Betamax s-video mod for SL-HF900?

[aramkolt]

I know the idea has been thrown around a lot about S-Video modding various VCRs for S-Video output, but Betamax seems to be especially in need of this since most machines didn't have S-Video output aside from the EDV models which are pretty scarce.

I want to try "S-Video Output Modding" an SL-HF900 as they seem to be relatively common and mechanically reliable from what I've read.

Where I need help is determining where I'd need to actually tap luma and chroma for the mod (and if any other components need to be added).

I've attached a truncated service manual that only shows information that should pertain to an S-Video mod. I can see several candidates of where you'd tap as the service manual does show waveforms and peak to peak voltages at different test points which is nice.

I have a few non-working SL-HF900's on their way to me and assuming I can get at least one of them working, I'll try the different S-Video tap point suggestions presented and report back.

[latreche34]

If anything it would be the Vl-10 (Y/C SIGNAL PROCESSING) board, The hard part is syncing the C to Y, You can try to connect a stripped S-Video cable to the Y and C points and see how they look sync and level wise, Otherwise you would have to get the Y from the composite out like the uMatic mod, not perfect but better than composite only.

[aramkolt]

Yeah, the only boards in the attached truncated service manual document are about the VI-10 Y/C board, but I'm not sure where to actually tap them on that board since there are several stages of processing. Much of the board is used for Y and C record separation (such as the comb areas) wereas what we need is the "Playback" or "PB" Chroma and Luma at levels that are appropriate for S-Video output. Ideally they'd be tapped in such a way that it wouldn't kill the usual composite output as well, not sure what considerations are needed there, so still looking for suggestions where specifically to tap for those.

[latreche34]

I would check them all if you have the scope or a voltmeter in AC mode, but the scope is better since it gives you the frequency reading in addition to voltage, Anything around 0.7V should be worth hooking up to a video monitor.

[timtape]

Quote:

Originally Posted by aramkolt

I want to try "S-Video Output Modding" an SL-HF900...

It would have been so much easier for Sony to incorporate it at the design stage. Question is why with the HF900's horizontal resolution 20% better than standard Betamax, and at that stage the top of the Sony Betamax picture quality range, Sony retained composite output, and only provided S-Video connectivity on later higher def formats such as Hi8, SVHS, Betamax ED.

I've read JVC SVHS deck Owners Manuals which state that to obtain full playback resolution of SVHS recordings, the S-Video output socket should be used. No surprise there. But today some people would be surprised JVC didnt add:
"...and as a bonus the S-Video connection will improve playback resolution of your standard VHS recordings."

I still wonder why that clause is not there. If JVC knew S-Video would also improve VHS playback why didnt they mention it, even brag about it?

Any ideas?

[lordsmurf]

Quote:

Originally Posted by timtape

I still wonder why that clause is not there. If JVC knew S-Video would also improve VHS playback why didnt they mention it, even brag about it?
Any ideas?

I think it came down to marketing choices.

S-VHS was the "rich consumer" format. I forget if it's Married With Children season 1 or 2, but the neighbor Steve bought one right after it came out. And yet, I don't recall any actual JVC product placement, just the mention of Super VHS, and how it's better. (I need to watch it again. Great show.)

Victor Company of Japan (JVC) was, well, Japanese. In the 80s, especially for electronics, Japanese companies still heavily relied on honor, presenting the companies more for reliability (product longevity), trustworthiness, customer service, and not so much product features. A lot of Asian companies, still, to this day, have a deep death grip on what their USA arms are allowed to do (Sony, Nintendo, etc), to preserve this image.

And yet, ironically (and only to us, not them), the Japanese have also always been more into zany Animaniacs-style advertising, which is sooner to show that a VCR can double as a sushi cutting board, with a Pikachu popping out of it, rather than what the device actually does.

In the 80s, the Japanese economy was booming. The '90-91 economic crash in Japan caused a lot of companies to reel in their expenses, and cost-cutting has an dire effect on marketing. (I actually wrote a grad thesis on how economic change harms marketing, back in the 90s.)

So, lots of factors at play here, at that exact time in history, in that exact location.

In hindsight, yes, advertising s-video should have been a no-brainer.

On the other hand, you had companies like Canopus, that were marketing whores, on the verge of just lying to customers about what their products could do. Although I fault that mostly on Canopus USA, and their use of halfwit copywriters (who didn't understand concepts like "audio lock"), not the Japan home office. Canopus marketing felt entirely telephone gamed.

[latreche34]

Quote:

Originally Posted by timtape

I've read JVC SVHS deck Owners Manuals which state that to obtain full playback resolution of SVHS recordings, the S-Video output socket should be used. No surprise there. But today some people would be surprised JVC didnt add:
"...and as a bonus the S-Video connection will improve playback resolution of your standard VHS recordings."

That's not actually what S-Video is for, Super Beta and S-VHS increased only the luma bandwidth of the analog video which you can take advantage of via composite without any problems, At that time when Beta was popular S-Video was a new concept, TV sets did not have it, So Sony didn't bother acquiring the licenses when they knew no one would take advantage of it.

S-Video real purpose is to help reducing cross-talk between luma and chroma, Especially with S-VHS recordings where luma is taking most of the bandwidth, So the need to separate the two for better chroma quality was necessary, hence the name separate video, And as LS said it was also for marketing purposes to make S-VHS a better choice over Super Beta.

When S-Video became known and found its way into TV sets and camcorders, Sony did add it to one of their high end Super Beta machines and the ED beta models, but at that time the writing was already on the wall for Beta, it was just grasping its last breaths.

[timtape]

Quote:

Originally Posted by latreche34

...S-Video real purpose is to help reducing cross-talk between luma and chroma, Especially with S-VHS recordings where luma is taking most of the bandwidth, So the need to separate the two for better chroma quality was necessary, hence the name separate video,

So the improvement in playing VHS recordings on their SVHS decks via S-Video was less obvious but still there? If so I wonder why JVC mention that in the Owner's Manuals.

[latreche34]

Usually user manuals are not written by engineers, They use a language that the average person can understand without going too much into the technical details, "Full playback resolution" in itself doesn't mean anything, but it could technically mean crisp chroma with no noise.

[timtape]

Quote:

Originally Posted by latreche34

Usually user manuals are not written by engineers, They use a language that the average person can understand without going too much into the technical details...

True, so they might have said "a better picture" or "better color"...

But nothing. They made no mention of any improvement in VHS playback. And didnt JVC develop SVHS? How could they have missed that golden opportunity to tell people of that side benefit? What were they thinking?

[BW37]

In almost 33 years working for a large corporation, I seldom understood the minds of the people in marketing. One thing I recall is that they’re always trying to “segment the market” to justify the premium pricing for “upscale” products. That might be a reason they don’t mention better VHS playback in S-VHS decks. Also, gotta keep pushing those more expensive S-VHS tapes of course!

BW