The main repeater for Hospital Disaster Support Communications System (HDSCS) is K6QEH/R, 146.970(-) MHz, PL 136.5 Hz. The weekly HDSCS net (Tuesdays, 1930 hours local) is on this frequency. It is the first repeater for HDSCS members to check/monitor when a widespread communications emergency occurs. This page gives some background and useful operating tips regarding this repeater.
K6QEH/R (then WR6ACQ) was the first "aerospace industry" ham repeater in southern California. Designed and built "from the ground up" by the Hughes-Fullerton Employee Association Amateur Radio Club, it went on the air in 1973 on 146.880(-) atop Building 606 of the company's facility near the Fullerton Airport. The frequency pair was changed to 146.970(-) in December 1979 due to unresolvable co-channel interference problems. An autopatch was added in September 1981 and an auxiliary receiver at 1000-foot elevation in La Habra Heights went into service July 1983. Upon closure of Building 606 in 1994, the repeater was relocated to a new radio room in Building 675 and new towers were installed atop that building to support the repeater antennas. In December 1997, this facility and its employees became part of the newly-merged Raytheon Electronic Systems. Raytheon employees and retirees continue to administer and maintain it.
K6QEH/R on two meters is an open repeater. All well-mannered conversations are welcome. However, autopatch use is limited to hams associated with the sponsoring club, because the patch utilizes the company's telephone system. In an emergency when circumstances warrant, the autopatch can be made available for HDSCS use. Instructions for use will be provided at that time.
The radio room is powered from the building's automatic emergency generator. Also, both the main repeater and auxiliary receiver equipment have battery backup power supplies. If both commercial and generator AC power fail at the radio room, transmitter power will be automatically reduced by approximately 6 dB. As an indication, the CW ID tone (not the courtesy beep) will change from high pitch to low pitch.
K6QEH/R shares its frequency pair with repeaters in Oxnard, Santa Clarita, Trona and Barstow. We have an excellent relationship with the other 146.970 repeater owners/users and we want to keep it that way. You can help by not using high power (more than 50 watts) or large base station antennas to work through our repeater when you are in a location where you might put a strong signal into one of the other machines.
A closed repeater on the 70 cm band is also part of the K6QEH/R system. It can be linked to the two-meter repeater to provide a convenient method of monitoring the main channel during HDSCS activities. For more information, contact the repeater staff listed below.
The repeater timeout period is 90 seconds. If you time out, the repeater will transmit a long "BZZZZZZ" (the razz-berries!) when you unkey and the timer resets.
The "voting" system uses signal-to-noise ratio (quieting) to select the receiver with best audio for retransmission. Switching is rapid, automatic and may occur many times within a transmission.
The normal "high double-beep" courtesy tone indicates that both two-meter receivers are on-line and available. It does not indicate which receiver is being retransmitted. If one of the receivers is out of service, the courtesy beep changes. "High single-beep" indicates that the remote receiver is offline. "Low double-beep" means that the Fullerton receiver is offline.
You will not hear a courtesy beep if:
Key-up of the repeater is slowed slightly by response time of the CTCSS decoder and voting system. When using this repeater, remember to hesitate a half second to a second after pressing your PTT before beginning to speak. If you start talking too soon, the decoder may not engage for an even longer period and your first words won't be heard.
The Fullerton receiver has very steep bandpass characteristics and an off-frequency lockout circuit to prevent interference from a repeater that is 15 KHz above our pair. Your signal must be on frequency and deviate less than 5 KHz peak to be properly retransmitted through K6QEH/R. If someone tells you that your signal is distorted or "cutting out," check your 5 KHz switch (i.e. verify you are tuned to 146.970 and not 146.975). If frequency is correct and the problem persists, back off from your mike and talk more softly.
Don't expect "hi-fi" audio through this or any other well-engineered repeater. Low frequencies are deliberately rolled off to filter out subaudible tones. High frequencies are restricted as a courtesy to prevent QRM to adjacent channel repeaters. Intelligibility is still very good, despite these restrictions, if you keep your deviation at the proper level.
One last request: It is club policy to not talk on the air about the upcoming or ongoing out-of-town trips of other hams, to protect their property and families. There are a lot of listeners out there!
For more information on the repeater, contact Tom Gaccione WB2LRH (K6QEH Trustee) or Joe Moell KØOV (Repeater Technical Advisor).
In the photos: Original La Habra Heights tower above left, part of K6QEH radio room above right, Fullerton site antennas below.
Read a company newspaper article about the sign-on of this repeater in 1973
Or go back to the HDSCS home page
This page updated 12 January 2015