I said for example 2200V and turned around and used 2000V in the
calculations.
Roger wrote:
> Jeff Carter wrote:
>
>> 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.
>>
>>
>>
> IIRC For efficiency it's pretty straight forward it's power out divided
> by power in (not drive) IOW in this case for GG it's Plate current Ip
> (0.375 * multiplied by plate voltage. I don't remember what you are
> using for voltage, but as n example if the plate is 2200 then
> 0.375A*2000V=750 Watts input power plus 20 watts of drive for 770 watts
> input or 450/770 = 58% overall efficiency for the amp. The tube
> efficiency would be 450/750 or 60%
>
> 73
>
> Roger (K8RI)
>
>> 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
>
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|