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-- In ham_amplifiers@..., "Mike\(W5UC\) &
Kathy&#92;(K5MWH&#92;)" <w5uc@...> wrote:
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#### then click on..."stuff" I tried the pi net for my tuned inputs.... and it's slick.... since it does ALL bands at once. By tweaking the Q in tiny increments... it spat out virtually identical results to what we are using on both the 3000 A7 amp.. and the 6000A7 amp. Now here's the kicker..... the tube's input Z may be a little lower than 50 ohms in my case.... and when feeding with 50 ohm coax.... u will end up with a conjugate match... so allow leeway [esp on 160m].. esp on the C2 cap closest to cathode.

When I put the sheet together, I was concerned that it wouldn't do tuned inputs well so I am glad to hear that it actually worked there.

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## Have not tried the pi spread sheets for big pi output... yet. Dunno whether they factor in the stray L between anode and PI or not.. as this has a huge effect... since any stray L b4 the PI will drop/transform the plate load Z.. like a rock... which is fine... but the PI has to be designed around a lower plate load Z.

No real factor for strays since they are different for every situation and tube. It wouldn't be that difficult to add a field so you could plug in your own strays and then let it use those for the final output.

all in all... superb sheet. Gotta spend more time with it. It would be nice to have something that calculates the expected peak/rms currents and rf voltages across all the components.... including the plate block cap, anode to chassis path, C1 C2... and coil... + ant current. Then it makes it easier to size stuff. later.... Jim VE7RF

Now that's an idea... I'd be happy to take a stab at including such things. We'll have to talk off line and see what you'd want.

I didn't make that thing as a cure all, but I really did want a tool to do "what if" with and displaying all the bands data at one time was a big part of that.

Thanks for your comments.

73, Tony W4ZT