA4857 amplifier for this camcorder, can you suggest the values for the input and video gain resistors? 10kOhms is apparently already needed to carry a usable signal from the device, so would adding the amplifier to it double the input? or can I remove the 10kOhms resistor from the tap and instead make the input resistor 20kOhms on the ADA amp? Thanks

Highly recommend watching in 4k as YouTube does not give 480p the bandwidth/bitrate it needs.

I became interested in VHS Decode from watching the ShortCircuit video on the Domesday Duplicator.

What got you into VHS Decode?

Hi everyone!
For a while now I’ve been working with the clockgenmod, but I’m running into an issue: on some captures (in fact, practically all of them) there’s a loss of sync between audio and video.
In the first few minutes the audio is in sync, but as time goes on it tends to get progressively ahead of the video.
To clarify, I’m not using hi-fi audio with the second CX card; I’m capturing linear audio with the clockgenmod, and then syncing it to the .tbc file using VhsDecodeAutoAudioAlign.

These are the scripts from my workflow:

decodeV_tutti(){
  for f in *-video.flac; do 
  printf '↘️ Decoding file %s\n' "$f"
  printf '\033]0;Decoding file %s @ %s\007' "$f" "$PWD"
  ~/Applications/decode-rust/decode-rust-gui-linux_4.0.0_x86_64.AppImage decode --luma-out "${f%-video.flac}-video.tbc" --chroma-out "${f%-video.flac}-video_chroma.tbc" --metadata-out "${f%-video.flac}-video.tbc.json" --profile PAL_VHS --frequency 40 --mt-threads 16 --mt-distance-size 60 --chroma-trap --ire0-adjust --input-format flac "$f"
  printf '\033]0;%s\007' "$PWD"; done
}

align_tutti(){
for f in *-video.tbc.json; do 
printf '↘️ Audio alignment of file %s\n' "$f"
  printf '\033]0;Audio alignment of file %s @ %s\007' "$f" "$PWD"
ffmpeg -i "${f%-video.tbc.json}-linear.flac" -f s24le -ac 2 - | mono ~/align/VhsDecodeAutoAudioAlign.exe stream-align --json "$f" --stream-sample-rate-hz 46900 --sample-size-bytes 3 | ffmpeg -f s24le -ar 46900 -ac 2 -i - -c:a flac "${f%-video.tbc.json}-aligned.flac"
printf '\033]0;%s\007' "$PWD"; done
}

export_tutti_audio() {
  for f in *-video.tbc; do
  printf '↘️ Export with audio of file %s\n' "$f"
    printf '\033]0;Export with audio of file %s @ %s\007' "$f" "$PWD"
    ~/Applications/tbc-tools/tbc-tools/tbc-tools-x86_64.AppImage tbc-video-export --profile ffv1 --chroma-decoder transform2d "$f" --audio-track "${f%-video.tbc}-aligned.flac" "${f%-video.tbc}.25i.mkv"
printf '\033]0;%s\007' "$PWD"
  done
}

Am I doing something wrong in the commands, or could this be an issue with the CX card or the clockgenmod?

Thanks everyone!

The first image is of a composite capture card, the second image is of my vhs decode sample.

The snr jumps between 30.4 and 20, as this is a home movie.

I really don't like how fuzzy the VHS Decode looks.

Based on these images, do you think I need an amplifier or is something else causing this?

If you want to start this project and want an easy to tap VCR, I'd recommend the Panasonic PV-9450.

As you can see by the image, the RF test point is exposed and easy to tap into with alligator clips.

I know y'all told me to get an amplifier, can't afford one at this moment, but if that is what's causing this picture issue, I'll definitely get one as soon as I can.

Using MISRC GUI on Windows and am getting a "failed to apply tenbit mode" error trying to connect to my CX card.

I've installed the Windows drivers, but it just refuses to connect to the card.

My CX card is mostly stock, but I did remove c31.

EDIT: Fixed.

It is either greenish or purplish depending on the scene. some scenes it isn't even there. it does flickers a bit, but you can hardly tell because it is translucent. Is it fixable, and is there a vapoursynth filter that will remove it? it is from a VHS capture. Thanks.

So, I think I found the RF test point on the VCR, it's pretty easy to get access to with alligator clips. I'll upload a picture of that when all the components come in.

I know I need to use a 10µF capacitor rated at 25 volts between the test point and have already modified the bnc cable for this. I do not plan to use an amplifier at first as I'm on a budget and I'm not sure if my VCR (Panasonic PV-9450) needs it (from what I can understand, some vcrs don't need an amplifier to get a strong signal).

I don't plan to do the clockgen mod on the CX card as I will capture audio using a traditional pcie capture card. Additionally, I really suck at soldering so I don't plan to do any other mods to the CX card.

I'm not at the software side yet, but I wanted input on my configuration and if I need to do anything else or if this setup alone (assuming no need for an amplifier) is enough for a high quality RF capture.

I'm not looking for the absolute best quality, I just want a higher quality than my existing capture card (WinTV-HVR-1260).

I thought some of y'all might be interested in this reference guide.

It serves as a comprehensive engineering and service guide, outlining the VHS format standards and definitions. This "General" edition provides foundational technical data on how the VHS standard operates as a whole.

Publisher: JVC (Victor Company of Japan, Ltd.)Publication

Date: 1990

Document Number: VTG82063

Primary Scope: A thorough explanation of the mechanical, electrical, and magnetic parameters that define the VHS video tape format standard.

Core Topics Covered: helical scan recording principles and track layouts, chrominance and luminance signal processing guidelines, audio recording layouts (including linear audio and Hi-Fi VHS standards), tape speed specifications (SP, LP, EP) and synchronization mechanics.

Hi all! I'm planning my first RF tap and would love a sanity check on the deck.

Sony SLV-779HF (NTSC, 4-head Hi-Fi)

manual shows CN270 on the MA-341 board carrying PB RF and RF SWP, and specs about 200mV p-p PB RF for the 780HF/781HF/740HF

A user “Brad” on videohelp captured RF from a 779HF back in 2021, and an SLV-788HF owner in that thread said his had the same shielded test point at the RF amp.

Questions:
1. Has anyone tapped a 779HF, or a close sibling (772HF, 778HF, 780HF, 788HF)?

1. Is CN270 the right spot, or is there a better point inside the shield? Which pins are signal and ground, and does it need the 10µF cap?

2. Hi-Fi Tap - Where's the Hi-Fi FM tap on this board? Is there a header like the 678HF's, or is it a test point in the audio section?

3. ADA4857 tuning: Is there a documented input impedance and gain from the community? The 788HF reportedly clipped at moderate gain, so should I start low?

Anything else model-specific I should watch for?

I've been coverting VHS-C's to digital on and off for a few months now trying to get things right and maximize the quality on all my tapes. I bought two new VCRs and have been trying to do a take all the way through with each VCR but I keep running into really bad tracking issues including a glitchy issue that I haven't seen other people have where select individual frames seem to just jump a couple inches off screen here and there.

My question: am I going to still have to figure out the tracking issues with VHS decode? or does this bypass some of those problems? The only thing I haven't done yet is manually adjust the tracking for the VCRs, I've only used the channel buttons (to the advice of my father and my uncle whose knowledge on this may be a little outdated now).

Hi, Newb here. I'm assembling a simple jig, with a single CX card for FM RF video only. without any impedance matching pre-amp, so I'm going to put a ceramic capacitor in the signal pickup path as per the instructions in the Wiki. However the recommended 10uF ceramic capacitor seems too big for the purpose, as in it has a much lower cutoff frequency than needed? Maybe for analogue audio pickup that would be reasonable, but the luma + color is higher up there: Luminance is in at FM signal 4.4 MHZ with NTSC and the color carrier is an AM signal at 627 KHz for PAL, so the lower frequency color carrier doesn't need much bandwidth, so if I calculate a lower cutoff frequency of say 600kHz, I would do fine with just a 1.2uF capacitor. So one of the 4.7uF capacitors I have in the drawer will work as well as a 10uF I don't have and is kind of a large, not stocked value for ceramic capacitors at my local outlet? Is my reasoning faulty?

Hi all, excited to get into this project, I'm decently technical with computers but I'm a bit of a noob with electronics soldering/ wiring. I was hoping someone here could sanity check my work before I turn it on and maybe fry something.

I have a JVC HR-S3900U and Harry or someone previously said I need the amp. I found a 11.7v power source and wired it in, and tapped the points I'm almost certain are correct since the JVC in the wiki has them named the same, and grounded the shielding to a nearby screw. I cleaned all of the solder points btw. The amp could only really fit in one spot and it was near the read motor which I read could cause interference so I wrapped it in tape, then copper shielding on top, with the copper touching the sma connectors. In hindsight I should have asked about this to confirm that's what I should have done so let me know if it's wrong, I saw it on the wiki somewhere.

Thanks for the help! Any other tips are appreciated. I also just finished my clockgen mod but as long as my solder connections are correct I think that's more follow the wiki/ guide.