Have you ever been clumsy while installing or removing power tubes and ended up breaking the guide “key” off?  If you’ve experienced this bad luck before, don’t worry, it happens…  The good news is that often this tube can still be used safely.  As long as the glass bottle has not suffered any damage the tube will still function normally.  But it takes careful attention to properly install a power tube in this condition.  Check out our How-To for step by step instructions.