General Stuff(tm)

[stephen_usher]

The wood has arrived for the model railway baseboard framing. I'm definitely over engineering this.

[stephen_usher]

That's it for the night. Two of the eight main baseboards built.

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[stephen_usher]

Well, after half a week of working on the baseboards they're complete.

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The bridge section nearest the door is removable allowing unfettered access to the inside section.

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I promised myself that by the end of Friday evening I'd have trains running. Well, I did but I cheated using set-track curves and making a loop on one side.


The next task is to clear up and remove everything from the top surface and then lay 2mm thick cork over the whole surface. This will act as sound deadening. Once this has been done I can start laying the track properly.

[stephen_usher]

In other news:

I replaced the motherboard power connector and Molex KK crimp terminal connectors on the Apricot F1. After over two years it has proper grounding from the power supply. I think the original crimp terminals in the Molex KK plug had corroded so much that the copper wasn't really making good contact with the steel. I'd tried flowing solder over the surfaces of the connectors but that hadn't made any difference.

All good now though.

[stephen_usher]

Rescued three monitors from the work scrap pile today...

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[exxos]

Still got my Sony Trinitron 14" portable in the loft somewhere I think. Don't think it has been turned on for 20+ years now.

[stephen_usher]

The broadcast monitor (PVM-1442QM) does everything it seems.

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Though it's a pity that someone has shortened the mains cable down to about 30cm. It's a right pain actually.

[stephen_usher]

Still got my Sony Trinitron 14" portable in the loft somewhere I think. Don't think it has been turned on for 20+ years now.

[stephen_usher]

So, what have I been doing these last couple of weeks?

Took a load of computers and the Jaguar to a games event last weekend. Other than this I've been trying to fix TVs and started today to lay the track for my model railway, at last.

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On the TV front, managed to get the tiny JVC monitor to work with the help of my bench power supply. It seems that the internal PSU didn't have the grunt to power up the capacitors the first time it was turned on in probably 30 years so the PSU cut out.

I think I need to recap the monitor though as it has some display issues and the caps are over 40 years old. (The manufacture date for the top plastic cover is Feb '81.) But it mostly works.

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The other display I'm working on is a TV I got off eBay a couple of months ago, which is the same model as the one I used to use with my ZX81 and Spectrum:

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It has "issues". I had to rebuild the aerial board as someone had removed the socket and lashed up a lead to where the loop aerial should be. Secondly, the picture wobbles a lot. Soon after I got it the display went off, so I took it to a TV repair bloke who charged me £80 and spent 6 weeks "working" upon it. Looks like he merely reflowed the HT coil but didn't fix anything else.

Anyway, time for a recap. I had stock of enough the replace the caps in the horizontal scan circuitry but this hasn't fixed the fault, but it has shown that the caps definitely need changing after 50 years. I took one of the 0.47uF 50V caps out to test and found that it was now about 0.8uF. This is, along with a twin, are used in the demodulation circuit so could be causing the problem. Anyway, I didn't have replacements so I've ordered a set of caps from RS which should arrive on Wednesday. I found (and bought) a schematic for the TV on-line but it's a poor scan and many of the stated capacitor values don't match what's in the telly.

[PhilC]

@stephen_usher cool that that small tv is actually colour and that it still works after all those years.