Many thanks to all those who offered input in response to my query about the merits of adding the second tube to the Alpha 77S type amplifier. The thoughts were insightful and the general consensus w
I believe Alpha fires the high voltage at the same time as the filament .. they just delay the ability to drive the tube until the warm up period is complete. As you mentioned the tranny has all the
The fly in the ointment is that the AL-1500 tank L gets mucho hot with one 8877. With two tubes and 2x the I-anode, figure c. 4-times as much tank loss. _ A tetrode with handles is a practical solut
You will need a minimum of 1/4 inch tubing for 20 through 10 meters, and at LEAST plastic, as it will melt. Even the old robust B&W 800 series tank coil assemblies experience plastic coil spacer fai
Amen, Phil. For 24A (2A x Q=12) of circulating current at 10m, 3/8" Cu tubing is not too large. Rich, AG6K, 805-386-3734, www.somis.org / new e-mail adr r@somis.org
Author: peter.chadwick at Zarlink.Com (peter.chadwick@Zarlink.Com)
Date: Thu Jul 31 07:55:50 2003
Rich in the past has also suggested allowing for extra air cooling of the tank: this seems exceedingly sensible. Some really big tx's (80kW) actually blow air down the tubing of the coil, but I don't
_________________________________________________________ Some really, really big amps use water cooled tank coils, I've heard. Distilled, non-conductive water is actually pumped through the hollow t