[Elecraft] Conditions, shmonditions: DXing anyway

[Fred Jensen]

This probably is related to the commercial CW operators trick of laying 
the phones down on the desk to copy a weak ship station through noise.  
It really does work. Unfortunately, today's over-the-ear headphones tend 
to stick together rather than laying flat on the desk as the old "cans" 
did, but it still works.  Tailoring the K3 RX equalizer for your ears 
and headphones/speaker is well worth some time and effort too, even on 
CW with narrow bandwidths.  You just have to go slowly and evaluate each 
setting before changing anything.

In SE Asia in the mid 60's, we used 11.5 KVA 400 Hz turbine generators.  
The primary reason was weight.  A 10 KVA  60 Hz diesel MB-5 was 
trailer-mounted and weighed about 3,500 lbs [1,600 kg].  Two troops 
could carry the turbine units, and of course, the 400 Hz power supplies 
were correspondingly lighter too.  A side benefit was that the high 
frequency whine of the turbines, running at around 9,000 RPM, was very 
easy to muffle with a few sandbags [generators were small].  The low 
frequency rumble from the 60 Hz generators was essentially impossible to 
suppress.

High frequencies seem to come forward, straight off a speaker and with 
compromised hearing, I lose intelligibility if I move off to the side.  
If I am having a hard time understanding you, speaking louder won't help 
much, speaking directly at me usually will.

73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 9/21/2018 1:03 AM, Jim Brown wrote:
> On 9/21/2018 12:22 AM, David Cutter via Elecraft wrote:
>> On a related tack, I am often surprised at how high the radio volume has
>> become in the club shack. On turning it down, it is quite a relief on 
>> the
>> ears and yet perception of the signal we are listening to improves.
> Two possible reasons. First, if a radio has a relatively low power 
> audio output stage, higher sound levels are more likely to drive it 
> into distortion. Loudspeakers, especially cheaper ones, also distort 
> more at higher power levels.  Second, reverberation and echoes are 
> "noise" as far as speech intelligibility is concerned; while that IS a 
> linear ratio, human hearing is not, so reducing the level may bring 
> those echoes/reverb down to a level where it is less perceived.
>>   It is also significant that a separate loudspeaker on a shelf being 
>> more in line with our ears provides significant improvement in our 
>> ability to "hear" the station.
>
> Exactly right, and that is ENTIRELY the result of 1) loudspeaker 
> directivity -- lows are more omni-directional from nearly all 
> loudspeakers, while the highs becomes increasing directional. [This is 
> due to wavelength of the sounds as compared to the size of the 
> loudspeaker diaphragm.] When we and the loudspeaker are facing each 
> other, we're getting both highs and lows. When the speaker is turned 
> away from you,  we hear the lows but not the highs, AND those highs 
> spray to whatever surface they face, and bounce around to create echoes.
>
> 2) The higher speech  frequencies are most responsible for speech 
> intelligibility, lows provide almost none.
>
>>   Louder is not better.
>
> Louder is only one part it.
>
> 73, Jim K9YC