[Elecraft] Re: RTTY Mode Filter Settings for PSK31

[Julian, G4ILO]

Hi Don.

Actually, I don't think anything I've done is original. The idea came from 
a couple of other people, one of whom had used a similar scheme with his 
IC-756Pro.

The problem of sending and receiving using different filters means that you 
have to try and minimise the frequency shift between the different filters 
as far as possible. Since it isn't possible to entirely eliminate this I 
use the LOCK command in the macro that switches in the narrow filter. This 
locks the TX on the received station's frequency so that you can then use 
the cursor in the waterfall to re-click on the signal to compensate for any 
apparent frequency shift without changing the frequency you reply on. Of 
course, this means that you must always go back to the wide filter setting 
to select another station to work, but it isn't hard to remember to do 
this.

I actually set up three macro keys to do this, all on the numeric key pad. 
Gray * centers the signal to 1200Hz, which is approximately the center of 
my SSB filter and the center frequency for my narrow RTTY filters as well. 
I'm not suggesting this frequency is necessarily optimum for PSK, and some 
K2s might experience less frequency shift between wide and narrow filters 
if you use a different center frequency. I use a similar approach on CW 
where the frequency I use is 800Hz, except that it isn't necessary to lock 
the TX frequency or use the SNAP commands.

The macros I use are:

Gray* (Align): <UNLOCKTX><CATCMD:FW00001;><ALIGN:1200><SNAPNOW>
Gray- (Narrow): <LOCKTX><CATCMD:FW00002;><SNAPNOW>
Gray+ (Wide): <UNLOCKTX><CATCMD:FW00001;>

--
Julian, G4ILO. (RSGB, ARRL, G-QRP)
G4ILO's Shack: http://www.qsl.net/g4ilo





  ==== Original message ====

> Julian,
> Your technique for using narrow filters is interesting - and seems VERY
> desirable.
> My question is:  How do you reconcile the fact that the K2 always uses 
> the
> FL1 filter for transmit?  You must be establishing some relationship so 
> the
> transmit signal and the receive frequency are matched.  Not impossible, 
> but
> it will ease my brain-work if you have already solved this problem.
> 
> Also, could you pass along the MixW macro that you are using to center 
> the
> desired signal - I do have the KIO2 interface, so no problem there.
> 
> You have put a lot of effort into using the K2 for PSK31 operation - 
> have
> you put some 'how-to' notes on a webpage somewhere?  Perhaps that would 
> be a
> good topic to have available on the Elecraft site.
> 
> 73,
> Don W3FPR
>