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
