Vega U2020 Application Manual

U2020

Application Guide

Vega U2020 Application Guide

This guide provides information for configuring U2020 systems with various numbers of channels. Block diagrams
and basic equipment lists are provided for systems with from four to sixteen channels. Other useful application and
configura t ion information is also included.

Important Notes

1. Each MC-2020 series multicoupler can power to up to four attached receivers through its BNC antenna cables.
The MC-2020 power supply has a capacity of 2.5 amperes, more than enough for four receivers and the
multicoupler itself. It is NOT necessary to use the wall-type power supplies for the receivers when they are
connected to the output of a MC-2020 multicoupler. This usually considerably simplifies the installation of a
U2020 system.

WARNING

Because dc power is present at the output connectors of the MC-2020, unused outputs SHOULD NOT be
terminated with 50 ohms. For the same reason, MC-2020 series mulitcouplers SHOULD NOT be used with

receivers other than the R-2020. Serious damage to the receiver, and in some cases to the multicoupler, can
result.

2. The original MC-2020 multicoupler covered the 746 -782 MHz frequency range used by the "A" and "B"
versions of the U2020 system. The newer MC-2020A multicoupler covers the full 672 to 782 MHz frequency
range, making it compatible with the newer "C", "D", "E" and "F" frequency ranges for the U2020, as well as
with the original "A" and "B" ranges. If a U2020 installation includes ANY systems in the newer "C", "D", "E"
and "F" frequency ranges, the MC-2020A multicoupler MUST be used, and not the original MC-2020.

3. Early MC-2020 multicouplers used 2.5 mm power connectors, the same size as for the R-2020 receiver. In some
instances, users attempted to power MC-2020s and the attached R-2020s from one of the small wall-type power
supplies. This resulted in system failure and overheating of the power supply. Recently produced MC-2020s and
all MC-2020As use a 2.1 mm power connector, preventing this problem.

If a replacement power supply is required for a MC-2020; please specify the connector size when ordering. (If
the plug on a wall-type power supply fits the power connector on the MC-2020, a replacement with the 2.5 mm
connector is required. If it does not fit, a 2.1 mm power connector is needed.)

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Vega U2020 Application Guide

Application Tips

The MC-2020 and MC-2020A are supplied with eight 24" (60 cm) BNC RF cables for connecting the multicoupler
output to four R-2020 receivers. Unless remote antennas will be used, no additional RF cables will be required.

The MC-2020 and MC-2020A are not supplied with antennas. Generally, installations that use multicouplers will
require remote antennas. If the use of whip antennas is acceptable, the whips supplied with one of the R-2020s can be
used. Note that the antennas can be converted from right-angle to straight whips by loosening the hex set screw on the
side of the antenna body, removing the antenna element, reinserting it into the hole on the end of the body, then
retightening the set screw.

The R-2020 receiver and MC-2020 series multicouplers include a feature that allows the antennas to be mounted on
either the front or the rear of the unit. These units are normally shipped with the connectors on the rear panel. If
relocation to the front panel is desired (to permit use of the supplied whip antennas when the eq uipment is rack
mounted, for example), proceed as follows.

To move antennas to the front of the multicoupler

1. Remove the screws attaching the bottom cover of the unit and detach the cover.

2. With a 5/8" (16 mm) socket wrench, remove the hex nuts attaching the connector to the multicoupler rear

panel.

3. Gently push out the round plastic cover hole covers on the front panel of the unit.

4. Remove the antenna connectors from the rear panel of the unit and install them in the front panel of the unit.

Make certain that the internal antenna cables do not lie down directly on the multicoupler circuitry, as this
will affect performance.

5. Reinstall the connector hex nut and lockwasher, then gently tighten the nut. Do not use excessive force, as

this can crack the panel of the unit.

6. Repeat for the other connector.

7. Push round plastic cover hole covers into the hole where the antennas were before and reinstall the bottom

cover of the unit.

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Vega U2020 Application Guide

To move antennas to the front of the receiver

1. Using a Phillips-head screwdriver, remove the two bottom screws (bottom panel closest to the front of the
receiver) and the two screws on the rear panel as shown below.

2. Using a 5/8” (16 mm) socket wrench, unscrew the antenna hex nuts. Then using a small pair of pliers, gently
unscrew the round serrated audio-output connector nut.

3. Gently slide the PCB out.

4. Pop out the antenna plugs in the front of the receiver.

5. Carefully move the antenna connectors to the front panel and insert the connectors through the holes. Make
certain that the internal antenna cables do not lie down directly on the receiver circuitry, as this will affect
performance.

6. Screw the hex nuts and lock washers back on (being careful not to use excessive force) and slide the PCB back
into the case. Then reattach the two bottom screws.

7. Pop the plugs into the antenna holes in the rear panel and reattach the audio-output nut and small screws to the
rear panel.

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