[Elecraft] K4 Use Case Question - Support for multiple instances of WSJT-X

[David Gilbert]

Other than being able to monitor two different bands (or two different 
sections on the same band) I'm not sure what the benefit here is, but I 
wonder if I could accomplish the same thing with my K3.

1.  Run two instances of WSJT-X
2.  Use two different USB sound card dongles, each port assigned to one 
of the WSJT-X instances
3.  Use left ear/right ear audio output from the two K3 VFOs, left ear 
to one USB sound card and right ear to the other
4.  Use "Fake it" instead of "Rig" split control

I don't see that there's any gain in contact efficiency here, though.  
The transmissions for two different QSOs would have to alternate, and 
the odds of getting out of sync with the guy on the other end would be 
significant.  If you were actually making a lot contacts from both VFOs 
this way you'd be disrupting a lot of sequences, and if everyone else 
was doing this it would be total chaos.

So I'll ask again ... what am I missing here?

73,
Dave  AB7E


On 8/20/2019 8:27 AM, Wayne Burdick wrote:
> This will work with either a K4 or a K4D. The VFOs can be on the same or different bands.
>
> If the two receivers were on different bands, and you only had one antenna, you'd want to make VFO A the higher-frequency band. This is because with a single antenna, both receivers would be sharing the transmit signal path, which includes low-pass filters.
>
> Suppose VFO A is on 20 meters and VFO B is on 40 meters. Both are subject to the 20 meter low-pass filter, so both will have full sensitivity. Now you want to work a station heard on 40 meters (VFO B/sub). Since you need the 40 meter low-pass filter for transmit, you'd the controlling computer would need to swap VFOs (or you could do this manually by tapping A/B).
>
> * * *
>
> Notes:
>
> - If you had a separate receiving antenna usable on multiple bands, then the low-pass filter constraint goes away; either VFO could be on any band. You'd still need to swap VFOs to transmit on the VFO B band, then swap back.
>
> - If you had a K4D, then each receiver would have its own set of bandpass filters, which may be helpful in high-signal conditions. They could also use different antennas.
>
> - It may even be possible to run WSJT on the K4 itself, though I can't put a date on this. Some porting required :)
>
> 73,
> Wayne
> N6KR
>
>
>
>> On Aug 19, 2019, at 11:06 PM, Logan R Zintsmaster <lrahnz at garlic.com> wrote:
>>
>> Here is a use case question..
>>
>> The radio is connected to a single antenna.
>>
>> VFO A is tuned to 14.074 MHz and VFO B is tuned to 14.080.
>>
>> An audio data stream from the VFO A frequency is "connected" to an instance
>> of WSJT-X decoding FT8.
>>
>> A second, independent audio stream from the VFO B frequency is concurrently
>> "connected" to a second instance of WSJT-X decoding FT4.
>>
>> Both instances of WSJT-X decode their respective audio streams,
>> concurrently.
>>
>> Starting a QSO in either instance of WSJT-X switches the transmitter to the
>> appropriate VFO for the duration of the QSO.
>>
>> The audio stream for the instance of WSJT-X not in the QSO is interrupted
>> while the transmitter is operating.
>>
>>
>>
>> Can a K4 support this use case or is a K4D required?
>>
>> Can this use case be supported if each instance of WSJT-X is in a different
>> band?
>>
>>
>>
>> 73
>>
>> Logan, KE7AZ
>>
>>
>>
>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to n6kr at elecraft.com
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to xdavid at cis-broadband.com
>