The Drive on a class C circuit is set to swing the conduction of the tube from cutoff to saturation with in a RF cycle. In this type of service, the tube is cut off for about 290 degrees and at saturation for about 70 degrees of the input RF cycle. I use the word "ABOUT" because obviously there is some time that it is in transit and this is where the plate dissipation is greatest. Once the bias and grid current have been achieved by the grid leak due to the drive then increasing the drive has very little effect on the output. Decreasing the drive below the point where output begins to drop will result in the service not being class C any longer. That is to say that the ratios of conduction angle for saturation and cutoff are no longer proper for the class of service and efficiency will suffer. I'm sure since the 2E26 does not have the space charge that the 6146 has, then it is designed to run at lower bias voltage and RF drive. Whether you run it a 2ma or 3ma will have very little effect on the output or the efficiency. If you're going to pull the loading back to draw less plate current (a function of the tank loading circuit) when the plate tuning is dipped, then that could be done with either tube.
John, WA5BXO -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Schmidling Sent: Monday, November 13, 2006 10:38 PM To: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Class C finals John Coleman ARS WA5BXO wrote: > So it would seem that if you replace the 6146 with a 2E26 then in > order to get the proper operating parameter for the 2E26 one would need to > reduce the loading. So why not just reduce the loading on the 6146? The suggestion was to reduce the drive on the 2E26 and load it to where it is comfortable which suposedly would be at 15w. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com ______________________________________________________________ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net ______________________________________________________________ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
