About the K9VI Repeater System
The K9VI group operates repeaters on 51.910 / 52.910 PL 114.8Hz and 223.100 / 224.700 PL 100.0Hz. Co-located at the site are 2 UHF and 1 VHF machines operating on 145.33 / 144.73 PL 107.2Hz, 443.475 / 448.475 PL 114.8Hz, and 443.200 / 448.200 PL 131.8Hz. These machines are open for all amateurs to use, except we request that priority traffic take precedent during severe weather or any other emergency usage of the machines. The 6M machine, a might dual-8650AS high power Micor base station, operates at a power of 250 Watts TPO with an antenna gain of 3dB. The antenna is located at 475 feet AGL. Both UHF machines, Motorola Quantar systems, operate with TPO of 100 watts and the 222 machine, a Motorola MOF230 repeater developed for the Indonesian Government / Minsitry of Forests, operates with a TPO of 25 watts respectively, with a center of radiation at 460 feet AGL. Finally, the VHF machine, a Motorola MTR-2000 repeater, operates at a power level of 125 watts with a center of radiation of 330 feet AGL. Ground level at the base of the tower is 890 feet AMSL. We thank the owners of WZSR (Star 105.5), NextMedia, for the tower space they generously provide for our systems. In exchange, we provide engineering and other services on an as-needed basis. The repeaters and control systems are neatly contained in 2 rack units, including monitoring of the statewide emergency channel (EAS channel for Illinois) on 45.44MHz utilizing an Aerotron receiver (the original K9VI 6 meter repeater recevier re-crystaled for the IEMA frequency) and the NOAA National Weather Service local transmitter, co-located on site, operating on 162.500MHz as well as Rockford on 162.475 and Racine on 162.450MHz; all NOAA weather transmissions are monitored by Motorola AstroTAC receivers. Finally, the Chicago system on 162.550 is also monitored for activity. In this fashion, we pass alerts as decoded by a Sage EAS ENDEC decoder, for Cook, McHenry, Kane, Boone, Lake, and Winnebago counties in Illinois as well as Racine, Kenosha, and Walworth counties in Wisconsin. The third unit is the 6 meter repeater. The Sage ENDEC unit monitors the National Weather Service and IEMA channels for emergency messages. The 6M audio path is broken to carry this information as it is received. Here is a photo of the repeater racks:
I hope to post better pictures of the system very soon. The 6 Meter and 222Mhz systems are currently linked. In the near future, the 443.475 and 145.33 UHF and VHF systems will also be linked. These systems are coordinated to N9HEP. We are also working to add additional receive sites for the 6M system. Finally, have an antenna on the tower at 390 feet to add an APRS gateway to the system.
In addition to the repeater work, I also do a limited amount of broadcast engineering; mainly to keep current in that field of work. I have been working closely with the great people over at WGN radio in Chicago since 1985 and I have been involved with WRPQ radio in Baraboo, where I am a stockholder. WGN and WRPQ are are opposite extremes of the AM broadcast industry. WGN is a 50kW clear channel station that generates tens of millions of dollars in revenue each year in the third largest city in the US - Chicago. WRPQ is a 250 watt daytimer with an after hours operating authority for 6.4 watts. Yet, WRPQ serves the greater Baraboo, WI region as well as any big city station. Please enjoy a few pictures of each station, plus a few more of the more than 250 stations I have performed engineering work at around the world over the past 25 years.
The new ATU under construction for WRPQ An oblique view with the turns counter installed on the cap.
RF Design by Greg Buchwald, construction by Jim Taylor and Greg Buchwald