Locked Re: FT8 F/H TS850 settings

Bill Somerville

On 06/02/2020 22:56, F6DKQ wrote:
Hi all,

Can someone tell me how to set my TS850 with wsjtx in F/H mode.
I use a signallink interface and a cat cable (rs-232) to my computer
Apparently the "rig" setting for the split does not work. Should I use the "fake-it" setting ?

It seems to work so, I made a few qso's, but the erratic shifts of the VFO alwas frighten me
If the DX is on DF 539, and I'm calling on DF 1600 for instance, my VFO shifts by one Khz and my tx is right on 539 when I reply
I suppose it's normal, since I get a RR73...?
73, Guy F6DKQ

Hi Guy,

the VFO dial frequency changes should not be erratic. The VFO dial frequency is shifted during transmissions, such that the Tx audio can be maintained between 1500 Hz and 1999 Hz, this is done to keep the audio within the bandwidth of your SSB Tx filter, thus avoiding unwanted attenuation. The Rx VFO dial frequency remains unchanged. Shifting the Tx VFO dial frequency also has the benefit of attenuating any audio harmonics as they will always occur above 3000 Hz and be above the low pass cut off of your Tx SSB filter. Tx VFO dial shifts are calculated in 500 Hz steps, e.g. with an Rx frequency of 14074.0 kHz here are some examples:

Tx audio offset      Tx VFO QRG   Audio sent to rig
---------------      ----------   -----------------
            200         14072.5                1700
            499         14072.5                1999
            500         14073.0                1500
            999         14073.0                1999
           1200         14073.5                1700
           1700         14074.0                1700
           2100         14074.5                1600
           2700         14075.0                1700
           3250         14075.5                1750
           3700         14076.0                1700
           4400         14076.5                1900

and so on.

Using "Settings->Radio->Split Operating->Rig" should be your first option, only try "Fake It" if the rig does not support SPLIT or if some other problem occurs. When using a SignaLink USB, which keys the rig independently, you should normally select "Settings->Radio->PTT Method->VOX" as WSJT-X should not be keying the rig directly. To minimize the uncertainty of exact timing of the transitions between Rx and Tx it is best to turn the SignaLink USB DELAY knob to minimum. This will often improve the reliability CAT control when combined with a SignaLink USB interface for audio and PTT.


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