Efficiency % =
power output divided by (Plate volts times Plate current)
The quantity in parentheses is the power into the amplifier final circuit.
Good luck
Don
N8DE
Quoting Jeff Carter <amps@hidden-valley.com>:
> 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
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|