[Elecraft] K3 Firmware 2.10,1.81 problems Update

[Joe Subich, W4TV]

> RTTY was based upon the frequency 
> of Mark (2125) and Space (2295) and the surplus military 
> equipment available, unless you could afford some of the high 
> dollar HAL equipment (which was also used by the military). 

No, RTTY is always "Shift low" - that is Mark is the HIGHER 
RF frequency and space is the LOWER RF frequency.  When the 
audio tones 2215 and 2295 are applied to a LSB transmitter 
in AFSK this results in the correct shift. 

> I have no idea what the protocol is for DATA (perhaps Elecraft 
> can tell us.)  As an experiment, try switching rigs in MixW and 
> observe what is happening to the signal frequency.  

FSK D and AFSK A receive in LSB while PSK D and DATA A receive in 
USB for compatibility with the (backward) convention of most non-
RTTY software writers (PSK32, MFSK, etc.). 

73, 

   ... Joe, W4TV 
 




> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Rich (KE0X)
> Sent: Friday, June 27, 2008 4:49 PM
> To: elecraft at mailman.qth.net
> Subject: Re: [Elecraft] K3 Firmware 2.10,1.81 problems Update
> 
> 
> 
> As Julian suggested the problem is in MixW.  It has been 40 
> years since I had the RTTY training course in the NAVY, but, 
> it has to do with the convoluted history of RTTY.  Although 
> SSB is on the LSB on the HF bands below 30 Meters and USB on 
> those bands above 30 meters (Many reasons given for this most 
> of which are not correct) RTTY was based upon the frequency 
> of Mark (2125) and Space (2295) and the surplus military 
> equipment available, unless you could afford some of the high 
> dollar HAL equipment (which was also used by the military).  
> Military protocol was to have the Mark the lowest tone in 
> frequency. This was ok with most equipment made BPC (Before 
> Personnel Computers).  The PC brought out the conversion of 
> telephone modems, use of the modem IC’s and finally the PC 
> sound card for generating these tones. If you built a TNC out 
> of a modem chip and did not include a reverse switch you were 
> stuck to either the low or high bands.  This was fixed on the 
> PC with a button to reverse the signal that you could click 
> on and copying.  Some of the Rigs treat RTTY as SSB, others 
> put RTTY so that the Mark is always the lowest frequency 
> transmitted regardless of the band selected, and RTTYR 
> reverses this.  I have no idea what the protocol is for DATA 
> (perhaps Elecraft can tell us.)  As an experiment, try 
> switching rigs in MixW and observe what is happening to the 
> signal frequency.  You wil not be able to chang frequency 
> with MixW but you can see what happens to the signal as you 
> turn the dial on the RIG.
> 
> Rich,
> KE0X
> 
> 
> -- 
> View this message in context: 
> http://www.nabble.com/K3-Firmware-2.10%2C1.81-problems-Update-
tp18154703p18163577.html
Sent from the Elecraft mailing list archive at Nabble.com.

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