[EMAIL PROTECTED] made an utterance to the drakelist gang ---------------------------------------------------------------------- On Wed, 30 Nov 2005, Garey Barrell wrote:
> I ran three 4 Lines on autostart RTTY. They ran 24/7, and often made > transmissions in excess of 30 minutes, AT FULL POWER. In this service, > the finals lasted a little over two years, typically, with "end of life" > defined as 100W output on 20M. This piqued my curiosity again - Let's say you're running your T-4XB at full power for 30 minutes at a time at 300mA and the plate is perfectly dipped. All is good. But if the plate isn't dipped at 300mA and would be at 240mA if dipped properly there would be 60mA of current wasted as heat running at 300mA. But it's still 300mA, whether resonant and dipped at 300mA or splattering at 300mA - the thing i'm wondering is if the tubes are suffering more at 300mA undipped or if the life expectancy the same as 300mA dipped perfectly, being paced at a rate of current (heat) travelling through the metal. And I suppose the other question is "what is a plate dip" anyway - can I think of it as if the tank circuit is sucking the power out of the tube or is it best to think of the tank circuit as a valve that passes the power when at resonance, and the current increases as the RF power output is "backed up" and can't get out? Sorry for the rudimentary questions but I can't find this online anywhere and don't have an old ARRL handbook that explains it. thanks -- 73 Jason N1SU http://n1su.com/ ---------------------------------------------------------------------- Submissions: [email protected] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
