/Built/L23HP.doc
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12/27/2017
installed) when the Mast Mount LNA switching option is ordered. The fused line is directly
connected to the step 1 output. Re-install the two screws. From the output of the Fuse, the DC
power can be routed to a switch mounted on the front panel of the transverter and then to the Pin 1
of the AUX connector or to the LNAB connection on the circuit board near C2 if the mast mount
LNA requires bias on the coax. A choke is installed between the LNAB connection and the RFRX
transmission line acting as a Bias “T”. Then the bias to the LNA is then sequenced or switch out of
line (with the front panel switch) if it is desired to bypass it. See the Components List for the
optional Choke value.
CAUTION:
Remove L2 from the circuit or the fuse will blow instantly. The
LNAB choke may be repositioned if a separate RFRX port is used. An Auxiliary instruction sheet
for installing DC power on the coax is attached at the end of this document.
Relative Power Meter:
The bar graph display is a relative power meter and is driven by the
directional coupler and RF detector circuit found in the Low pass filter section of the board (CR2,
R1,R2,C1) RF is detected and converted to DC voltage and conducted to the Bar graph display on
the front panel. If you find that you operate the transverter at any other level than what we have
calibrated it to 25 watts = 9 bars, you may change it by adjusting VR1 on the display board. It is
located under the Digilo. You may also send the detected voltage out through the AUX connector.
Select an unused pin and make the connection.
Synthesizer Frequency Change:
This is the newest option available. You may select at any
time, any desired IF operating frequency from the list of available frequencies. Just short the two
pads marked with the indicated number specified below with a simple solder connection. The
DIGILO is marked “0-7 Frequency Select”. The selections are listed below.
Frequency of Operation
Short pins
1296 = 28
3
1296 = 29
1,3,4,6,7
1296 = 50
0,3,4,6,7
1296 =52
3,4,6,7
1296 = 144
0,1,2
