147.375 MHz Repeater

147.375 MHz Output
+600 KHz Input
Always transmits a tone of 114.8Hz. CTCSS only turned on for speicial uses or interference affecting the radio

Equipment

Motorola Radius R1225
25 Watts output, ERP approximatly 110 watts
0.35 MicroVolt Receiver Sensitivity
WACOM 4-cavity band-pass, notch-reject duplexers, UHF connectors
Diamond X500HNZ dual band antenna (8.3db 2M/11.7db 70 cm), 144 Mhz/440 Mhz diplexer, 1/2" hardline, approximatly 600 feet above ground
Range is approximately 30 Miles using a 1/4 Wave mobile antenna, 5 Watts output; Des Moines, IA coverage using a 50 Watt mobile transceiver.
 

443.375 MHz Output
+5 MHz Input
CTCSS Output of 156.7 Hz
CTCSS Input of 156.7 Hz required

Equipment

Motorola Radius R1225
16 Watts output, ERP approximatly 125 watts
4 Band-Pass Cavities, Notch Reject Duplexers
Same antenna as 2 Meter repeater
Range Approximately 20 Miles with 1/4 Wave mobile antenna, 5 Watts output

Planned Repeater improvements

Add remote base functionality
Restore voice output of certain functions of the repeater
Remote access to controller, radio programming, and monitoring of system via secure Ethernet link

 

ISU Campus map, showing the repeater system site.
 

Operational Details:

• Please observe the CARC repeater usage guidelines.
• Courtesy Tones:
• Single tone : Normal Operation, each repeater operating separately
• Triple-Scale Tones:  Repeaters are cross-linked.  All user transmissions will be transmitted out the 440 MHz and 2 meter repeaters.
• Linking and Unlinking the System:
• To bring the link up, send DTMF 21 while transmitting into the 443.375 repeater.
• To drop the link, send DTMF 23 while transmitting into the 443.375 repeater.
• Autopatch is available either on the 2 meter or 440MHz repeater.  The 2 meter and 440 MHz repeaters share the same autopatch; while the repeaters are cross-linked, autopatches are heard on both repeaters simultaneously.  Normal autopatches are not permitted if either repeater is being used for emergency traffic.  Please read the autopatch instructions before using the autopatch.
• The repeater is located on the Physics Annex Building, Iowa State University campus, Ames, Iowa.  Approximate longitude/latatude is N 42degs, 01mins / W 93deg, 36mins (via GPS, with estimated accuracy of 50 feet).
• The repeater antenna is the top antenna on a 50 foot Rohn roof-top tower, above KURE "white ball" antenna.
• The repeater controller is a Link-Comm RLC-4 with autopatch option.
• Future repeater expansion ideas:
• Autopatch speed dials
• Full-duplex autopatches/Reverse Autopatch
• VHF/UHF remote base
• HF remote base
• Internet remote base
• Voice recorder / announcer
• Net operation, no-tail cross-link mode
Contact the CARC cabinet if you would like to help and assist with funding future repeater expansion projects.