Yes, the pi net design values for 4KW PEP are quite different to 1.5KW. If designed for 4k, circuit Q will be almost doubled for 1.5k. And I doubt it can be tuned on 10m with that high tube impedance
HV fuses are still produced: https://kentec.net/pdf/eska/eska46.pdf https://www.eskafuses.com 73 Peter Time to make your own from an open one or start from scratch.. Carl -- Original Message -- From:
Yes, anode tuning must be for maximum screen current with the anode capacitor and loading capacitance for maximum output power and screen current limit. OM Power is mixing it up in their "how to tune
No Jim, A PP RF amplifier does not need LP filters if using pi-net output circuitry. And a GG amplifier running class B does not generate key clicks, my main amp is running zero bias class B for more
Try the Marconi design. Page 96, figure 7.1 of ?Radio Transmitters? by V.O.Stokes 73 Peter The inserted picture was probably too large "Just shoot amongst us. . . One of us needs some relief ! " Draw
Another concept for your ice show: http://www.qrp4u.de/docs/de/PL519/index.htm 73 Peter "Just shoot amongst us. . . One of us needs some relief ! " Draw me a skezmat of a push-pull Pi-Net. I may want
Jim, OK, I read it in the context with tube GG amps. I donīt use zero bias triodes in my glass tube amps but highĩ connected tetrodes. The pair of RS1002A in my L4B draw only 30mA, no key clicks and
I donīt think so und would never allow less then 7V and rather stay above 7.1V. With 6.5V you wanīt get enough heating power for the cathode. 73 Peter Fil V set for 6.5 vac. Tube will last forever. _
My 3CX3000F7 does well on 2m. 73 Peter Conrad, I built a 150MHz amp using a 3cX20000 for an industrial customer. This tube is rated at 110mhz buts worked fine at 150. Did 24kw out - could have gotten
What for? The current remains the same. And overall efficiency is probably better then with a switcher when a toroid core is used for the transformer. 73 Peter For tubes like this, BIG currents on th
He should have used an artificial center tap. Two low ohm resistors in series across the heater winding, between them connect the ground, works very well. 73 Peter < Seems to me this problem may not
I bought a 8V 80A transformer in the Netherlands: http://www.elektrodump.nl/en/ They offer modulation transformers custom made, so probably can wind heater transformers as well. 73 Peter Thanks every
I bought 500VA and 750VA toroid core transformers from a German factory without secondary windings, just the primaries. I used them to wind my heater transformers in the past, if I remember right the
I donīt understand the "boost" question on the screen voltage. The 4CX1500B should be run at 225V screen voltage as AB1 RF linear. The voltage for the 4CX1000A is higher already. 73 Peter Gord, you'r
For more power you will need more drive. 73 Peter Recently purchased set of 3-500 tubes Made PRC and installed in AL82 amp This AL82 had the Zener diodes replaced with diode string before I purchased
In my opinion -26dB IP3 is terrible with qro, probably acceptable with qrp. 73 Peter, DJ7WW Apparently the measured IP3 was -26dB relative to either one of two tones which corresponds to -32dB relati
I used stacks of T225-2 for a mobile antenna loading coil on 40m. Measured Q was around 400. Toroid coils with taps, which no good idea anyway, will have much lower Q. As part of a pi network for 160
Hi John, With the Q of 7 to 8 you probably mean the pi network Q. That is not the Q of the particular coil but that of the circuit, calculated by tube Ra/Xc of anode capacitor. Higher Q will produce
Excellent stuff, I use it since 1976. Over here it is not that expensive, 2,80 per meter. 73 Peter How long of a run? Bite the bullet... Andrew / Comscope LDF4-50. Lasts forever! If you live near Spr
Except probably in your country a 3 wire 240V mains connection is standard. There is the active phase, neutral and safety ground. The way a L4B is connected is always fine in Europe. Same with the Co