FSK RTTY operation

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  • Updated 5 years ago
When will FSK mode be added? I know the accy connector has FSK keying provisions but there is now FSK mode option. Will there be adjustable dual peak filters for the mark and space?
Photo of Greg


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Posted 6 years ago

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Photo of Andrew O'Brien

Andrew O'Brien

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Any update on this question ?
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Pat - WH6HI

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This just an opinion, in that with modes like RTTY, PSK and other text modes, there will be the need for new code written to engage a new window with it's on commands and I/O for the keyboard.  I have a feeling that this may be in Rev. 2 territory, so we will not see it until Rev. 1 is full developed.  I think that we are close to that point in that 1.4 is doing very well. 

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Why is FSK required?   I am very curious.  I used to insist on FSK back in the day but now with FlDigi (or other such app) and digital audio channels (DaX) I can't think of a compelling reason. 

aFSK via DaX is working like a charm at this (6500) station.  Having studied over the signal generation methods and using both for years,  FSK / aFSK should be identical at the receiving end.

Main Concerns:

overdrive - This is an operator error, not a system signalling limitation.
switching tones when not at a zero crossing - I would hope the RTTY / digital apps switch tone frequencies only on the zero crossings.  

logging the actual frequency -  this is in the domain of the software and not a systems | signaling issue. Should be readily addressed


Someone (Grant?) posted a compelling argument for FSK and contesting. Staying put on a calling frequency with the AFC modes of FlDigi, ones moves around a bit  off frequency due to AFC-tracking calling stations.  Now that two independent slices are useable, one for xmt the other rcv, (FlDigi for example) this concern should be addressed.

To implement FSK I would assume this is will driven by a waveform file.  Similar to FeeDV with the caveat the FSK h/w internally being enabled.

If one is running 170 cycle shift and turn on the brick wall filters at 200 cycles with that eliminates a lot of adjacent channel signals.  Be that as it may, under severely crowded conditions (RTTY RU) the 6500 and FlDigi didn't have any problems with signals right next to those being decoded.
A 200 cycle filter with a TNF set at the center and wide enough (~100 cycles) would take out all but the frequencies of interest.

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I hope RTTY is not that far back on the burner.  There are plenty of RTTY contests and to jump through the hoops I do now to operate makes it not impossible, but like taking a sip of cold, bitter coffee.  I hope the work in V1.5 on DSP will make it easier getting the RTTY functionality up to par with other radios in these current price ranges.  

I don't expect RTTY to be at the top of the feature list, but since it is used for contesting and a number of DXpeditions, I would like to see it sooner rather than a year or two away.

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jim WB5AAA

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hope they get around  FSK RTTY    in rev 1.4.1