As the mode is coded with a TX and RX centre frequency of 8962.5 Hz , the PC becomes a software defined stand alone ?radio?
To accommodate the
use of class e/d amplifiers with ?divide by 2? function in the drive chain, the tx toned may be switched to 16 Khz with X2 deviation , which after amplification, reverts to the 8 K parameters
Notably
this is a live data mode (as all ros modes) so
there is no requirement for accurate PC
time setting and offers a
wide ?AFC? range of 78 Hz negating the need for high initial frequency stability or ?net? the system is tolerant of upto 5 Hz drift after initial lock
Notes for its
installation / use are posted along with the zip exe file,
Note - you will need to
have the normal HF/MF version installed and working , before the vlf exe will run
Obviously Ros-vlf cannot bend the laws of physics and is a live keyboard data mode with 0.4 baud rate , so signal levels will need to
be higher than those required for slow time base ?trace? observations , however from initial tests , it is functioning well below audible levels .. Its advisable to observe the mode working at HF at the higher baud rates to gain a overview of its operation.
https://sites.google.com/site/uk500khz/ros-vlf---exe
Data summery
Frequency tx/rx
8950-8975 Hz
Bandwidth
25 Hz
Baud rate
fixed 0.4 / (0.8 not posted)
Rx
AFC range
78 Hz
Drift
tolerance
5 Hz
S/N 0.4 Baud
-38 dB
73 - G ..G0NBD