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As shipped from the factory, a 1-kHz receiver signal with standard deviation gives Π10 dBm on the
line, but this can be varied by VR4002 and S4001 (on the repeater' s CNTL Unit).
Pins 7 & 8 [TX KEY (+), TX KEY (-)]
An opto-isolator is provided to facilitate M (MIC) signaling. That is, a voltage presented to these
pins turns on the opto-isolator and keys the transmitter.
The TX KEY (+) pin is the anode of the opto-isolator, and RX SQ(Π) is the cathode of the opto-
isolator.
Installation
Antenna Considerations
Repeater operation without a duplexer requires that two antennas be installed, one for receiving and
one for transmitting, so that the receiving antenna does not absorb energy from the transmitting
antenna. There are a number of ways to do this, depending on the TX/RX frequency separation, and
on the locations available for antenna mounting. If a duplexer is used, a single antenna suffices for
both transmitting and receiving. If using a reduced-size duplexer, a six-cavity model (minimum) is
recommended. Vertex Standard recommends the use of the duplexer. For further details, contact your
Vertex Standard dealer.
Regardless of the above choice, it is of paramount importance that the antenna(s) be mounted as high
and in the clear as possible, preferably within line-of-sight to all repeater users. Furthermore, losses
in the feedline(s) must be minimized, so the feedline(s) should be high quality, and as short as
possible. If a long feedline is necessary, use coaxial "hardline", cable to reduce losses.
Repeater antennas should have impedance of 50 ohms at the operating frequency. When separate
receives and transmits antennas are used, high-Q narrow-band types may serve to minimize
interaction. However, when a single antenna is used with a duplexer, it should be a low-Q wide-band
type.
NEVER TRANSMIT WITHOUT HAVING A
TRANSMIT ANTENNA CONNECTED TO
THE
TX
ANTENNA
REPEATER.
AC Power Supply Voltage Selection
Each repeater is wired for a particular AC mains voltage between 100 and 253 VAC. This should be
indicated by a label near the AC jack on the rear panel. If no label is present, or if the AC voltage on
the label is different from the local AC line, check the wiring inside the Switching Regulator Unit of
the repeater, and change the connections (and label) if necessary, as shown next page.
Changing the AC input voltage wiring also requires changing the fuse on the FILTER Unit if the
voltage is changed from 100 VAC (100-127 VAC) to 200 VAC (207-253 VAC), or vice-versa. Use a
5-amp fuse for 100 VAC, or a 3-amp fuse for the 200 VAC.
DC Power Supply Backup
For uninterrupted operation during power failures, a 12-volt rechargeable type battery (55-Ah or
more recommended) may be connected to the BATT terminal posts on the rear panel. While the
repeater is operating from the AC source, a slight charging current will maintain battery charge. In
JACK
OF
THE
VXR-7000U FM
REPEATER OPERATING MANUAL
6
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