I have built 4 amplifiers using the 4CX-250B-350R tubes in the so called "Super Cathode Driven" mode, tying the control grid to the cathode and grounding the screen grid....This design was in some ol
Tokyo High Power marketed a cathode driven 2 X 4X150/4CX250 amp that had IMD on par with grid driven. The price was high for the power and didnt sell well in the US. The few I worked on were well bui
"Tokyo High Power marketed a cathode driven 2 X 4X150/4CX250 amp that had IMD on par with grid driven. The price was high for the power and didnt sell well in the US. The few I worked on were well bu
I did a "double-take" the first time I had seen one since Tokyo Hy-Power is more commonly known as a SS amp manufacturer. What's really got me excited is the use of adaptive pre-distortion in the ne
Unfortunately there are very few exciters on the market that could complement the technology Paul. For now its still GIGO. For our junior and international readers that is Garbage In Garbage Out, a t
I dont believe there is any way to run a 4CX250 style tube in GG without destruction. Very few tetrodes have the necessary grid dissipation required. A relay driven bandswitching input network is one
The Collins 30S1 is a good example were it is done with a 4CX250B style tube 73 Peter I dont believe there is any way to run a 4CX250 style tube in GG without destruction. Very few tetrodes have the
I seriously doubt that adaptive predistortion is covered by any enforceable patent and it is certainly not limited to digital modulation. Phillips, Marconi and others, used predistortion with analog
Yes, if you mean cathode driven. It has less grid dissipation than a 250. Carl KM1H _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/m
ORIGINAL MESSAGE: REPLY: Are you talking control grid or screen grid? My understanding is that the control grid sees the same drive power whether grounded grid or grounded cathode operation. Incorrec
Control grid. In AB1 there is no power consumed, in GG it is no longer AB1. Carl KM1H _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com
Yah can't get much less than zero<:-)) 73 Roger (K8RI) _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
ORIGINAL MESSAGE: REPLY: GG can be any class. Which class it is depends on the bias voltage and drive level. 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@cont
Try it sometime with a 4CX250 and tell us all what you get for power out in those classes. Carl KM1H _______________________________________________ Amps mailing list Amps@contesting.com http://lists
Bill Orr specifically says in his notes that the "supper cathode driven mode" is NOT recommended for the 4CX250 family of tubes. 73 Gary K4FMX _______________________________________________ Amps mai
ORIGINAL MESSAGE: REPLY: Different issue. As you go from class A to AB1 to AB2 to B to C, both power output and efficiency increase. That's true for all tubes, not just the 4CX250. 73, Bill W6WRT ___
Definitions: The Collins 30S1 is called a "cathode driven" amplifier not a "grounded grid" amplifier. Even though the grid and screen are at RF ground the DC grid and screen voltages are not at groun
Not when using a tetrode. 73 Gary K4FMX _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
The 4CX250 actually can be run in AB2 as it can stand a couple of watts of grid dissipation. There are AB2 specs for that tube. The 4CX1000 is only rated for AB1 operation. Zero grid current, howeve
That seems strange as the grid is rated at zero watts dissipation. 73 Roger (K8RI) _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/ma