WEBVTT NOTE Repeaters, and What Tones Really Do 1 00:00:00.000 --> 00:00:12.973 Why a repeater changes everything. A 5 W handheld at ground level talking to another 5 W handheld at ground level is good for perhaps a mile in terrain, less in a city. 2 00:00:12.973 --> 00:00:24.401 The limit is not power, it is that UHF travels essentially line of sight, and two people standing on the ground have a very short line between them. 3 00:00:24.401 --> 00:00:37.837 A repeater sits somewhere high, listens on one frequency, and simultaneously retransmits on another. Both handhelds now need line of sight to the repeater, not to each other. 4 00:00:37.837 --> 00:00:43.628 The same two radios that could not reach across town reach across a county. 5 00:00:43.628 --> 00:01:04.955 The +5 MHz split. GMRS repeaters use one fixed arrangement: Input, a 467 MHz main channel. This is what your radio transmits on. Output, the 462 MHz main channel exactly 5.000 MHz lower. This is what your radio receives. 6 00:01:04.955 --> 00:01:11.838 467.6250 in, 462.6250 out. Always +5.000 MHz, always in that direction. 7 00:01:11.838 --> 00:01:28.027 There is nothing to compute and nothing to choose, which is a genuine mercy compared with the amateur bands, where the offset varies by band and sometimes by repeater. 8 00:01:28.027 --> 00:01:41.308 Most GMRS radios call this a "repeater channel" and set both halves for you. Radios that do not will ask for a transmit offset of +5 MHz. 9 00:01:41.308 --> 00:01:50.707 The two tone systems. A repeater usually requires a tone on its input before it will transmit anything. 10 00:01:50.707 --> 00:02:05.672 Two schemes exist: CTCSS, a continuous sub-audible tone, somewhere between 67 and 254 Hz, transmitted under your voice. Also called PL, after Motorola's trade name. 11 00:02:05.672 --> 00:02:24.652 DCS, a continuous low-rate digital pattern doing the same job. Also called DPL. They serve the same function and are not interchangeable: a repeater expecting CTCSS 141.3 Hz will ignore any DCS code you send. 12 00:02:24.652 --> 00:02:41.077 Each direction is set separately, and the distinction matters: Setting, Transmit tone (encode); What it does, Sent with your transmission. The repeater checks it before keying up.. 13 00:02:41.077 --> 00:02:56.042 Setting, Receive tone (decode); What it does, Checked before your speaker opens. Silences signals that lack it.. To use a repeater you need the transmit tone right. 14 00:02:56.042 --> 00:03:03.068 The receive tone is optional and, for a beginner, actively worth leaving off. 15 00:03:03.068 --> 00:03:19.387 The thing the marketing gets wrong. Consumer radios sell tone squelch as "privacy codes". This is false in every sense that matters. A tone decides when your own receiver's speaker opens. It does not encrypt anything. 16 00:03:19.387 --> 00:03:32.548 Your transmission is ordinary FM voice; anyone within range with an open squelch, any scanner, any radio with tones switched off, anyone using the same tone, hears every word. 17 00:03:32.548 --> 00:03:48.190 The practical damage is not embarrassment, it is interference. Operators who believe in privacy codes hear silence, conclude the channel is free, and transmit straight over a conversation already in progress. 18 00:03:48.190 --> 00:04:03.908 Their radio was silent because the tone did not match, not because the channel was clear. Habit worth building: switch tone decoding off, or hold the monitor button, and listen before you transmit. Every time. 19 00:04:03.908 --> 00:04:18.843 Working a repeater, first time. Find one. Repeater listings are informal, GMRS has no official registry. Local clubs, online directories, and asking on a busy channel all work. 20 00:04:18.843 --> 00:04:36.408 Get the details: output frequency, and the transmit tone. The input is the output plus 5.000 MHz, so nobody needs to tell you that. Programme a channel with the +5 MHz transmit offset and the tone as encode. 21 00:04:36.408 --> 00:04:51.512 Leave decode off while you learn. Listen first. Several minutes. You will learn the local etiquette faster by listening than by asking. Ask permission if the repeater is private. 22 00:04:51.512 --> 00:05:08.314 Many GMRS repeaters are someone's personal equipment on someone's tower, and section 95.1705 lets the owner limit or refuse use. Ask. Key up, pause, then speak. A repeater needs a moment to come up. 23 00:05:08.314 --> 00:05:21.806 Start talking instantly and your first syllable is gone. Identify with your call sign, at the end of your transmission or series and at least every 15 minutes. 24 00:05:21.806 --> 00:05:28.255 Leave a gap between transmissions so someone with an emergency can break in. 25 00:05:28.255 --> 00:05:31.712 When the repeater does not identify itself. 26 00:05:31.712 --> 00:05:48.435 Section 95.1751(c) excuses a repeater from transmitting its own call sign, but only if it retransmits solely communications from stations operating under its own licence, and those stations identify properly. 27 00:05:48.435 --> 00:06:02.424 In practice most repeaters send an identification anyway. Yours is required regardless. Check yourself. A repeater's output is 462.6750 MHz. What does your radio transmit on? 28 00:06:02.424 --> 00:06:18.263 Your radio is silent on a busy channel with a tone set. What is happening, and what should you do before transmitting? Does setting a "privacy code" stop a neighbour from hearing your conversation? 29 00:06:24.263 --> 00:06:45.935 467.6750 MHz, output plus 5.000 MHz. Tone decode is filtering out transmissions that lack your tone. Switch decode off or hold monitor, and listen before transmitting. No. It filters your receiver. 30 00:06:45.935 --> 00:06:53.196 Your transmission is plain FM voice that anyone in range can hear.