Hi all
I think Stefan is going to direct key the TX ON/OFF from the Serial
Port or he is doing it from a PIC type keyer (like me) or he has just
recorded the output from the PC SC onto an MP3 player and using the ON/OFF
tone on a continuous loop to key a relay transistor via a sound
detector cct thence to key the TX. All options are possible this is the good
bit about this type of weak signal communication.
The RX window is 1.6 / 1.8kc/s from the TX carrier on an SSB TX
(Upper Side Band) but when using a CW rig the carrier has to be with in the
window on the EU 600m band it is currently 478.6 / 478.8kc/s on the UK
600m band it is currently 501.6 / 501.8kc/s.
So long as the RX is set such that it hears a tone 1.6 to 1.7kc/s
and that it is connected to the PC Sound Card input at the right level then it
will decode. So if you use a Direct Convertion RX it
doesn't matter which way you approach the signal either upper or lower side
band.
73 es GL Pete M0FMT IO91UX
Stefan,
Download the Opera
program. In the waterfall you will see two red lines, put the cursor on the
lines and read the frequency (upper left window of the waterfall
display) Op4 differs from Op8 etc a frequency within this band is the
input of the USB TX so 477kHz + (a frequency between the red lines). When
using CAT control Opera will choose a not occupied freq. in the appropriate
pass band.
73,
Albert
