Hi Oskar,
Quote:
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Originally Posted by Oskar.B
I have negotiated a new deadline with my tutor at the University, 23 January. More realistic than 12 December  . He was very understanding, so it was no problem to move the presentation .. phew |
Excellent, that does feel a bit more realistic. Especially since you are still waiting for some key components.
Speaking of components, then I just did the math 'properly' for your 807 PA stage, just to get an idea of how far off/close in our previous estimate of the RF load impedance was.
At 450V for B+ and Ia = 80mA, I get Rl = 2860 ohm for class C, which is pretty close to our previous estimate. Carrier power output is 25W before circuit losses, which usually runs around 10%.
If we use the commonly used value of 12 for the loaded Q and an operating frequency of 3.7MHz, I get the following component reactances/values (parasitic/stray capacitances not included, of course):
Xc4 = 238 ohm => C4 = 181pF.
Xl1 = 268 ohm => L1 = 11,5uH.
Xc5 = 31,4 ohm => C5 = 1370pF.
Frank N.