[Elecraft] RTTY Problems

[Don Wilhelm]

Dohn,

You can always tune the PSK31 signal with the K2 VFO so the audio will 
appear near 2210 Hz rather than the more traditional 1000 Hz.  But many 
RTTY software packages offer another alternative - adjust the RTTY tones 
in the RTTY software.

I believe the better way is to tell the RTTY software to use lower tones 
  rather than the traditional 2210 Hz center.  Of course that cannot be 
done if one is using a hardware TU which does not implement a switch for 
low tones.  The traditional "Low Tones" for RTTY is 1275 mark and 1445 
space - only the shift amount is critical.  If you have your PSK31 
filters set for 1000 Hz center and you can tell the RTTY software to use 
  915 Hz mark and 1085 space tones both RTTY and PSK31 signals can be 
received with the narrow RTTY filters at a 1000 Hz center.

Remember that with all digital modes, the SSBC parameter should be set 
to 1:1 for the lowest IMD and that RTTY FL1 must be set to OP1 (or OP2, 
3, 4 or 5 - they are the same).  Adjust the RTTY FL1 BFO to be the same 
as those for SSB and all will be well on transmission.

73,
Don W3FPR


Dohn wrote:
> If one centers their filters at 2210 Hz in RTTY mode for use in RTTY, then
> is RTTY no longer the mode of choice for PSK31?  Would you just use USB for
> PSK31 and adjust your speech compression?  Are RTTY and PSK31 both useable
> with RTTY mode with filters centered around 2210 Hz?
> 
> Dohn N8EWY 
> 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Steven Pituch
> Sent: Saturday, March 17, 2007 5:29 PM
> To: Elecraft
> Subject: Re: [Elecraft] RTTY Problems
> 
>> (The crystal filters in RTTY mode are unusable for
>> RTTY because they're centred on voice audio
>> frequencies and not RTTY freqs.  But that's another
>> story.)
> Hi Ken,
> As far as the other story goes....center them on 2210 Hz or whatever the 
> RTTY center frequency is, then narrow them down to about 400 hz wide and 
> then it will work fabulously.  My PK232 is centered on 2210 Hz so I aligned 
> the K2 filters to match.  Now I can do PACTOR I with my K2.
> See:
> http://www.pituch.net/p/Steve's%20Page/Radio/RTTY/RTTY.html
> or just page down from www.pituch.net
> 
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