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<blockquote data-quote="Llew" data-source="post: 766495" data-attributes="member: 175007">I've got scores of valves from servicing radios, TVs and DIY projects. Most ambitious project was a colour TV. In the early 70's I constructed one from a design in Practical Television using a PL503/PY500/tripler line output stage, semiconductors for the rest of the circuitry. All circuit boards had to be drilled out for the components, a tedious task indeed. I never managed to have a decent picture, as it was impossible to adjust properly for static convergence due no doubt to anomalies in the original design of the convergence stage. In fact, there were many months of errata/modifications for most of the circuitry to follow in the magazine, so I considered that project a noble failure.I then made another TV using kit from Forgestone. They were better designed, and I could use the existing Mullard CRT and home-made cabinet. This TV served well for a year or so until the PY500 in the line output stage started glowing purple and needed to be replaced regularly. In the end the TV was consigned to the shack and raided for spare parts, where the CRT, LOPT etc. came in handy for repairing other TVs.</blockquote>

[QUOTE="Llew, post: 766495, member: 175007"] I've got scores of valves from servicing radios, TVs and DIY projects. Most ambitious project was a colour TV. In the early 70's I constructed one from a design in Practical Television using a PL503/PY500/tripler line output stage, semiconductors for the rest of the circuitry. All circuit boards had to be drilled out for the components, a tedious task indeed. I never managed to have a decent picture, as it was impossible to adjust properly for static convergence due no doubt to anomalies in the original design of the convergence stage. In fact, there were many months of errata/modifications for most of the circuitry to follow in the magazine, so I considered that project a noble failure. I then made another TV using kit from Forgestone. They were better designed, and I could use the existing Mullard CRT and home-made cabinet. This TV served well for a year or so until the PY500 in the line output stage started glowing purple and needed to be replaced regularly. In the end the TV was consigned to the shack and raided for spare parts, where the CRT, LOPT etc. came in handy for repairing other TVs. [/QUOTE]

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