Bruker DAEDALUS, Service Manual

Page: 57 / 145

Chapter
Daedalus Lock Manual Spectrospin AG 51
19F TX Option 6
Function Description 6.1
General 6.1.1
If Fluorine (19F) is used as lock substance, the normal Deuterium lock frequency
must be shifted to 19F frequency. This is done in a mixer, which uses a local oscilla-
tor signal (f
pll
) and the normal Deuterium signal (f
2H
) as inputs and creates the 19F
frequency (f
19F
) as output.
This mixing process is performed on the 19F TX Option board. The board also pro-
vides the local oscillator signal for the inverse mixing process on the 19F RX Op-
tion board, where the Fluorine frequency is shifted back to Deuterium in order to
use the normal Deuterium lock receiver path.
19F TX Option Block Diagram 6.1.2
The block diagram of the lock transmitter gives information about the environment
of the 19F TX Option (see the lock transmitter section in this manual). A detailed
block diagram of the 19F TX Option is shown in the following figure:
Figure 10: 19F TX Option Block Diagram
f
19F
f
pll
f
2H
+ =
Mixer
LP
HP
VCO 1/M
1/N
φ
Loop Filter
Amp
Amp
HP
Amp
f
ref
10MHz_BUF
f
2H
19F_LO
19F_TR
f
19F
LP
TP
19F_OPT
f
pll
Attenuator