[Elecraft] SSB C r Firmware command

W3FPR - Don Wilhelm w3fpr at earthlink.net
Sun Sep 26 21:00:26 EDT 2004


Tom,

You are correct that the RTTY ('r' indicator) mode gives you a compression 
setting that is independent of the SSB mode (USB or LSB) - when RTTY mode is 
selected, if one enters the menu and selects SSBC, it will display SSBCr to 
let you know that this is the setting for RTTY mode as opposed to SSB mode 
(either USB or LSB).

If your RTTY filters (and the corresponding BFO frequencies) are set the 
same as the SSB filters, you should hear the same passband.  It is not 
sufficient to simply set the passband widths the same, but you must also 
align both BFOs for each filter to match the audio range that you wish to 
demodulate.  If you need detail information on aligning the filters, look at 
my webpage (www.qsl.net/w3fpr) article dealing with K2 dial calibration - 
Step 3 is the CAL PLL section.

I am confused with your mention of CW reverse in the context of RTTY mode - 
CW reverse is an entirely different mode and will not work for PSK31 except 
in a receive only situation (transmit will make CW dots when the PTT line is 
active and in CW mode).

73,
Don W3FPR

----- Original Message ----- 

> I'm not sure I understand the K2's "SSB C r"  firmware command or if I am
> using it properly.
>
> Am I correct in stating that it's main purpose is to use a different
> compression (usually 1-1 ) than that which is set by SSB C ?
>
> I use my K2 to run PSK 31 (mostly on 20 meters) and would like to avoid
> having to turn off the compression, so this setting would make sense.
>
> I have, of course, set RTTY to "On"
>
> I have set Fl1 through FL4 to the same bandwidths for both modes but it
> seems as though I am getting a lot more PSK31 signals on my screen when I
> use the "U" mode than I do using the "r" mode.  (On 20 mtrs I am using CW
> reverse with the "r" mode - I think that is right.)
>
> This is not a big deal as I can continue using the "U" mode and manually
> change the compression setting, but I thought I should understand what the
> "r" setting is all about.
>
> Thanks
> Tom WB2QDG
> K2 1103
>
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