Pyramid Communications VR-100 User Manual

15182 Triton Lane #102 Huntington Beach CA 92649

VR-100

Vehicular
Repeater

Revision D Aug 25 1994

VR-100

Table of Contents

Specifications ..................................................................................... 1

Introduction ........................................................................................ 2

Functional Description ....................................................................... 3

Trunking Operation ........................................................................... 4

Installation .......................................................................................... 5

Jumper Selection ................................................................................ 5

Radio Connections ............................................................................. 6

Alignment ........................................................................................... 8

RF Alignment ..................................................................................... 8

Repeater Alignment ........................................................................... 9

CTCSS Table .................................................................................... 10

Figure 1 RF Test Points ................................................................... 11

Crystals ............................................................................................. 11

Figure 2 VR-100 Parts Locator ........................................................ 12

Parts List ........................................................................................... 13

Schematic .........................................................................

Fold Out

VR-100

Specifications

General:

Operation: Motorola PAC/RT® compatible plus trunking.
Modes: Priority, non-priority disabled, test mode.
Indicators: 8 high brightness LEDs, handheld queueing tones.
Interface: 9 pin "D" connector with 6 ft. cable.
Adjustments: Receive sensitivity, transmit dev., squelch threshold,

local mic sens., lock tone decode frequency, lock
tone dev., local speaker audio.

Jumpers: COR polarity, on-air polarity, enable/disable polarity,

Tx audio flat/de-emph., Rx audio flat/pre-emph.

CTCSS: DIP switch selectable, 37 EIA tones + 69.3 & 97.4

Power Requirements:

DC supply: 13.6 VDC ±25% negative ground.
Standby: 80 mA.
Receive: 250 mA.
Transmit: 1.5 A.

Physical:

Dimensions: 5.275"W x 6"L x 1.12"H.
Weight: 18 oz.
Case: One piece extruded aluminium.

Transmitter:

Frequency Range: 450-470 MHz
RF Power: 0.25-2W adjustable
Tx Spurious: -50dbc
Stability: 5ppm
FM Noise: -55db
Audio dist: <5%
Tx sens: 50mV-2.5V RMS
Lock Tone: Jumper selectable: 832.5 or 847.5Hz
FCC TA: LRUVR-100U Parts 22, 90

Receiver:

Frequency Range: 450-470 MHz
Sensitivity: .4μV for 12db Sinad
Mod Acceptance: ±7.5kHz
Selectivity: 70db
Spurious/image rej.: 60db
IMD response: 65db
Stability: 5ppm
Lock Tone detect: Tunable: 820 Hz to 930 Hz, 1% bandwidth
Local Rx Audio: 400mW into 8 Ohms

Specifications Subject to Change without notification

Page 1

VR-100

Introduction

The Pyramid Communications model VR-100 is a microprocessor
controlled low power vehicular repeater. It is designed to interface
between a high power mobile radio and a low power UHF handheld. If
the radio operator is out of the vehicle and the mobile radio is receiving
a transmission, the VR-100 will repeat the signal to the users handheld.
The user may also transmit back to the VR-100 via the handheld, and their
transmission will be repeated back to the base by the high power mobile
radio, effectively extending the range of the low power handheld.
On-board logic control by the microprocessor ensures that only one
vehicle will become active as the repeater, should several vehicles arrive
at the same scene. The logic also handles cases where the priority vehicle
leaves the scene (or fails), or another priority vehicle arrives from a
different site.

The model VR-100 is fully compatible with Motorola PAC/RT®
systems, as well as GE Ericsson and Standard EX-10/ CTS-20 radios.
Additionally, the VR-100 supports connection to LTR® or Motorola
trunking radios, local mic audio repeat (local PTT from the mobile is
repeated to the HT's), and local speaker audio for HT-Base transmissions.

Designed to interface to a wide variety of mobile radios, the VR-100
has input and output adjustments for Rx audio sensitivity, mobile Tx
deviation, COR polarity and threshold, local mic sensitivity, local speaker
audio, on-air detect polarity, enable/disable polarity and audio response
selections for flat or 6db/octave for both Tx and Rx audio paths. There
are also jumper selections for lock tone frequency, priority sample rate,
conventional/trunking operation and a built in test mode.

The eight LED front panel status indicators confirm proper CPU
operation, priority status, and mobile/repeater COR and PTT status.

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VR-100

Functional Description

The VR-100 operates on UHF simplex frequencies; the handhelds
transmit CTCSS but are carrier squelch receive. The VR-100 has CTCSS
on receive only. The repeater should be connected to a VHF high band
or low band mobile for best operation. Connection to a UHF mobile is
possible, provided there is enough separation in the mobile transmit and
the VR-100 receive frequencies. Also, antennas for the VR-100 and the
mobile radio should be located as far apart as practical, and with vertical
separation if possible. Additionally, bandpass filters and notch cavities
may be used to reduce interference between the mobile and VR-100.

When the user leaves the vehicle, they activate the VR-100 via their
mobile radio front panel or a separate switch. When the mobile radio is
receiving carrier and proper tone, the VR-100 will begin transmitting on
the handheld's receive frequency. The user is able to hear and respond to
all radio traffic, including other handhelds at the site. The VR-100 will
cease transmission periodically to check for handheld activity. If the VR­100 detects proper carrier and tone from a handheld, it will key the mobile
radio and repeat the users transmission. In this way, the handheld is given
priority and may respond during repeater hang time. The VR-100 has a
3 minute time-out timer in the base to handheld direction. If the base
transmits to the mobile for more than 3 minutes, the VR-100 will send an
error tone to the handheld, unkey the repeater and remain idle until the
base ceases transmissions.

When the VR-100 is first activated, it will transmit a short "lock tone"
that alerts the user that the system is functioning. It will then assume the
priority status and be ready to repeat any base to handheld or handheld to
base transmissions. If another unit arrives at the same site and is
activated, it too will transmit the "lock tone"; when the first VR-100
detects the lock tone from the second unit, it will increment it's priority
counter and will no longer repeat any transmissions. This process will
continue for each unit that arrives at the scene, creating a priority
hierarchy for up to 256 vehicles.

Even though the other VR-100's are not at priority status, they will
continue to monitor the channel for activity. If the priority unit were to
leave the scene or become disabled, the other units will detect the
condition to repeat and determine that there is no priority unit repeating
the transmission. They will then begin decrementing their priority
counters until one of them reaches the priority status and begins repeating

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