[Elecraft] Blue Tooth - Freq. response

[Joe Subich, W4TV]

 > If one introduced say 6 db in the segment covering 2KHz and up to the
 > next equalizer breakpoint, I don't see how this can mess up decoding.
 > The gain increase is constant in the segment.

No, the gain is not constant across the segment, it is tapered so that
setting two adjacent ranges to the same level creates a flat response
across the "boundary."  In the case of 2125/2295 (traditional "high"
tones) setting the 1600 Hz band at 0 and the 2400 Hz band at +10 dB
will create a measurable "tilt" between the two tones ... a similar
tilt will be seen with the 915/1085 Hz tone pair for the 800/1600 Hz
bands.

It's easy to see the behavior, simply use a stable oscillator like the
XG-2.  Set the RxEQ to boost only the 2400 Hz band by +16 dB, zero the
dBV meter at 1 KHz and measure the level at 2.125 and 2.295 KHz.  The
difference will be at least 2 dB (I measure 2.2 to 2.3 dB "tilt" at
both 2125/2295 and 915/1085).

The behavior of a parametric EQ (which the K3 is) is very different
than a shelving EQ.

73,

    ... Joe, W4TV


On 2/7/2011 3:26 PM, Brian Alsop wrote:
> Joe,
>
> We very specifically singled out FSK-D for this request.  No other
> digital mode would be impacted.
>
> If one introduced say 6 db in the segment covering 2KHz and up to the
> next equalizer breakpoint, I don't see how this can mess up decoding.
> The gain increase is constant in the segment.
>
> 73 de Brian/K3KO
>
> On 2/7/2011 20:17, Joe Subich, W4TV wrote:
>>
>> But you don't want the equalizer in digital modes as that messes
>> up the response and results in poorer decoding. The only change
>> that makes sense in any of the digital modes is (flat) level and
>> that can be done with CONFIG: LIN OUT.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>> On 2/7/2011 2:19 PM, Brian Alsop wrote:
>>> Add "in equalizer" to the request. Right now it knows to turn it off in
>>> FSK-D.
>>>
>>> 73 de Brian/K3KO
>>>
>>> On 2/4/2011 22:41, Joe Subich, W4TV wrote:
>>>>
>>>>>> Unfortunately, one can't bump up audio output in FSK-D.
>>>>
>>>> What do you mean "can't bump up audio output in FSK-D?" The speaker
>>>> or headphone level is controllable with the AF gain and the Line Out
>>>> is controllable with the CONFIG:LIN OUT setting.
>>>>
>>>> 73,
>>>>
>>>>
>>>
>>>
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