Ferguson 3V20 Vintage Video Camera Repair

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This camera has a vertical linearity problem whereby the scan is compressed towards the bottom giving a stretched image at the bottom of the frame. You can see also at the top of the picture that the scan is not straight. This doesn't affect the colour because the camera uses a step energy vidicon tube with a vertical stripe filter meaning it only requires the horizontal scan to be correct for proper colour, however, there is a green cast to the picture. I manage to fix the deflection fault (althought there is still a small amount geometric distortion), replace some other failing components and then go through the full setup procedure to restore good picture and colour.

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4 окт 2024

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Комментарии : 13

@jackmilne9764 11 месяцев назад

Top video same as my Dad's watched it all the way through sadly too complex for me, you know your stuff. Great end result

@bruno9663 11 месяцев назад

Godly stuff

@ambientmoder 9 месяцев назад

Do i need to understand those electrical diagrams and have that equipment in order to just replace the capacitors?

@nowt1002 9 месяцев назад

Not really, if you're just going to replace caps you just need a soldering iron. Make sure you put them in the right way round.

@KylesDigitalLab 5 месяцев назад

When pointing the camera at a white wall for doing adjustments such as beam current, do I have to remove the softboxes from my two Neewer NL660 studio lights? Or will that provide enough light. I have another 60W Vivitar light that doesn't have a softbox.

@nowt1002 5 месяцев назад

Hard to say, you'll just have to try it and see I think. Most adjustments require you to set the iris so that the output waveform is a particular peak to peak voltage so if you can get that voltage without having to open the iris fully then it should be enough. With the beam current you have to open the iris fully and the light is sufficient if you can set the beam current for the correct peak to peak voltage with the waveform (it will be the output of the preamp i think) being hard clipped (flat on the top) then it's enough. For some adjustments such as ones relating to the white balance you need light of the right colour temperature.

@KylesDigitalLab 5 месяцев назад

@@nowt1002 It says to vary the iris just before beam saturation. Does that mean I just set the iris to exactly the point where if I open it up any more I'll get the green? Is that what they call beam saturation?

@nowt1002 5 месяцев назад

No you need to set the iris so that you have beam saturation and then adjust the pot so that the saturation occurs at the specified voltage. Beam saturation is where the waveform clips, ie its flattened off at the top. If you open the iris and then adjust the beam current you'll see the flat top of the waveform move up and down, you need to set it for 0.55v peak to peak according to the pal service manual, I imagine the ntsc one will be the same but check. You usually have the iris fully open for this adjustment.

@KylesDigitalLab 5 месяцев назад

@@nowt1002 So I went to do the adjustment today and it actually appears the beam current problem is gone - when I point the camera at bright lights even with the iris open all the way on standard gain there is no green. I guess it has to do with the fact my GR-C1 hasn't been powered on for at least 30 years. Could be the tube itself warming up or the capacitors. But anyways it works and I've got a working battery now so I'm all ready to upload some footage to RU-vid - haven't seen any GR-C1 footage that has been deinterlaced and upscaled to HD.

@nowt1002 5 месяцев назад

That's good. Probably the tube I would think. You get the same thing with picture tubes that haven't been used for a long time but it manifests as a dim picture. Hopefully it will be ok now.

@KylesDigitalLab 9 месяцев назад

Do you know any adjustments to possibly fix a tube camera that has a very dark picture? Assuming the tube is not worn. I own two Canon VM-E1 8mm Saticon camcorders, and one has a working tape transport but the picture is very dark and it only really works outside. Like I'd have all the lights on in a room indoors and it would just be black expect the light blub itself. I have the schematics but not an adjustment manual. Looking at the boards it looks like there's a power board that generates the high voltage for the tube, and then a deflection board. There is a variable resistor on the deflection board marked "BEAM", I'm wondering adjusting the beam current might make a difference?

@nowt1002 9 месяцев назад

Would you be able to link or email me the schematics please? I wouldn't touch the beam current at the minute if you don't know what it's meant to be set to. I would say the fault is more likely to be in the luminance process circuit. There will be some circuit that clamps the signal to a fixed dc level, that's where I would be looking after confirming that supply voltages are OK. If you can send me the schematics I can try and find the circuit to look at.

@KylesDigitalLab 9 месяцев назад

@@nowt1002 I just emailed you them