Plate Dissipation is the energy loss in heat to the plate of a tube. If Ep = 1000V and Ip = 100 ma = then the total plate input power is 100 watts. If the tube is not doing any output but yet drawing the current then the input power is all dissipated in heat = 100 watts. On the other hand if the tube is delivering 60 watts of carrier to a load or antenna, while consuming the 100 watts input, then the tube is dissipating 40 watts in heat = 60% efficiency. Special Class C circuits can reach 90% efficiency.
John, WA5BXO -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Tom Elmore Sent: Thursday, October 07, 2004 11:28 AM To: [email protected] Subject: [AMRadio] Tube Plate Dissipation Ratings Can someone please clarify for me the plate dissipation ratings on vacuum tubes. I am in the process of restoring a Stancor 60N that uses a HK24 tube and the dissipation rating is about 25 watts. Isn't the 25 watt rating Ep*Ip and is this a maximum value that should never be exceeded? I believe this transmitter will put out 30 to 40 watts of carrier and if it were say 60 efficient wouldn't that bump up the plate dissipation to around 65 watts exceeding the dissipation ratings. Thank You Tom Elmore KA1NVZ Anchorage Alaska
