The Technical Committee
The Milwaukee .91 Repeater is a integrated system of 5 sites located around SE Wisconsin.
General Description of a typical "Remote" site:
Each remote site is exactly the same in design and operation as any other. Due to space and mounting issues, they may be physically laid out differently, but from the functionality and operation aspects, each remote site can be considered a mirror of any other.
Typical Remote Site Equipment Listing:
Diamond 510MA Vertical antenna 2 Meters / 440 MHz
Motorola 2 meter radio 146.310 MHz receive
Scom 5K Controller
Motorola UHF radio TX link to Main Site
3 or 4 Element Beam Antenna 440 MHz
Power Supply / Battery Backup System
In general, a remote site "listens" for a signal on 146.310 MHz via a Diamond 510MA antenna (a 17' vertical). This signal is detected by a 2 meter Motorola radio, and the audio is sent to an SCom 5K controller. The Controller keys a separate radio, which retransmits the received audio via a small Beam antenna aimed toward the Main Site.
General Description of "Main" site:
The Main Site design and function are very different from the remote sites. It uses an SCom 7K controller, and custom programing written by the MRC club programmer to allow for great flexibility and functionality. We have endeavored to create a program for main site that allows for easy basic functionality, AND extended, specific and powerful commands.
Main Site Equipment Listing
Mainsite Antenna System
1 - VHF Repeater antenna - Sinclair SC226-SFXSNM 6dBd gain at 350' 146.310 RX AND 146.910 TX
1 - UHF Remote site receive antenna. - Telewave ANT450D at 350'
2 - TX/RX/Bird Crossband Couple
1 - TX/RX/Bird VHF Duplexer
5 - UHF Bandpass cavities
1 - Kenwood TKR-740 Repeater 146.310 RX & 146.910 TX
1 - Crescend P15-2DB1-C5-001 RF Power Amplifier For 146.910 TX
4 - Motorola CDM-750 UHF radios Remote Site Link Receivers
1 - General Electric Voting Comparator (voter) Selects which receiver's Audio is sent to the 7K
Scom 7K Controller System Control / Telephone Patch
Duracomm Power Supply with Battery Backup and low voltage disconnect
In general, main site listens on 146.310 MHz AND all of the remote link site receive frequencies. All of these audio sources are delivered to a GE Voter, which compares the quality of the audio and tries to pick the "best" signal from all received. This "best" choice of audio is then delivered to the Scom 7K controller for retransmit on 146.910MHz.