145.310 MHz Repeater Site

The 145.310 Mhz repeater site is located atop Mt. Thorodin at an elevation just under 10,500 feet, approximately 12 miles southwest of Boulder, Colorado. This repeater has reliable coverage from Cheyenne, Wyoming to the north, Monument, Colorado to the south, Limon, Colorado to the east, and the continental divide to the west.

The Mount Thorodin repeater site is the hub of the Connection. There is a UHF linking repeater located at this site along with the 145.310 MHz VHF repeater. Both VHF and UHF repeaters are GE Master II commercial units converted to amateur use. VHF duplexers and UHF duplexers are from WACOM. The VHF repeater uses a DB Products four bay folded dipole antenna and the UHF repeater uses a antenna mounted atop the VHF antenna. Links on UHF allow for semi-duplex operation between the Colorado Springs (145.130 MHz) repeater, the Breckenridge (146.790 MHz) repeater, and the Akron (145.400 MHz) repeater. The Kremmling (147.075 MHz) repeater links via VHF on the input to the 145.310 repeater.

As the hub of the system, a Link Communications RLC-5 voice controller is used at this site. We utilize the digital voice recorder to announce information about the Connection. It's primary purpose is to inform users of the 123.0 Hz sub-audible tone required for accessing the Connection. If you ever need our address, just send '411' on your DTMF pad and an informational voice message will be played. (Don't forget to identify your station.) The 411 command is available to the users accessing the Mt. Thorodin repeater directly or up to one hop away. Perhaps we'll expand this feature to other repeaters in the future. We have a 10 second remotely recordable 'Announcement' slot available to inform users of late breaking news. If you have an announcement you'd like to make statewide, contact W0IG and we'll see if we can accommodate your request. Additionally, the RLC-5 has been set to timeout after two minutes. More lengthy transmissions prevent others from utilizing the system.

When you use the system, you'll hear a 'K' (dah-dit-dah) proceed tone. You may notice there are two different 'K's - one is fast, the other slow. The fast 'K' is generated via a signal input to the VHF port at the Mt. Thorodin site. This would include signals local to the 145.310 repeater or signals from the 147.075 Kremmling repeater (which links via VHF to the Mt. Thorodin site). All other signals link to the Mt. Thorodin site via UHF and cause a long 'K' proceed tone.

We're frequently asked the frequencies of the UHF links. We don't give them out for a reason. If you use the UHF links, portions of the system will only link in one direction, rendering your audio unheard on some repeaters. We discourage the use of our UHF links for this reason.

As seen below, the Thorodin repeater package is pretty tightly packed! In order to keep our rent to under $150 per month, we had to fit our equipment into a two foot square, no higher than four feet from the floor!

Mt. Thorodin, Colorado

The Flatirons of Boulder, Colorado, with Mt. Thorodin (home of the 145.310 MHz repeater) in the rear.


Our work crew inspecting the antenna location prior to antenna installation.

Connection volunteers getting ready to erect the 145.310 repeater antennas.

Continued preparations for antenna installation at the Mt. Thorodin repeater site.

The work crew just about ready to erect the folded dipole for the VHF repeater.

After installation, our antenna is the highest on the building! (UHF antenna not shown.)

The VHF repeater mounted on top and UHF repeater on bottom. A lot of heat!


coverage area

Three dimensional map of
Mt. Thorodin and the surrounding area.

Approximate coverage area
of the 145.310 Mt. Thorodin repeater.





Copyright 1996-2015, Colorado Connection Repeaters, Inc.
P.O. Box 22134, Denver, Colorado 80222