Windows does not offer 'channel presets', so you should specify an absolute UHF channel in the range 21 to 69; and other values will be faulted.
It is with apologies to European viewers that WinTTX does not specifically support frequencies outside of the 21-69 range. To be honest, I am not certain if the tuner is physically capable of receiving such frequencies.
If you are Belgian and you are willing to give this a try, WinTTX (v1.50) will accept three special channels as follows:
|75||175.25MHz||Corresponds to La Une in Dinant / Houffalize / Malmedy|
|89||189.25MHz||Corresponds to La Une in Bruxelles|
|96||196.25MHz||Corresponds to La Une in Wavre|
Why Belgium? Because RTBF Sat teletext listed the frequencies.
Why is there no sound in Europe?
If you connect a lead to the Aux port (audio/video output), you will not hear any sound in Europe using a Ground Control/Octopus receiver (and probably not with others, either). This is because the UK uses PAL I where the sound carrier is +6MHz from the tuned channel; however Europe uses PAL B/G where the sound carrier is only +5.5MHz. A good television engineer may be able to rectify this by altering something inside your tuner.