K0NR Repeater

30 Million Microwatts of UHF Power

The KØNR amateur radio repeater is a UHF repeater operating on 447.725 MHz with an input frequency of 442.725 MHz (- 5 MHz offset). This repeater is a local coverage system located in Colorado near the top of Monument Hill (Palmer Divide) at 7500 feet in elevation.

Repeater Access

This repeater is on “open machine” and all properly licensed and well-behaved amateur radio operators are invited to use it. The repeater requires a 100 Hz CTCSS tone on the input signal. (It also transmits a 100 Hz tone on the output which can be used to limit interference problems on the receive end.)

Tri-Lakes Monument Fire Radio Association

The repeater is often used as a resource for the WØTLM radio club and the Tri-Lakes Fire District Communications Auxiliary. In particular, the Tri-Lakes Net is held every Monday evening at 8 PM local time (unless there is a WØTLM club meeting that night).

Repeater Hardware

The repeater consists of two Motorola Mitrek radios used as transmitter and receiver, controlled by an SCOM 7K Repeater Controller. The SCOM 7K has an optional autopatch board and speech synthesis board installed. The duplexer is Decibel Products 4-can UHF duplexer.  The transmitter puts out about 30 Watts, which is fed to a Hustler G270 dualband  (146 MHz, 440 MHz) antenna.

Emergency Power

The repeater uses a deep cycle marine-type 12V battery with a 5 Ampere “Smart Battery Charger” from A&A Engineering to provide an emergency power source. If the AC line goes down the repeater will continue to operate off the battery for many hours. The repeater does not indicate that it is on battery power.

Autopatch

The repeater has an autopatch which is closed (available only to designated control operators.) Besides, no one actually uses autopatches anymore.

Weather Alert

A weather radio is configured to always monitor the local NOAA weather frequency on 162.475 MHz. When a weather alert for El Paso County or Douglas County is broadcast by NOAA using the S.A.M.E. Weather Alert system, the repeater will automatically transmit the weather radio audio onto the UHF output. The weather radio is a Bearcat WX100, which is interfaced to the SCOM controller.

2 Meter Remote Base

This repeater also operates as a 2-Meter remote base. A 146 MHz FM transceiver (a Yaesu FT-7800R) is connected to the UHF repeater such that the 2M transceiver can be controlled by a station on the UHF repeater. This allows the UHF repeater user to come into the repeater system on UHF and go out on any 2 Meter frequency (simplex or repeater pair). The main purpose of this feature is to allow small UHF handheld radios to access 2 Meters with a much stronger signal and better antenna location.

The repeater indicates the status of the 2M transceiver via a short voice message after the repeater transmitter drops. If the message says “Two Meter Receive”, the remote base is configured to pass 2M receive audio into the repeater output but does not transmit on 2 Meters. In this mode, users can just use the repeater normally but just be aware that you may hear a signal coming through from the 2M receiver. If the message says “Two Meter Transmit”, the remote base is configured to receive and transmit on 2 Meters. In this mode, signals on the input of the UHF repeater will be transmitted back out on 2M (and on the normal UHF transmitter).  If no message is present, then the remote base is off. Signals coming through from the 2M received have a unique courtesy beep (a low single beep) so users can tell if the signal is on the repeater input or the 2M frequency.

Due to its experimental nature, the Remote Base feature is available only to designated control operators, which basically means me.

Monitoring the International Space Station on 2 Meters

Often, the 2M remote is set to monitor 145.80 MHz which is the amateur frequency used by astronauts on the International Space Station (ISS). A specially modified dualband Kenwood TM-D700A transceiver has been deployed on the space station. This radio has several different configurations, including FM voice, packet and crossband repeater.  If the astronauts are not operating using FM voice, the ISS packet radio station or crossband repeater is usually on. If you hear packet transmissions (digital burps of data) on the KØNR repeater, it is probably coming from ISS. If you hear non-Colorado stations working each other on voice, exchanging grid squares, then you are hearing the voice repeater from the ISS. The uplink frequency for the ISS repeater is 437.800 MHz. Since the 2M remote transmitter cannot transmit on 437 MHz, the KØNR repeater can only monitor the downlink (not transmit on the uplink). You can learn more about the amateur radio on ISS at the ISS Fan Club web page.

Monitoring 146.52 MHz for SOTA Activations

The other frequency that the 2 Meter Remote Base is sometimes set to receive is 146.52 MHz, the 2M FM Calling Frequency. This will usually happen when a Summits On the Air (SOTA) activation likely to occur. The repeater is in a good spot to hear a SOTA station on 2 Meters and they usually call on the calling frequency. You can’t make a legitimate SOTA contact through the repeater but it can make you aware that a summit is on the air.

73, Bob K0NR