Yo Tom, I must have missed something. When did we start cooling 813's with a smoke stack?
Terry
Hola Terry,
I only know of one guy who's doing it with a chimney. I'm sure there's others. He claims to be getting 800W!! carrier out of a single 813 ...blown.
ANY glass tube will increase it's power diss rating by moving air by it. Take the 833A. The Eimac specs rate it at 350W no air, but 450W with air flow. I plan to cool my 833A's.
As for the 813, the fil is 50W and the plate structure looks almost as big as a 3-500Z. But they are rated at only 125W. I'm cornvinced with good air/chimney that figure can be increased to 250W. Esp cuz of the capacity of the fil to deliver power.
I ran my old 813's w/o air and found they got pretty hot as modulators. But this time with air they will run cool at the same power level and the seals will smile.
Either way is FB, but I just thought it wud be unique to have a silent air flow on a single 813 final to see how much power I could safely run it. 3200VDC will be the goal, plate modulated. I'll post some pics when it's running.
T