[Buzz]

Hi.. I have just finished my first attempt at restoring a Philco PT92. After replacing the capacitors, it fired up (used my newly built dim bulb tester). It picks up stations, but i noticed the 50L6 tube gets very hot. I measured it at 172 degrees. The other tubes are warm, but not too hot to touch. I had an old spare I put in, and it gets hot to. (same temp)
So, what is the normal temp of this tube. By the way , I played the radio over 2 hours, and everything else seemed OK.
Any comments or ideas on this,
thanks, buzz