DX Engineering DXE-DMC-2 User manual

Dual Module Chassis
DXE-DMC-2
DXE-DMC-2-INS Revision 1a
© DX Engineering 2020
1200 Southeast Ave. - Tallmadge, OH 44278 USA
Phone: [phone] ∙ Tech Support and International: [phone]
Fax: [phone] ∙ E-mail: [email protected]

2
Introduction
The DX Engineering Dual Module Chassis (DXE-DMC-2) is the connector and power interface
box for all DX Engineering Plug-In Modules and Receive Filters. This is one of the most highly
requested DX Engineering accessories. You can build a special HF receive filter or create a wide
pass filter, protect a receiver with a filter and a limiter or make a preamplifier with filtering or
limiter protection.
Features of the DXE-DMC-2 Dual Module Chassis:
Attractive black aluminum enclosure
Green LED for Power On indication
Two internal option slots for Plug-In Modules
Receive Antenna Input, Receiver Output –BNC for 50 ohm and F connector for 75 ohm
feedlines (use 75 to 50 ohm Impedance Transformer Plug-In Module - DXE-IT-PM)
Internal jumper to enable bias-tee DC power injection onto receive feedline for active
preamplifier plug-in option
Screw-on version of the DC power connector is provided to prevent accidental power cable
pull-out (standard type 2.1 mm DC power connector may be used)
Operates on +13.8 Vdc nominal
.

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To open the unit, remove the 6 Phillips head screws to open the unit. Remove the cover. You will
then see the main PCB and the by-pass module installed.
The DXE-DMC-2 is a versatile multi-purpose DX Engineering receive device box. It can be used
for two passive plug-in modules or one powered module and one passive module. The top slot is
first in line from the Antenna Input, paralleled BNC and F connectors.
Next in line is the bottom slot that feeds the two parallel Receiver Output connectors, F and BNC.
This position has voltage available for an active plug-in module such as the DXE-RPA-2-PM
Receive Preamplifier Plug-in Module.
One bypass card is supplied to install in either unused slot when only
one module is used.
Available passive modules include the limiter, the transformer and many types of filters. The
preamplifiers are powered modules.
When used, a preamplifier plug-in module is typically powered by a + 13.8
Vdc station supply using the supplied 2.1 mm screw-on connector or a
standard 2.1 mm connector. Turning off the power bypasses the received
signal around the preamplifier module, allowing reception without pre-
amplification.
Alternatively, if the DXE-DMC-2 unit is used as a weather-
protected remote preamplifier, an internal jumper change
enables the preamp module to be powered by an in-shack
voltage inserter on the DXE-DMC-2 Receiver Output
feedline.
Note: There is no Bias-Tee available to the Antenna Input for
active antennas with his unit.

4
Installing Optional Plug-In Modules
DX Engineering optional modules used with the Dual Module Chassis:
Part Number
Description
DXE-IT-PM
75 to 50 ohm Impedance Transformer Plug-in Module (passive)
DXE-RG5000HD-PM
Receiver Guard 5000HD Plug-in Module (passive)
DXE-RPA-2-PM
Receive Preamplifier Plug-in Module (powered)
DXE-RXFL-1
Receive Filter Adapter Board, for RXFL Filters (passive)
DXE-IT-PM DXE-RG5000HD-PM DXE-RPA-2PM
Open the unit by removing the 6 Phillips head screws and
remove the cover.
The picture shows the cover removed and two optional
plug-n boards ready to install.
Remove the by-pass jumper PCB in the bottom slot by gently using a straight shaft screwdriver on
each side of the PCB. Pull one side loose, then the other side as shown below.

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This example shows installing the optional DXE-RG5000HD-PM plug-in module. Place the board
on the pins and push the PCB until it fully seats in place.
The optional filter board needs to be installed on the DXE-RXFL-1 Receive Filter Adapter Board.
Install your optional filter board by pressing it filly in place on the Adapter Board. Insure you have
the pins properly aligned as shown.
The optional Filter Board and Adapter board are then installed in the DMC-2 by aligning the board
pins an pressing evenly until the board is fully seated in place.
Optional Filters, the DXE-RG5000HD-PM and DXE-IT-PM can be installed in either slot.
If you are installing the optional DXE-RPA-2PM preamplifier, it must be installed in the bottom
slot. The bottom slot has DC power available. The top slot does not have DC power available.
If a slot is not used, the jumper PCB should be installed.

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One optional DXE-RXFL-1 Receive Filter Adapter Board is required to
install any one of the optional RXFL filters listed below. They are used in the
DXE-DMC-2, DXE-NCC-2, DXE-RTR-2 and DXE-RPA-2.
The DXE-DMC-2 can accommodate one or two filters to create the filter
type and input signal band pass frequency coverage and limitations that serves your needs. Filter
roll-off frequency is the point where attenuation begins to increase typically to over than 50 dB.
Receive filters are excellent reception improvement tools. They reduce most of the interfering noise
and signals on the attenuated frequencies from entering the front end of the receiver. Reducing the
noise floor of the receiver allows better reception on desired frequencies.
Filter Part Number
Description
DXE-RXFL-HP160M
High Pass Filter, Roll-Off below 1.8 MHz
DXE-RXFL-HP80M
High Pass Filter, Roll-Off below 3.5 MHz
DXE-RXFL-HP40M
High Pass Filter, Roll-Off below 7.0 MHz
DXE-RXFL-HP20M
High Pass Filter, Roll-Off below 14.0 MHz
DXE-RXFL-HP15M
High Pass Filter, Roll-Off below 21.0 MHz
DXE-RXFL-HP10M
High Pass Filter, Roll-Off below 28.0 MHz
DXE-RXFL-LP160M
Low Pass Filter , Roll-Off above 2.0 MHz
DXE-RXFL-LP80M
Low Pass Filter , Roll-Off above 4.0 MHz
DXE-RXFL-LP40M
Low Pass Filter , Roll-Off above 7.3 MHz
DXE-RXFL-LP20M
Low Pass Filter , Roll-Off above 14.4 MHz
DXE-RXFL-LP15M
Low Pass Filter , Roll-Off above 21.5 MHz
DXE-RXFL-LP10M
Low Pass Filter , Roll-Off above 29.7 MHz
DXE-RXFL-BPF160M
Band Pass Filter, Roll-Off below 1.8 MHz and above 2.0 MHz
DXE-RXFL-BPF80M
Band Pass Filter, Roll-Off below 3.5 MHz and above 4.0 MHz
DXE-RXFL-BPF40M
Band Pass Filter, Roll-Off below 7.0 MHz and above 7.3 MHz
DXE-RXFL-BPF20M
Band Pass Filter, Roll-Off below 14.0 MHz and above 14.4 MHz
DXE-RXFL-BPF15M
Band Pass Filter, Roll-Off below 21.0 MHz and above 21.5 MHz
DXE-RXFL-BPF10M
Band Pass Filter, Roll-Off below 28.0 MHz and above 29.7 MHz

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Filter Graphs
The following 18 charts show the response curves for the 18 optional filters that are available for
the DXE-DMC-2.
DXE-RFXL-LP160M - Low Pass, 160 M and below - Cut off Frequency 2.30 MHz
DXE-RFXL-LP80M - Low Pass, 80 M and below - Cut off Frequency 4.00 MHz

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DXE-RFXL-LP40M - Low Pass, 40 M and below - Cut off Frequency 7.50 MHz
DXE-RFXL-LP20M - Low Pass, 20 M and below - Cut off Frequency 15.00 MHz

9
DXE-RFXL-LP15M - Low Pass, 15 M and below - Cut off Frequency 22.00 MHz
DXE-RFXL-LP10M - Low Pass, 10 M and below - Cut off Frequency 30.00 MHz

10
DXE-RFXL-HP160M - High Pass, 160 M and above - Cut off Frequency 1.65 MHz
DXE-RFXL-HP80M - High Pass, 80 M and above - Cut off Frequency 3.40 MHz