MFJ-269C-Pro Instruction Manual LF/HF/VHF/UHF SWR Analyzer
9
Important Note:
Section-4 of this manual provides detailed instructions for using each of the five basic
operating modes described above. To ensure accurate measurement and avoid the possibility of
inadvertent damage, please read through this section carefully before operating the analyzer!
3.4 Frequency
Control
The MFJ-269C-Pro tunable RF-oscillator covers an exceptionally wide frequency span, using two rotary
band switches for
LF/HF/VHF
coverage (.53-230 MHz) -- plus an additional pushbutton switch to
activate
UHF
coverage (415-520 MHz) .
155-230
113-155
67-113
28-67
11-28
4.7-11
2.1-4.7 1.0-2.1
0.53-1.0
Lower
Range
TUNE
FREQUENCY MHz
UHF
ON
OFF
UHF HI
UHF LO
1. LF, HF and VHF Operation:
The
Lower Range
rotary switch selects four LF and HF bands (0.53-
11.0 MHz). The
Upper Range
switch selects 5 HF and VHF bands for 11-230 MHz coverage. Note that
the
Upper Range
switch must be set
fully clockwise
to the
Lower Range
position for the lower-range
band selector to function. The variable
Tune
control (VFO capacitor) provides a small overlap at each
band edge to ensure gap-free tuning across the spectrum.
*Note
that LF coverage may be lowered to
0.470-0.940 MHz
(or lower) for 600-Meters and select
maritime services. To modify, (1.) adjust
Tune
fully counter-clockwise, (2.) remove the back cover (3.)
Remove battery pack by removing Philips head screws and, (4.) using a 2-mm hex tuning wand, readjust
inductor
L12
while watching the frequency display.
2. UHF Operation:
UHF coverage is broken into two bands. To measure
UHF
SWR (415-520 MHz),
first press in the
UHF
switch located just above the LCD display. Then, for
415-470 MHz
coverage, set
the upper
Frequency MHz
switch to the
113-155 MHz
band (
UHF LO
). For
470-520 MHz
coverage,
set the upper
Frequency MHz
switch to
155-230 MHz
.
(UHF HI).
It is normal for the VFO's
Tune
range to exceed the analyzer's usable
UHF
measurement range. If the
VFO frequency is out of range in UHF Mode, one of the error messages shown below will instruct you to
increase or decrease frequency to bring it back in range:
Adjust
Tune
clockwise
to
increase frequency
and
counterclockwise
to
decrease frequency
. When in
range, the operating
Frequency
will appear on the top line of the LCD display -- along with the
SWR
reading. The bottom display line becomes an analog
SWR bar-graph
(see below).
445.75 MHz 1.3
INCREASE
FREQUENCY
DECREASE
FREQUENCY