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Spectrum Management - From the Early Years to the 1990s
by Laval Desbiens
Page 23 of 26
Measuring Frequencies with the Racal RA17C12
Frequency
standard
Output
1 MHz standard input
100 kHz
IF out
to x
2nd VFO out
to the mixer
When the fine tuning is adjusted so that a 1:1 Lissajous pattern appears on the scope, the receiver is tuned exactly to the incoming frequency.
1 MHz
Example a) -
3.780123
b) -
43.500000
c) -
1 out
39.719877
d) -
37.500000
e) -
2.219877
f) -
2.319877
Last IF g) -
0.100000
At mixer output, there is a difference of 5.1 MHz minus f) of which only the significant,
or last six (6) digits are retained, since the "MHz" are read directly on the receiver.
2.780123
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