Understanding Repeater Operations

1. Understanding Repeater Operations • Presented by: • The Cheshire County DX Amateur Radio Club • AD1T

2. Understanding Repeater Operations Designed by: Joel Huntley WA1ZYX

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

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

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

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

7. Duplex Operations • The Difference in Frequency between Input & Output is called the OFFSET. • Offset is referenced to the Repeaters Output Frequency. • Example: 443.800 Mhz Repeater Output • 448.800 Mhz Repeater Input • Equals +5.000 Mhz OFFSET

8. 10 Meter Offset • -100 Khz • Output 29.620 Mhz • Input 29.520 Mhz • Offset - .100 Khz • Must be GENERAL Class or Above!

9. 6 Meter Offset • -1.00 Mhz • Output 53.090 Mhz • Input 52.090 Mhz • Offset - 1.000 Mhz

10. 2 Meter Offset • - OR + .600 Khz • Depends on Output • Output 146.805 Mhz 147.030 Mhz • Input 146.205 Mhz 147.630 Mhz • Offset - .600 Khz + .600 Khz

11. 1.25 Meter Offset 220 Band • - 1.600 Mhz • Output 224.720 Mhz • Input 223.120 Mhz • Offset - 1.600 Mhz

12. 70 Centimeter Offset440 Band • - OR + 5.00 Mhz • Depends on Output • Output 443.800 Mhz 449.875 Mhz • Input 448.800 Mhz 444.875 Mhz • Offset + 5.000 Mhz - 5.000 Mhz

13. 2 Meter Bandplan • The 144 to 148 Mhz Amateur Radio 2 Meter band plan.

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

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

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

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

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

19. Severe Ice Build-Up • Top of Mtn After Ice Storm

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

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

22. Courtesy Message • Tells the User when the Time-Out-Timer has reset. • Usually after a slight delay to allow for other stations to break in. • 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”.

23. Autopatch • Additional Function of the Controller that interfaces the Repeater to the Telephone System. • 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.

24. Autopatch Do’s & Don’ts • DO Always ID your station prior to use. • DO Limit Autopatch Use to Necessary calls only. • Use Phone BEFORE you leave the Office. • 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!!!

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

26. CTCSS / PL / CG • In Repeater Early days, “PL” was used to keep stations out - ie, “Closed” Repeater. Available to members only. • 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. • Also Used to keep Interference out of Repeater.

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

28. Block Diagram Antenna Receiver Input 448.800 Transmitter Output 443.800 Duplexers Controller Power Supply

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

30. 443.800 MHz 141.3 PL UHF Motorola Micor Keene Repeater Power Amp Transmitter Audio & Squelch Receiver Power Supply Duplexers Controller

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

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

33. The End • If you have any questions….. Contact: • Joel , WA1ZYX at • jhuntley@keene.edu December 1998