Repeaters
Overview
Repeaters allow hams using VHF frequencies (usually in the 2 meter [144Mhz]) band to communicate over the horizon, or in mountainous terrain where line of site communications is blocked by such things as mountains or tall structures. They are also useful for hams "passing through" an area using mobile equipment. The Murphy Radio Club operates a repeat on Joanna Bald, in Andrews, Cherokee County, North Carolina for use by any amateur radio operator.
How a Does a Repeater Work
An amateur radio repeater is a device that receives a weak signal from a radio station, amplifies it, and re-transmits the signal at a higher power to reach a wider area. Here‘s how a repeater typically works:
- A radio user transmits a signal to the repeater on the "input" frequency. The signal is weak and may not reach the repeater if the user is far away or obstructed by buildings or terrain.
- The repeater "listens" for signals on the input frequency using a receiver that is tuned to that frequency. When it receives a signal, it demodulates the audio and processes the signal using a repeater controller, which may provide additional features like tone squelch or call sign announcement.
- The repeater then amplifies the signal to a higher power and re-transmits it on the "output" frequency, which is typically a different frequency than the input frequency. The output frequency is usually chosen to avoid interference with other nearby repeaters or radio systems.
Below are the definitioins of several repeater terms:
- Uplink
- The frequency used by your radio to transmit your signal to the repeater.
- Downlink
- The frequency that the repeater used to send a signal from another radio to you.
Some Local Analog Repeaters
| Location | Call Sign | Frequencies (Down/Up) | Offset | Tone | Notes |
|---|---|---|---|---|---|
| Joanna Bald, Andrews, NC | K4AIH | 147.045 146.445 | -0.60MHz | 151.4 151.4 | WCARS-Murphy net. Primary Cherokee County SKYWARN Net and Echo Node Link KD4UYR/R. |
| Joanna Bald, Andrews, NC | K4AIH | 443.650 448.650 | +5.00MHz | none 151.4 | K4AIH UHF Link to Channel 1 |
| Poorhouse Mnt., Brasstown, NC | K4CTE | 147.315 147.915 | +0.60MHz | 103.5 103.5 | Secondary Repeater fo WCARS-Murphy net and the Cherokee County SKYWARN Net |
| Rocky Top Mnt, Blairsville, GA | K5PRE | 146.955 146.355 | -0.60MHz | none 100.0 | Appalachian Emergency Net Frequency (Clay Co, Nc AUXCOMM) |
| Oswald Dome, Benton, TN | KA4ELN | 147.375 147.975 | +0.60MHz | 123 123 | SE Tennessee ARS, FM AllStar, EchoLink P-25 |
| Mt. Oglethorpe, Jasper, GA | KC4AQS | 146.805 146.405 | -0.40MHz | 100.0 100.0 | GA SKYWARN - Part of the GA Statewide Net |
| Culhowee Bald, Franklin, NC | KF4RC | 145.490 144.890 | -0.60MHz | none 167.9 | Macon County |
| Wauchaucha, Graham County, NC | N4GSM | 145.110 144.510 | -0.60MHz | 151.4 151.4 | Smokey Mountains Amateur Radio Team (SMART) |
| Wine Springs Bald, Franklin, NC | W4GHZ | 147.240 147.840 | +0.60MHz | none 151.4 | Macon County AUXCOMM Net |
| Oswald Dome, Benton, TN | W4GZX | 146.925 146.325 | -0.60MHz | 118.8 118.8 | SE Tennessee SKYWARN |
| Crossville, TN | W4KEV | 147.345 147.945 | +0.60MHz | 118.8 118.8 | Crossville, TN Area Hams |
| Crossville, TN | W4MBR | 443.875 448.875 | +5.00MHz | 88.5 88.5 | Middle TN Emergency Amateur Network |
| Oswald Dome, Benton, TN | WD4DES | 442.250 447.250 | +5.00MHz | 118.8 118.8 | UHF Backup for KA4ELN |
Some Local DStar Repeaters
| Location | Call Sign | Frequencies (Down/Up) | Offset | Tone | Notes |
|---|---|---|---|---|---|
| Benton, Tenneesee | K4AJM | 144.980 147.480 | +2.50MHz | none DV | Usually connected to North America Chat Reflector 30C |
| Brawley Mountain, Morganton, GA | KM4MAD | 145.400 144.800 | -0.60MHz | none none | Georgia Interlinked DStar system used for Health and Safety during emergencies on Reflector 30B |
| Oswald Dome, Benton, TN | KM4MCN | 147.480 144.980 | -2.50MHz | none none | North American Reflector 030 |