1. AMATEUR RADIO TRAINING
VHF and Repeaters
Release: v1.21
hamtrain.co.uk

2. USING VHF and Repeaters
Use of “Calling Channel”
Introduction to Repeaters
Repeater “Nets”

3. VHF Calling Channel VHF (Generally line-of-sight).
2 metres 144 to 146MHz
Note the “FM calling” channel on the band plan at MHz
Use this channel to call for someone, or to call CQ
… then move to a different channel for your chat. This frees the “Calling Channel” for others

4. Calling Channel: Example
Listen. If free, call CQ
M6ABC answers and asks you to find a frequency
Tune to a free frequency, e.g
Listen. If nothing heard, ask “is this frequency in use?”
Return to Calling Channel
Call M6ABC and ask them to change to
Tune to
Have your conversation

5. “Repeaters” Repeaters extend ranges across counties & over hills
Most useful for handheld and mobile users.
The UK has over 400 voice repeaters, mostly 2m or 70cm
Mix of Analogue and Digital (DMR, D-Star, Fusion)
Some may also be linked via the Internet

6. Repeater Network Run by volunteers Commonly 2m or 70cm
Frequencies are shared around the UK
Full list at
Smartphone app available
2m repeaters
70cm repeaters

7. How Repeaters Work
A repeater use two frequencies, an “input” and an “output”, so that it can can transmit and receive at the same time.
Typically (but not always):
2m repeaters transmit 600kHz above their input frequency
70cms repeaters transmit 1.6MHz or 7.6MHz below their inputs
Repeaters are “smart”. They only let in valid signals
They have “timeouts” to cut down on long “overs”. Listen for the “K” tone before transmitting, as this resets the timeout
You need to program your radio with the offset, and a CTCSS tone to get access (Store this in a memory)

8. Image source: ukrepeaters.net
CTCSS Tones
Continuous Tone Coded Squelch System
CTCSS is a low frequency tone which is continuously transmitted as part of your audio
Repeaters will only activate if they “hear” the correct CTCSS tone. This blocks interference
There are nine blocks of tones in the UK, identified by letters
You must program your radio to transmit the right CTCSS tone
Image source: ukrepeaters.net

9. Accessing a Repeater When accessing a repeater:
Ensure you have the correct ‘offset’ – Note the Minus sign
Ensure you are sending the correct CTCSS tone – Note the “ENC” or “T” symbol
Store the repeater setting to a memory for easy recall

10. Using a Repeater:
Listen in to your local repeater to learn the etiquette
Callsigns and locations used more often…
“K” is transmitted after an over, to reset the timeout
Don’t call CQ – instead, say “This is M6ABC listening for any calls”
“BREAK” (with callsign) used to join the conversation
Repeater Nets have their own etiquette

11. Summary VHF QSO Find someone using 145.500 FM Calling Frequency
Have your conversation on a free voice frequency
Repeaters
Covers more distance
Radios need to be set for the offset and CTCSS tones
Priority to mobile stations
Listen and learn the etiquette

12. USING VHF and repeaters
Any questions?
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