Originally Posted by SP Wild
Feeling that now. The tubes need checking on my amp and a check for bias drift is due. Not playing up in winter, now, but before winter when it was warmer it squeeks, before it never used to do that. My tube hybride amp is now also doing the same. Its been several years of headach free operation, untill now. At least, unlike a solid state amp, when a tube amp starts farting around you know new tubes will fix it.
In the 60s no housewives had tube testers at home so they would take their tubes from the TV and check them when they purchased groceries at the market. If the first set tested good on the machine they would then bring another handful to the market the next day. The odds were after checking 10 tubes, the housewives usually could find the bad tube.
This was just normal tube tv life in the 1960s in America. Women did not work outside of the home and the husband did not have time during the week to go to the market to test tubes. The interesting part of this was the machine that tested the tubes also had a stock of tubes below for sale to replace the bad one. You would take your new tube and put it in the cart and pay during check-out just like buying a light bulb. The remainder tubes would be put into a small paper bag and put in the gals purse. When they got home the moment of truth was to put all the tubes back where they went and turn on the tv. If there was still issues that's when the repair man was called.
TVs had a plethora of knobs and buttons to adjust stuff and at the risk of having to drive back to the market these amazing housewives got really good at keeping track of putting back the taken out tubes and adjusting the 5 to 10 levels you needed to get a great picture. All this before the man of the house came home for his dinner waiting, drink and tv in perfect running condition.
The folks who made the tubes and were kind enough to let those housewives use that exotic and giant tube testing machine and subsequently found out that if they put more electricity into the tube testing process they could burn out the tubes faster and sell more tubes. And remember the only way was to basically check every tube in the TV. Some housewives actually got good and learned which tubes did which to the picture or sound of the unit.