AC6V’s GUIDE TO FM REPEATERS
This book is six months in the writing and features the advice of several noted Amateurs and technical gurus.
It is intended for those entering the world of FM Repeaters and Amateur Radio. The guide is written for new users with or without a technical background
CHAPTER 1 SAMPLE – INTRODUCTION
Good Golly Miss Molly, what’s this all about? One might hear “N4ZZZ this is K6XXX, Good morning OM, welcome to San Diego. Handle here is Jack, — Juliet Alpha Charlie Kilo, QTH is El Cajon. You’re not quite full quieting into the machine, about 20% path noise. Your deviation is fine. This repeater W6NWG Whiskey Six Nothing Works Good is located on Mount Palomar. The repeater gets very busy during commute hours so let’s QSY to 146.075, plus offset with a PL of 107.2, QSL”. This is followed by a beep, a quiet period, then the repeater drops off the air. Good Golly Miss Molly, what’s this all about? We will cover all this jargon and terminology throughout the book, but here are quick answers so you don’t have to flip through the Chapters.
CHAPTER 2 SAMPLE – YOUR FIRST VHF/UHF Radio
Typically the new licensee purchases a Handi-Talkie (HT) for VHF/UHF, but later find they are using their first radio mostly in a mobile or at a home base station. A mobile rig can be easily switched back and forth between the vehicle and a base location and offers considerable advantages over an HT. Keep in mind that the VHF/UHF radios are for the most part line of sight transmission and reception; however, repeaters can extend the range considerably. HF is the spectrum for long-range skip communications.
This is not to bad-mouth the HTs, they are great for carrying in your shirt pocket or belt clip for pedestrian use, public relations activities, and traveling light. Just be aware of their limitations and intended use. They certainly can be used for base and mobile applications, but better antennas and DC power sources are definitely something to consider when you settle in on an HT.
CHAPTER 3 SAMPLE – OPERATING SIMPLEX
The communication range between Amateur VHF/UHF FM mobile and hand held radios at ground level, operating simplex (direct) is about five to fifteen miles for mobiles, and just a couple of miles for hand held transceivers. The range depends on the band of operation, transmitter powers, antenna heights, obstructions, antenna gains and receiver sensitivity or noise figures. Essentially it is line of sight.
CHAPTER 4 SAMPLE – HOW REPEATERS WORK
Half duplex (Semi Duplex) – a communications mode in which a radio transmits and receives on two different frequencies but performs only one of these operations at any given time. In half duplex, only one station can talk at a time. Your VHF or UHF radio is operating half duplex when set up for standard repeater use. Example you transmit on 146.13 MHz (can’t hear the other station while transmitting). Then you listen on 146.73 as the other station transmits. Your radio automatically transmits on 146.13 MHz when you press the PTT switch and reverts back to 146.73 MHz to listen when you release the PTT.
CTCSS Continuously Tone Coded Squelch System, also known as Subaudible Tone and “PL” (Private-Line, a Motorola trade name). Commonly used for repeater access. These are specific frequencies between 67 and 254.1 Hz. Hereafter referred to as PL for shortness and common use. PL has encode and decode functions. Encode sends PL to the repeater. Decode is set in your receiver to detect the PL from the repeater – see Tone Squelch below. PL frequencies and corresponding ICOM and Motorola numbers are given at the end of this chapter. In Amateur Radio, many repeaters require users to send the correct PL tone continuously to use the repeater. In fact, some coordinating groups insist on Pled repeaters. This may mean the repeater is “closed,” for use only by members, or it may simply be used to avoid being keyed up by users of another repeater on the same frequency pair. Usually PL is required for phone patching.
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