– Radio at EMF Camp – POCSAG Paging MB7PMF

MB7PMF is a POCSAG Paging transmitter connected to the DAPNET system

  • Call Sign: MB7PMF
  • Location: EMF Camp – Eastnor Castle (IO82TA)
  • Mode: POCSAG
  • Band: 70CM
  • Output Frequency: 439.9875 MHz
  • Output Power: 7 dbW (5W)

Pager technology, once the bane of anyone on call, has been reinvented by the amateur community in a distributed system which can be used to push alerts and other useful messages in the form of DAPNET (Decentralised Amateur Paging Network).

We thought it would be a fun and entirely appropriate technology to bring to EMF.

Hardware

MB7PMF is largely the same as the transmitter described on the DAPNET wiki here. The notable differences being the use of a Motorola GM900 instead of a GM1200, the addition of hardware to remotely disable the radio and a very over-engineered software/infrastructure deployment.

Full details of all this will appear somewhere eventuallyTM.

Pagers

This page on the DAPNET wiki has a good overview of compatible pagers that will work with DAPNET. SDR based options and the protocol spec are also easy to find for homebrew solutions.

The wiki also details how to program Skyper and non-Skyper pagers to receive pages both directed to you and containing rubric news.

Dan/M0NXN is frantically working on firmware for TTGO/ESP32 based 433MHz LoRa boards (such as this) to allow them to be used as pagers, stay tuned for details. If successful this provides the lowest cost pager using hardware that has a wide range of other uses (compared to a ~£45 AlphaPOC which is a pager and nothing more).

Data

MB7PMF is in the uk and uk-all transmitter groups on DAPNET, so anything targeting those groups will be transmitted.

There is a rubric (emfcamp, rubric number 67) for EMF Camp specific traffic. It is planned to use this for transmitting the event schedule and general announcements during the event.