[Elecraft] KPA1500 design

[David Gilbert]

And although I've posted this link before, here it is again for anyone 
who missed it and wants to hear what a difference of 2 db makes.  
Actually, there are several audio files there that compare various CW 
signal levels at or near the background noise level:

a.  six steps of signal strength in one db increments

b.  two competing signals either one db or two db apart

c.  the impact of CW speed on intelligibility of signals very near the 
noise level

The methodology I used to generate the files is also described there, 
but in a nutshell I used CW Player (written by F6DQM) to record CW of 
known amplitudes and mixed them with band noise recorded from my K3.

http://www.ab7e.com/weak_signal/mdd.html

73,
Dave   AB7E



On 2/22/2012 5:30 AM, Brian Alsop wrote:
> For those who don't believe Dave, here is some suggested reading material.
>
> N6BT's new Antenna Book, Array of Light
>
> He discusses the significant difference an extra 2db makes.
>
> Yes he also sells antennas, but what he says rings true.
>
> 73 de Brian/K3KO
>
>
>
> On 2/22/2012 07:54, David Gilbert wrote:
>> Actually, a power ratio of 3 is almost 5 db, which is a huge difference
>> when you're talking signals near the noise level.  On most HF bands it
>> can literally be the difference between being Q5 versus not being
>> discernible at all.   If you think 5 db is no big deal, keep in mind
>> that the KPA500 offers only 2 db more than that (7 db total) over a
>> barefoot K3.
>>
>> Dave   AB7E
>>
>>
>> On 2/21/2012 8:55 PM, Ron D'Eau Claire wrote:
>>> Congratulations Andy!
>>>
>>> I'm mindful that data does not change beliefs, the difference is power
>>> between a KPA500 and the legal limit is slightly over 1/2 of one S unit.
>>>
>>> But for those who want to have the biggest signal, it does take the legal
>>> limit **and** a big antenna.
>>>
>>> 73, Ron AC7AC
>> ____