[Elecraft] [K3] Fw: New 3.41 IMPROVED RX LOW-FREQUENCY RESPONSE in AM/SSB/CW MODES

[Don Wilhelm]

Tom,

For AM, the K3 shows the audio channel width, not the IF width.
Add to that, the upper audio frequency on the K3 is limited to about 4 kHz.
The IF width of an AM signal is twice the audio channel width.  In other 
words, reception of AM with a 4 kHz audio channel requires an IF channel 
at least 8 kHz wide.
You are getting more with the FM filter than you would with the 6 kHz AM 
filter - if you were using the 6 kHz filter the audio bandwidth would be 
constrained to about 3 kHz even though you could set the DSP high 
frequency to 4 kHz.

You may have to increase the value of the coupling capacitors in the 
audio output of the K3 to hear the lower bass response better.

73,
Don W3FPR

TomB W1PKX wrote:
> In AM receive I don't see any difference with previous (3.30) release. The
> 50 Hz RX EQ slider has no effect as before. I haven't measured it, but the
> Low cutoff still seems to be ~100 Hz.
>
> I notice in AM, with SHIFT=1.50,LO=0.00and width=5.00 the HI shows 4 Khz. I
> don't understand that. If I set SHIFT=1.7 then the HI goes to 4.2 Khz. In AM
> I have the FM filter selected.
>
>
> Tom
>   
>