|Joined:||Sun, Feb 6th 2011, 20:24||Roles:||N/A||Moderates:||N/A|
|Delta loop 4NEC2 model||Nov 28th 2012, 21:27||2||1,875||on 29/11/12|
|4CX250B cathode driven input impedance||Jan 6th 2012, 15:30||1||1,657||on 6/1/12|
|Delta loop 4NEC2 model||IW3GHD||on 28/11/12|
|I'd like to post a full parametric 4NEC2 model of a single element (just for now) delta loop antenna which includes a gamma match. If you run the optimizer for example one can find the minimum SWR and/or the resonance condition (min Xin) by playing with antenna perimeter, wire diameter, pigtails parasitic elements, gamma rod length or spacing as well as the gamma capacitance.
|4CX250B cathode driven input impedance||IW3GHD||on 6/1/12|
I'd like to design the matching PI input network for my 2x 4CX250B homebrew cathode driven HF amplifier and furthermore get into a deeper understanding on the optimal energy transferring from the RTX to the amplifier. I couldn't find any helpful in databook or SPICE models of such tubes.
May I get use of the PC-EL software somehow?
What is the cathod impedance in a grid grounded configuration?
Someone said 120 Ohm per tube with 15 pF or so in-parallel capacitance, but I don't have any datasheet confirmation on that.