Congratulations! It's such a rush to work on something like that and
see it work when you're done.
To answer your questions, I have to say it's been a while, and I'm
sure AMPS will jump in and correct me if I'm wrong, but here's how I
*think* I remember that this is done.
For gain in dB, I think it's 10*log(power out/power in). So in your
case, it's 10*log(450/20), or 10* log(22.5)= 13.5218251811 db.
For efficiency, it's basically how much of the power is used and how
much is turned into heat, and I can't for the life of me remember how
that's calculated.
I bet Dan knows...and he's much better with the math than I am.
Jeff/KD4RBG
---- Original message ----
>Date: Thu, 5 Mar 2009 14:39:35 -0600
>From: "KB0NLY" <kb0nly@mchsi.com>
>Subject: [Amps] An Extra Thank You!
>To: <amps@contesting.com>
>
>Just wanted to post an extra Thank You to the reflector for all those that
>have been patient with me and helping. My 6M amp project has been completed!
>It was powered up and brought to life today finally after much careful
>planning and building.
>
>Initial tests prove it's working rather well!
>
>Input 20w
>Output 450w
>Plate 375mA
>Grid 80mA
>
>I was told to keep the GI7B at or below 400mA on the Plate and 150mA on the
>Grid, i can do that easily. It will make a bit more power but it's maxing out
>my wattmeter now!
>
>I do have one final question for everyone here. Knowing these numbers, input,
>output, plate and grid, how does one calculate the amp's gain and or
>efficiency? I was trying to make sense of the info in the handbook but it was
>slightly over my head with all their calculations. I'm looking for an Elmer
>answer on this one!
>
>Thanks and 73!
>
>Scott KBØNLY
>
>PS: I will finish updating my website this afternoon with pictures of the
>completed amp.
>
>www.kb0nly.net
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