[Elecraft] JT65A output power variations.

[hb9ari]

Hi Julian,

I choose USB to be able to use VOX; may be i'm wrong, but
with DATA A, the TX activation is only possible with COM or PTT?
(it's the case for my "old" FT857)
 
As i use rarely voice modulation, the front panel I/O receptacles
are free, i don't have the necessity of a TX activation
with lot of problems like  RTS? and/or DSR?, DTR?, etc.
The serial K3 is always connected to PC, and sometimes activated
at the same time with WSJT and JT65-HF, for other programs like HRD,etc
I prefer to use a LINE Input for the K3 to get a better
SNR; i get sometimes bad results when using a MIC input
level for modulation from sound card...
I agree with you to avoid any level of compression and this level
is always set to "0" , during my (rare) voice QSO too.

I worked before for Broadcast TV and, before digital audio/video transfer,
LINE level was always preferred, when possible, to MIC level for audio.
One more point for LINE level, is value is +/- well defined, for MIC level,
it's an other story...

73 QRO de Rudolf, HB9ARI




Julian, G4ILO wrote:
> I don't understand why anyone would use USB mode to operate a sound card data
> mode, and have all the bother of switching the input between the mic socket
> and the back panel, when the K3 provides a data mode with EQ flat and
> compression off specifically for that purpose.
>
> Surely using a digimode set up for SSB with ALC operating and 20dB of
> compression is going to cause distortion and splatter? Admittedly, JT65A
> isn't PSK31 but even so I would have thought IMD products would occur,
> though if you are operating on some VHF band and not the crowded digital
> sector of 20m perhaps no-one will be bothered?
>
> I find my K3 produces more than ample output to drive sound card apps. I am
> currently using LIN OUT = 10. In fact if I use much higher levels clipping
> occurs somwhere and I see harmonics on the waterfall spectrum.
>
> On transmit the wave and master output sliders of my SB Live 24 card are set
> to just below half way and the LINE level is currently set to 7. So I cannot
> explain why you find the K3 line input insensitive or a lack of drive on
> receive.
>
> -----
> Julian, G4ILO. K2 #392  K3 #222.
> * G4ILO's Shack - http://www.g4ilo.com
> * KComm - http://www.g4ilo.com/kcomm.html
> * KTune - http://www.g4ilo.com/ktune.html
>
>