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160 metre DF Equipment



This is a simple tuneable receiver with a directional aerial and a sense aerial. The aerial is either a ferrite rod or a loop. The sense aerial is a telescopic whip. The receiver has a BFO (Beat Frequency Oscillator) so that morse signals can be easily heard; this makes a signal with no speech on it sound like a whistle.

The receiver has controls for:

  • Audio gain (volume)
  • RF gain
  • Main tuning
  • Antenna tuning
  • BFO on/off
  • Sense on/off
  • Main on/off


Headphones are used to keep out background noise making weak signals easier to hear.


These vary considerably and can be used in different ways.

Walking compass. A Silva, or similar make, walking compass fixed to the receiver (away from any magnetic materials including a ferrite rod). The receiver is held in the null position and the bezel of the compass aligned with the needle. The bearing is read off the bezel.

Sighting compass. The receiver is held in the null position at arm's length or on the ground; the compass is held in line with it and sighted along the line of the receiver. The bearing is read directly from the compass.

Monitor Receiver

This is a receiver fixed in the car and used to monitor the transmitter frequencies. Many scan the frequencies automatically. it must be connected to a non-directional receiver.  


A 1:50,000 Ordnance Survey map of the area. All the transmitters and the start will be on one map (or an area equal to one map with the boundaries published in advance).

Plotting Equipment

  • Protractor
  • Straight Edge
  • Pencil

Clock Card

A card for use in the transmitting station DF clock

Transmitting Stations


The type of transmitter most commonly used is one designed by Phil Arnold (G4CFG) and Norman Rathbone (G4KZU). Its main features are:

  • contained in an ex-army ammunition box measuring 300 x 185 x 155 mm including the battery and microphone
  • crystal controlled frequency
  • about 10 watts RF output
  • amplitude modulated
  • built-in aerial tuning unit
  • automatic morse generator

DF Clock

A specially designed clock which records the times when the competitor's clock card is inserted. This was designed by Phil Arnold (G4CFG). Its features are:

  • Self contained
  • Continuous display of time to 1 second
  • Records and displays card number and time of first insertion of a competitor's card
  • When a special card is inserted it displays the entry number, card number and time of all inserted cards (so that the transmitter operator can keep a paper back-up copy)
  • Serial port for uploading the recorded information to a computer

Contest Organiser


To upload information from DF Clocks


To print the results

Lots of Wire

For aerials

Tools to get the Wire High into Trees

For example: pole, weights, fishing rod and reel