[Elecraft] Poor Low audio frequency response on JT65 mode with my K3 ?

[Lance Collister, W7GJ]

Hi Cliff,

I assume you have been using the DATA mode, which has less receive bandwidth for some 
reason (I think it is because of the Firmware).   That is why I still always use the 
USB position for JT65.  With USB it is possible to have a much broader receive 
bandwidth.

I also lways use compression to make sure that all the tones of different frequency 
provide the same output.  The only downside to using USB position for JT65 is that 
you can't use anything other than a flat audio transmit spectrum, so I have made no 
custom TX adjustments for my microphone.

I understand that not all digital modes operate the same way, so the above settings 
might not provide the best performance for modes like PSK31.   But since JT65 can be 
operated in class C, it is pretty forgiving.  GL and VY 73, Lance



On 11/14/2012 12:04 AM, Clifford Hynds wrote:
> Hope someone has an answer,
>
> I am a recent owner of the K3 having just bought a K3, P3 and KPA500
> station from another ham.
>
> Probably you would have to be a regular user of the JT65 mode to notice but
> I seem to get little or no output when I am below about -500hz or so on the
> waterfall on JT65HFand nothing really at -1000Hz, fine from there up.
>
> Probably affect other data modes also ?
>
> I am using line in/out on the K3 and DATA mode so no equalisation,
>
> Had no problems with other rigs FT847,FT817 and TS950SDX had no problems
> with the low end.
>
> Could be as simple as increasing the input capacitor for the line audio or
> as the audio is controlled by the DSP perhaps an upgraded DSP unit. The K3
> is in the < 1000 Serial numbers 718 if i remember not in front of it at the
> moment.
>
> Hope someone has an answer,
> thanks
> Cliff VK2CCJ
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-- 
Lance Collister, W7GJ
(ex WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8, E51SIX, 3D2LR, 5W0GJ, E6M)
P.O. Box 73
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