Accessing GB3NM

To access the repeater you will need an FM transceiver capable of UHF

Output frequency : 433.175Mhz

Input frequency: 434.775Mhz

CTCSS: 71.9Hz

Deviation: Wide

Status: On-Air!

Site engineer: M0VUB

Please note: In order to operate the repeater correctly you must have a +1.6Mhz offset programmed to automatically shift your radio over to the repeaters input frequency while transmitting. PLEASE USE WIDE DEVIATION 5Khz (25Khz Bandwidth).

*Note this is a standalone talk-through repeater designed for local and wide area use via RF only!

MMDVM FM (Standalone)

Time-out

The MMDVM FM logic is fitted with a reasonable timeout which will switch off the transmitter if a signal is received continuously for an unreasonably long time. This timeout should never operate in normal use. If on the rare occasion the repeater does time out you will indeed know about it!

CTCSS 71.9Hz

Access to the repeater via RF requires a sub-audible CTCSS Tone. CTCSS 71.9Hz. CTCSS is the primary way of accessing the repeater via RF which helps reduce any opening of repeaters on adjacent frequencies or geological locations within the RF “over-lap”. It is a requirement by the NoV to have CTCSS as primary access to open the repeater. CTCSS 71.9Hz is also sent by the repeater transmitter when a signal is being received on the input. Between overs the repeater stops sending CTCSS. This means that if you run your radio with CTCSS muting (tone squelch) you will only hear speech, never any confidence pips or Morse beacons. If you do want to hear the pips etc. switch off your CTCSS tone squelch decoder on your radio. 

Wide Deviation

It is imperative you program your radio for WIDE deviation. Set your radio for 25Khz Bandwidth (5Khz deviation). If you use narrow (12.5Khz bandwith) the repeater will sound distorted and you will sound quiet into the repeater.

Voice ID (New)

A Long Voice ID with some detail on how to access the repeater and a website link of www.gb3nf.co.uk/gb3nm on the hour! Followed by a CW-ID on the transmission tail.

A Short Voice ID every 20mins. The standard CW-ID will still run at the end of the repeater’s tail transmission on QSO, keyup (1s or more) and Voice ID.

The MMDVM logic has been interfaced to an AllStar Node, 40071, for Voice telemetry, future weather reports and a listen in feature. There is no access to the repeater from the AllStar or EchoLink networks via another RF Personal node or Network node. We have done this to preserve its local heritage of the repeater and its local users.

Access (RF)

The MMDVM FM logic provides all logical control of repeat talk-through & functionality of the repeater. Developed by Jonathan Naylor, the MMDVM is considered to be the most popular homebrew application built by a digital genius. Paired with the Nokia BSR 450LN rack mount chasis, the Motorola TX/RX units provide a basic talk-through repeater system with access by a 71.9Hz CTCSS sub-audiable tone. YOU SHOULD SET YOUR RADIO FOR WIDE (25Khz Bandwith) 5Khz DEVIATION.

When accessing the repeater from cold you should press the PTT and announce your callsign. This will give time for the repeater to activate. Once accessed you may use the repeater to make a QSO leaving suitable gaps between overs. The repeater will announce it’s ident every 10 minutes while in QSO at a reduced volume. When you have finished your over the repeater will ackowlege with a K in morse.

The repeater is set up with a standard kerchunk timer. “keying/kerchunking up” the repeater to ‘see if you are in’ without identifying yourself is considered inconsiderate and technically illegal. 

Internet Gateway (Telemetry Only)

The MMDVM FM logic adds modern capabilities to the functionality and maintenance of the repeater. The repeater is stand-alone FM only, with a limited AllStar ASL3 setup for voice annoucments, weather and a possible listen in feature. (Coming Soon).

This repeater is stand alone talk-through repeater only. No plans are to link this to any wide area network.

Modern Logic. Modern Era.

Future Features:

  • AllMon3 Dashboard
  • Listen In
  • Weather announcements
  • RepeaterPhone App

“Enjoy, use, but don’t abuse. Re-established at the height of the Pandemic 2020”

-M0VUB, Shane”