Understanding Repeater Operations b Presented by b The

Understanding Repeater Operations b Presented by: b The Cheshire County DX Amateur Radio Club b. AD 1 T

Understanding Repeater Operations Designed by: Joel Huntley WA 1 ZYX

Areas to be Discussed b Simplex Operations b Duplex Operations b Input Frequency b Output Frequency b Duplexer b CTCSS / PL / CG b Controller b Ancillary Functions b Hang - Time b Time-Out Timer b Courtesy Beep or Msg b Autopatch b Offsets b Operating Practices

Simplex Operations b Refers to operations involving ONE RF Carrier Frequency. b Transmit OR Receive, one at a time b Typical Radio User operates in this mode

Duplex Operation b Transmitting AND Receiving at the same time Using TWO Different RF Frequencies. b Typical Repeater Station operates in this mode.

Duplex Operations b. Input Frequency • Repeater Receives on this Frequency • User Transmits on this Frequency b. Output Frequency • Repeater Transmits on this Frequency • User Receives on this Frequency

Duplex Operations b The Difference in Frequency between Input & Output is called the OFFSET. b Offset is referenced to the Repeaters Output Frequency. • Example: 443. 800 Mhz Repeater Output • 448. 800 Mhz Repeater Input • Equals +5. 000 Mhz OFFSET

10 Meter Offset b-100 Khz b Output 29. 620 Mhz b Input 29. 520 Mhz b Offset -. 100 Khz • Must be GENERAL Class or Above!

6 Meter Offset b-1. 00 Mhz b Output 53. 090 Mhz b Input 52. 090 Mhz b Offset - 1. 000 Mhz

2 Meter Offset b- OR +. 600 Khz • Depends on Output b Output 146. 805 Mhz b Input 146. 205 Mhz b Offset -. 600 Khz 147. 030 Mhz 147. 630 Mhz +. 600 Khz

1. 25 Meter Offset 220 Band b- 1. 600 Mhz b Output 224. 720 Mhz b Input 223. 120 Mhz b Offset - 1. 600 Mhz

70 Centimeter Offset 440 Band b- OR + 5. 00 Mhz • Depends on Output b Output 443. 800 Mhz b Input 448. 800 Mhz b Offset + 5. 000 Mhz 449. 875 Mhz 444. 875 Mhz - 5. 000 Mhz

2 Meter Bandplan b The 144 to 148 Mhz Amateur Radio 2 Meter band plan.

How to Locate Repeaters b Repeater Directory is divided First by Band, then State, then by Region North, South, Central etc, then by actual location.

Duplexers Antenna To Rec b Allows Repeater to Transmit same time on ONE Antenna From Xmtr & Receive at the

Types of Repeater Antennas b Commercial Grade Repeater Antennas. b Folded Dipole Style. • Can be configured for Omni or Directivity. b Station. Master, Fiberglass Style

Feedlines b Most Repeaters use Commercial Grade antenna feedlines. b Higher Frequencies and long runs for high towers mean huge signal losses with cheap cable. b Larger cable, lower losses. Andrews or Cablewave 7/8” Foam

More on Antennas b No “Ringo’s” or Flimsy Antennas should be used on High Mountain Top Installations! b Need to be RUGGED!! b And Here’s Why……………. . .

Severe Ice Build-Up b Top of Mtn After Ice Storm

Controller b Interfaces the Receiver by providing Logic and Audio to the Transmitter. b Provides Automatic ID of Repeater b Provides Timers, Messages and other Functions

Timers b Hang / Tail Timer • Amount of Time the Repeater Transmitter stays on-the-air after User Stops Transmitting. b Courtesy Timer • Time between User end of transmission and Courtesy “Reset” beep. b Time-Out-Timer • Amount of time before Repeater Transmitter shuts off. Usually about 3 minutes.

Courtesy Message b Tells the User when the Time-Out-Timer has reset. • Usually after a slight delay to allow for other stations to break in. b If a User begins Transmitting Prior to the Courtesy Message, Previous Users Time is added to your Time. • After 3 minutes, Repeater will “Time-Out”.

Autopatch b Additional Function of the Controller that interfaces the Repeater to the Telephone System. b No business calls allowed. • Although because of deregulation, some “commercial” type calls are allowed now. • Ultimately, it’s up to each Repeater Owner/Trustee. Ask first.

Autopatch Do’s & Don’ts b DO Always ID your station prior to use. b DO Limit Autopatch Use to Necessary calls only. • Use Phone BEFORE you leave the Office. b DON’T Use Autopatch to avoid a Toll Call! • Remember, Somebody’s paying for that Phone Line. Ma Bell Doesn’t give those away to anybody!!!

CTCSS / PL / CG b CTCSS = Continuous Tone Coded Squelch System • PL = Private Line “Motorola’s Trade Name • CG = Channel Guard “General Electric’s Trade Name b Sub-Audible Tone, superimposed on a Transmitted Signal to open a Receivers Squelch. b If a Receiver hears a Signal With the Correct Frequency CTCSS Tone, Squelch Opens, otherwise it ignores the signal.

CTCSS / PL / CG b In Repeater Early days, “PL” was used to keep stations out - ie, “Closed” Repeater. Available to members only. b Now, because there are so many repeaters, and frequency pairs are becoming scarce, “PL” allows a user to “Select” which Repeater one brings up in overlapping areas. b Also Used to keep Interference out of Repeater.

Ancillary Functions b Other Functions provided by a Repeater might be Linking to other Repeaters for “Wide Area” Coverage. b Severe Weather Alerting.

Block Diagram Antenna Receiver Input 448. 800 Duplexers Controller Power Supply Transmitter Output 443. 800

Finished Product b. The End Result After Putting It All Together!

UHF Motorola Micor Keene Power Amp Repeater Transmitter Audio & Squelch b 443. 800 MHz Receiver 141. 3 PL Power Supply Duplexers Controller

Operating Practices b Speak in PLAIN Language b Remember, Don’t give a user a Signal Strength report on a Repeater. YOU ARE REPORTING the REPEATERS STRENGTH!! b Use Normal Words!!!! b Destinated? What “is” that word…. . b Handle? I have no Idea - What’s your name? b Break 19 -- Nope, I don’t Think So!!!

Finances Required b Repeater 1 -2 K, if actual Repeater. Probably less if a converted mobile unit. b Duplexer $500 and up depending on Band. b Antenna $300 - $1000, Again depending on Band / Style b Feedline $3 to $6 per Foot Typical for Heliax. b Connectors for Heliax $60 - $80 each, 2 req. b Controller $500 - 1 K Depending on Features

The End b If you have any questions…. . Contact: b Joel , WA 1 ZYX at b jhuntley@keene. edu December 1998