Sony Betamax SL-C9 video recorders. Part 2.

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video99.co.uk

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@thebreretons 4 ай бұрын

In my experience the trick head on the C9 was always the first to wear out, I worked on many of these and supplied reconditioned machines to the National Sound Archives as PCM recorders. The original production heads had pale blue and white leads, identical replacements (to begin with) from Sony were supplied in polystyrene frame within a white cardboard box and were of far better quality than later Sony replacements which came in a black plastic clam shell box.

@1lennetje 5 ай бұрын

Another very interesting video. Thank you for that. I have a number of PCM processors here, including the PCM-501, the 601, the 701 and the F1. When I want to make a digital copy via the S/PDIF output of the 601, I switch the equipment as follows: Video recorder SL-C9 or SL-F1 - PCM 501 - via copy out to play in of the PCM 601 and then digitally out to an (Edirol) hard disk recorder. The advantage of placing 2 PCMs in a row is that the 601 receives a stable video signal, reconstructed by the 501, which makes error-free conversion to S/PDIF possible. My experience with the 501s is that they exhibit malfunctions when they have not been used for a while. This is also reflected in your video. I've never had that with my 601s, 701s and F1s, but as mentioned, the malfunction in your 501 looks familiar to me. You could leave the 501 in question on continuously for a few days, and the problem will often resolve itself.

@video99couk 4 ай бұрын

I thought I was the only person to have the whole set of these decoders.

@1lennetje 4 ай бұрын

@@video99couk You and me :)

@janosnagyj.9540 5 ай бұрын

Wow, what a rollercoaster ride 😅 I'm always doing the same way you did here, after unsuccesful swap I check back if at least I did not made something worse, and man how many times I became crazy, what would have happened that the machine is not working anymore at all 😅🤣🤣 And it seems to me also that you are playing with pretty much the same toys there as I do here, as I have a 701ES as main PCM processor and have a "backup" 501 as well 😅 I love the 701 as you pointed out for its sound and the gorgeous display! I made some modifications to it though: I mounted every dissipating element in the PS to the heatsink on the rear, so the internal temperature remains normal, not 75-80 degrees as before (celsius, of course... 🤓) and I changed the trimpots to multiturn ones as with the originals it was really difficult to properly calibrate e.g. the 0 offset. Is it difficult to build that s-pdif output for it? Cheers!

@video99couk 5 ай бұрын

There was a "Whistlewood" S/PDIF mod for digital out, but they are very hard to find now, and even when you get one they can be quite tricky to get working reliably. I've had to fiddle with the PLL chip to remove jitter, more than once.

@Petertronic 5 ай бұрын

I wonder if they used a less durable (cheaper) material for the A' head, which wears out faster than the primary heads? I'm sure I've never been able to see the signal directly off the heads on a 'scope. Maybe with a fancy active probe you could.

@tonygroenewoud-powell53 5 ай бұрын

I haven't gotten to the end yet, but my immediate thought was perhaps it was because Crossroads was ATV and not A-TV? ;-)

@stickytapenrust6869 5 ай бұрын

I think this is Crossroads from the 80s, so Central TV era.

@cernyjana6493 4 ай бұрын

Do I remember correctly, that the C9 is unique since it is the only VCR ever produced for consumers with a HF-Modulator that is capable of transmitting stereo sound over HF?

@video99couk 4 ай бұрын

That might be possible in some parts of Europe, but not the UK. The NICAM stereo standard wasn't introduced until well after the C9's lifetime.

@crashbandicoot4everr Ай бұрын

Only the ES and ECS variants of the C9 can do that. The E, UB, F and AS variants only have a mono tuner and RF modulator.

@fabrizioimperiale 5 ай бұрын

It's always scary for me to remove the upper part of the heads. When I have a spare, I prefer to change the entire drum block

@video99couk 5 ай бұрын

I know what you mean. With all the care in the world, I've smashed one or two head sets over the years, once a brand new set of very rare V2000 heads.

@crashbandicoot4everr 5 ай бұрын

@@video99couk I did smash a VTC 9350 head chip once. I really do hate myself sometimes...

@zhaohaigaogu7821 5 ай бұрын

🏆👍

@vhssnippets1799 5 ай бұрын

I don't know how practical this would be, but if you swapped the connections from the A' and B heads, you could then look on the scope to see what the signal level is like from the A' head during 'normal' playback. This might help rule out the fault being due to a faulty channel B amplifier in the IC701 (pin 1).

@video99couk 5 ай бұрын

Yes, I think that could work.

@janosnagyj.9540 5 ай бұрын

It's a really interesting fault, and I'd say it very unlikely that both of the boards he tried would have the same channel error in that IC... except, if it was a known manufacturing defect back than! Like many Sanyo ICs in the past, they were just prone to get faulty. The problem is that he pretty much sorted out any possible reason already... he even checked the rotary xformer primay and secondary as well, as I had issue with those several times - ok, those were Philips made VHS drums, but still 🤣 it might happen. At this point, I would have really no idea what to try... I don't know that swap between A' and B would give any sensible result, as the geometrical difference might cause out-of-track signal reading even if everything is fine... it's still a try, if there's nothing better to do, it might worth it...

@frankowalker4662 5 ай бұрын

You could try swapping the A and A- head wires to see if you still get playback picture. (?) Also, it's a bit worrying that the head disc is stuck. 🤔

@crashbandicoot4everr 5 ай бұрын

The service manual mentions that if the head disc is stuck, you can put the screws into the unused holes and then pull the head disc by grabbing on those screws.

@video99couk 5 ай бұрын

Will do, if I come to swap the heads again.