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Able2fly

OT: math question

How would one calculate the amplifier gain (in dB) required to go from one
power level to another? For example from 5W to 100W.

K3UJ
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Don Wilhelm-3

RE: OT: math question

dB = 10 log (P2/P1)
For your example of 5 watts to 100 watts, is an increase of 13.01029996 dB -
pardon the rounding but that is all the digits my calculator shows :>).

73,
Don W3FPR

> -----Original Message-----
>
> How would one calculate the amplifier gain (in dB) required to go
> from one
> power level to another? For example from 5W to 100W.
>
> K3UJ

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S55M

Re: OT: math question

dBm's

Just remember this (no maths:))) :
Every 3dB increase is power multiplied by 2 times (1W to 2W is 30dBm to
33dBm)
So 1W+3dB (1x2=2) is 2W+3dB (2x2=4)4W+3dB(4x2=8)8W and so on.
Every 10dB increase is power multiplied by 10 (1W to 10W is 30dBm to 40dBm
100W to 1KW is 50 dBm to 60 dBm the easy one HI)
And dont care abt digits on calcullator (try to see 0,5dB on Your S-meter or
ask someone on the band to change the power from 100W to 50W or from 10W to
5W (3dB) You will see practically no difference.
Why dBm? Because dBm is power related to 1mW=0dBm .

S55M-Adi

----- Original Message -----
From: "W3FPR - Don Wilhelm" <[hidden email]>
To: <[hidden email]>; <[hidden email]>
Sent: Wednesday, March 30, 2005 8:23 PM
Subject: RE: [Elecraft] OT: math question

> dB = 10 log (P2/P1)
> For your example of 5 watts to 100 watts, is an increase of 13.01029996
dB -

> pardon the rounding but that is all the digits my calculator shows :>).
>
> 73,
> Don W3FPR
>
> > -----Original Message-----
> >
> > How would one calculate the amplifier gain (in dB) required to go
> > from one
> > power level to another? For example from 5W to 100W.
> >
> > K3UJ
>
>
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Tom Hammond-3

Re: OT: math question

In reply to this post by Able2fly

At 12:01 PM 3/30/05, you wrote:
>How would one calculate the amplifier gain (in dB) required to go from one
>power level to another? For example from 5W to 100W.

10 log(P2/P1) = 10 log(100/5) = 10 log(20) = 10 (1.30103) = 13.0103dB

An easy 'rule of thumb' way to get a good idea of such levels
is to remember that:

a power INcrease of 2 = approx. +3dB change
a power DEcrease of 2 = approx. -3dB change

a power INcrease of 10 = +10dB
a power DEcrease of 10 = -10dB

So, to go from 5W to 10W output, you have 3dB GAIN
to go from 10W to 100W, you have 10dB gain

Since dB's can be added, going from 5W to 100W = 3db + 10 dB = 13dB

Similarly, if you went from 2W to 800W...

From 2W to 4W (first doubling of power) = +3dB
From 4W to 8W (2nd doubling of power) = +3dB
From 8W to 800W (increase of 10X) = +10dB
-------
Total power increase in dB = +16dB

73,

Tom Hammond N0SS

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K6TFZ

Re: OT: math question

In reply to this post by Able2fly

In a message dated 3/30/2005 10:02:44 AM Pacific Standard Time,
[hidden email] writes:

How would one calculate the amplifier gain (in dB) required to go from one
power level to another? For example from 5W to 100W.

The formula is: dB = 10 log (P2 / P1)

P2 / P1 = 100 / 5 = 20

log of 20 = 1.30103

10 times it = 13.0103

That's your answer: 13.0103 dB

Geoff, K6TFZ
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Tom McCulloch

Re: OT: math question

In reply to this post by Able2fly

Im with Adi on this one..i.e NO MATH!. Although I'm 100% certain Don is correct, my "fingers" came with *about* a 12.6 dB increase. (I never did understand those loggers)
Tom
WB2QDG
K2 1103

-------------- Original message ----------------------
From: "S55M" <[hidden email]>

> dBm's
>
> Just remember this (no maths:))) :
> Every 3dB increase is power multiplied by 2 times (1W to 2W is 30dBm to
> 33dBm)
> So 1W+3dB (1x2=2) is 2W+3dB (2x2=4)4W+3dB(4x2=8)8W and so on.
> Every 10dB increase is power multiplied by 10 (1W to 10W is 30dBm to 40dBm
> 100W to 1KW is 50 dBm to 60 dBm the easy one HI)
> And dont care abt digits on calcullator (try to see 0,5dB on Your S-meter or
> ask someone on the band to change the power from 100W to 50W or from 10W to
> 5W (3dB) You will see practically no difference.
> Why dBm? Because dBm is power related to 1mW=0dBm .
>
> S55M-Adi
>
>
> ----- Original Message -----
> From: "W3FPR - Don Wilhelm" <[hidden email]>
> To: <[hidden email]>; <[hidden email]>
> Sent: Wednesday, March 30, 2005 8:23 PM
> Subject: RE: [Elecraft] OT: math question
>
>
> > dB = 10 log (P2/P1)
> > For your example of 5 watts to 100 watts, is an increase of 13.01029996
> dB -
> > pardon the rounding but that is all the digits my calculator shows :>).
> >
> > 73,
> > Don W3FPR
> >
> > > -----Original Message-----
> > >
> > > How would one calculate the amplifier gain (in dB) required to go
> > > from one
> > > power level to another? For example from 5W to 100W.
> > >
> > > K3UJ
> >
> >
> > _______________________________________________
> > Elecraft mailing list
> > Post to: [hidden email]
> > You must be a subscriber to post to the list.
> > Subscriber Info (Addr. Change, sub, unsub etc.):
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> >
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> > Elecraft web page: http://www.elecraft.com
>
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AD5MA

Re: OT: math question

In reply to this post by S55M

And while we're on the subject... the correct unit is dB, not dBm.

Remember that dB is a relative term. In the case of amplifier gain, this is
relative. The unit dBm is an absolute unit relative to 1 milliWatt. When the
amplifier is finally built, it will have 50 dBm of output power (assuming it
is driven with enough input signal) and will have 13 dB of gain.

Al.

----- Original Message -----
From: "S55M" <[hidden email]>
To: <[hidden email]>; <[hidden email]>; <[hidden email]>
Sent: Wednesday, March 30, 2005 12:41 PM
Subject: Re: [Elecraft] OT: math question

> dBm's
>
> Just remember this (no maths:))) :
> Every 3dB increase is power multiplied by 2 times (1W to 2W is 30dBm to
> 33dBm)
> So 1W+3dB (1x2=2) is 2W+3dB (2x2=4)4W+3dB(4x2=8)8W and so on.
> Every 10dB increase is power multiplied by 10 (1W to 10W is 30dBm to 40dBm
> 100W to 1KW is 50 dBm to 60 dBm the easy one HI)
> And dont care abt digits on calcullator (try to see 0,5dB on Your S-meter
or
> ask someone on the band to change the power from 100W to 50W or from 10W
to
> 5W (3dB) You will see practically no difference.
> Why dBm? Because dBm is power related to 1mW=0dBm .
>
> S55M-Adi
>

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crmabbott

RE: OT: math question

In reply to this post by Able2fly

I like simple, 10Db gain will go from 5 to 50Watts; 3Db more will double 50
to 100 Watts. Approximately 13 Db

--
73
Chuck AA8VS
www.aa8vs.org/aa8vs
FP #113 MI-QRP #1212 SOC #445
Firebird #2117 TSARC #3952

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of [hidden email]
Sent: Wednesday, March 30, 2005 1:02 PM
To: [hidden email]
Subject: [Elecraft] OT: math question

How would one calculate the amplifier gain (in dB) required to go from one
power level to another? For example from 5W to 100W.

K3UJ
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Tom Hammond-3

Re: OT: math question

In reply to this post by Tom Hammond-3

Hi Frank:

Thanks pal... guess I got a bit ahead of myself there!

Of course, you're completely correct! Should have been 26db, instead of 16dB!

73,

Tom

At 03:54 PM 3/30/05, you wrote:

>Hi Tom,
>Just a small correction to your 2W to 800W example:
> From 2W to 4W (first doubling of power) = +3dB
> From 4W to 8W (2nd doubling of power) = +3dB
> From 8W to 80W (increase of 10X) = +10dB
> From 80W to 800W (increase of 10X) = +10dB
>Total = 3+3+10+10 = 26db
>
>Best 73,
>Frank - W6NEK
>
>----- Original Message ----- From: "Tom Hammond" <[hidden email]>
>To: <[hidden email]>; <[hidden email]>
>Sent: Wednesday, March 30, 2005 11:01 AM
>Subject: Re: [Elecraft] OT: math question
>
>
>>At 12:01 PM 3/30/05, you wrote:
>>>How would one calculate the amplifier gain (in dB) required to go from one
>>>power level to another? For example from 5W to 100W.
>>
>>10 log(P2/P1) = 10 log(100/5) = 10 log(20) = 10 (1.30103) = 13.0103dB
>>
>>An easy 'rule of thumb' way to get a good idea of such levels
>>is to remember that:
>>
>> a power INcrease of 2 = approx. +3dB change
>> a power DEcrease of 2 = approx. -3dB change
>>
>> a power INcrease of 10 = +10dB
>> a power DEcrease of 10 = -10dB
>>
>>So, to go from 5W to 10W output, you have 3dB GAIN
>> to go from 10W to 100W, you have 10dB gain
>>
>>Since dB's can be added, going from 5W to 100W = 3db + 10 dB = 13dB
>>
>>Similarly, if you went from 2W to 800W...
>>
>> From 2W to 4W (first doubling of power) = +3dB
>> From 4W to 8W (2nd doubling of power) = +3dB
>> From 8W to 800W (increase of 10X) = +10dB
>> -------
>> Total power increase in dB = +16dB
>>
>>73,
>>
>>Tom Hammond N0SS
>>
>>_______________________________________________
>>Elecraft mailing list
>>Post to: [hidden email]
>>You must be a subscriber to post to the list.
>>Subscriber Info (Addr. Change, sub, unsub etc.):
>>http://mailman.qth.net/mailman/listinfo/elecraft
>>Help: http://mailman.qth.net/subscribers.htm
>>Elecraft web page: http://www.elecraft.com
>

N8LP

Re: OT: math question

In reply to this post by Tom Hammond-3

For convenience, Mini-Circuits has a nice printable conversion table at
http://www.mini-circuits.com/dg03-110.pdf

Larry N8LP

Tom Hammond wrote:

> At 12:01 PM 3/30/05, you wrote:
>
>> How would one calculate the amplifier gain (in dB) required to go
>> from one
>> power level to another? For example from 5W to 100W.
>
>
> 10 log(P2/P1) = 10 log(100/5) = 10 log(20) = 10 (1.30103) = 13.0103dB
>
> An easy 'rule of thumb' way to get a good idea of such levels
> is to remember that:
>
> a power INcrease of 2 = approx. +3dB change
> a power DEcrease of 2 = approx. -3dB change
>
> a power INcrease of 10 = +10dB
> a power DEcrease of 10 = -10dB
>
> So, to go from 5W to 10W output, you have 3dB GAIN
> to go from 10W to 100W, you have 10dB gain
>
> Since dB's can be added, going from 5W to 100W = 3db + 10 dB = 13dB
>
> Similarly, if you went from 2W to 800W...
>
> From 2W to 4W (first doubling of power) = +3dB
> From 4W to 8W (2nd doubling of power) = +3dB
> From 8W to 800W (increase of 10X) = +10dB
> -------
> Total power increase in dB = +16dB
>
> 73,
>
> Tom Hammond N0SS
>
> _______________________________________________
> Elecraft mailing list
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>
>

Bob P-2

Re: K1 Hum

Hi All,

My K1 is out traveling with me, getting a lot of low sounding distortion
(hum) and key clicks when sending.

This radio is a used one I picked up on ebay and seemed to work OK at home.
BTW at home I was using my bencher paddle, now I'm using a new PAL I
purchased.

Bob KC8IPQ

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Bob P-2

Re: K1 Hum Solved

Thks for the replies,

A/C hum was from my laptop puter, I split feed the out put to mixw to check
on signals and zero beat. Moving it away from K1 did the trick.

Bob KC8IPQ

----- Original Message -----
From: "ROBERT PHILLIPS" <[hidden email]>
To: <[hidden email]>
Sent: Thursday, March 31, 2005 7:53 PM
Subject: Re: [Elecraft] K1 Hum

> Hi All,
>
> My K1 is out traveling with me, getting a lot of low sounding distortion
> (hum) and key clicks when sending.
>
> This radio is a used one I picked up on ebay and seemed to work OK at
> home. BTW at home I was using my bencher paddle, now I'm using a new PAL I
> purchased.
>
> Bob KC8IPQ
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
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> Elecraft web page: http://www.elecraft.com
>