tezza wrote:RonTurner wrote:My favourite is * it wont tune into my modern TV set *
Depending on the machine this can be valid. My ZX-81 for example has real trouble tuning into any modern TV set. Autofind just skips over it, or even if it does find it, it's hard to get a good signal. On older TVs it's not a problem.
The early ZX81s didn't generate a complete RF signal so many newer TVs, even back then, struggled to produce a clear picture. The signal lacked the "back porch" which was a pulse that contains colour information for the TV. Without the "back porch" the TV won't generate the right colours, including black and white. As a result many ZX81s produced a messy grey picture instead of a clean black-on-white. Even with systems that generate a compete signal, the RF modulators often degrade over time and it can be difficult to get a clean or even recognisable picture.
The fact remains that when we buy old hardware we're taking a calculated risk. Many people really are scared of "doing something wrong" and others just don't see that it's worth the effort to properly test what they're selling. I don't think it's deliberate deception in most cases, and you just have to accept the risk and bid accordingly. Sometimes "untested" gear turns out to be fine and you get a bargain