[Elecraft] K2, low output in digital modes

[Don Wilhelm]

Raimon,

If you have the RTTY FL1 filter set to OP1 and the BFO frequencies set 
the same as for SSB, there should be no difference.
EXCEPT
The RTTY filter set has an independent SSBCr setting in the menu, and it 
should always be set to 1-1 for data modes.
If you have the SSB menu SSBC set to add compression to the signal, that 
would explain the difference, but if so, it is causing distortion on 
your data signal.

Yes, you will have to increase the audio gain on the higher bands where 
the transmit gain is lower.

Re-check the filter settings.  If the FL1 filter is set to OP1 and the 
BFOs are set the same as for SSB, then there should be no difference if 
you set the SSBC menu parameter to 1-1.

73,
Don W3FPR

raimon wrote:
> Hi Elekrafters
>
> I need your help.
>
> My K2/100 nr. 03529 with KSB2 SSB adapter and KAT 100 Antenna Tuner has 
> been working perfectly since I built it, with the exception of some 
> minor problems that were solved either with the help of Don Wilhelm or 
> after a search in the e-mail list reflector.
>
> But now I detected a problem unnoticed until now:
>
> I work mainly CW and digital modes.
>
> In 40, 30 and 20 meters, in PSK 31 or RTTY, I could get easily about 40 
> watts output, corresponding to one bar flickering in ALC bargraf. So all 
> was apparently all right.
>
> But I have tried recently the 10 m. band and noticed that when selecting 
> my RTTY filters configuration I can get only near 20 watts in rtty, and 
> less than 10 watts in rtty-r.
>
> When I use in this band the USB or LSB configuration, and transmit RTTY 
> or PSK, I get about 90 watts, the same output as in CW..
>
> I have seen now that this drop in output happens in all bands, but I 
> had’nt noticed it because I was able to get 30-50 watts in the lower 
> bands, even in RTTY configuration. The same output drop happens in QRP 
> configuration.
>
> Summarizing, in digital transmissions when in RTTY the output is 
> significantly lower than when in SSB, and the higher the frequency the 
> lower the output power.
>
> I realigned my filters with the help of Spectrogram, applying the same 
> settings for OP-! SSB and OP-1 RTTY (there were some small differences 
> before this realignment), but to no avail.
>
> Although I can continue working digital modes using the SSB 
> configurations, I would like to know the reason of this behaviour and 
> how to solve it.
>
> Your help will be greatly appreciated.
>
> Best regards
>
> Raimon
>
>
>